MYSORE

Proceedings of National Workshop on

Recent Advances in Geotechnics

for Infrastructure

RAGI 2020

Edited by

Dr. S.K. Prasad

&

Dr. S. Raviraj

MYSORE

14-17 May, 2020

i

MESSAGE

Prof. Aswath M.U.

The main object of the Association of Consulting Civil Engineers

(India) is to encourage and foster the ideals of the profession, to

bring to the members the latest technological advancements in the

world, prepare them to carry out futuristic designs with an eye on

assurance of quality, to give access to technical resources, to hold

conferences, workshops, seminars and arrange lectures by

distinguished engineers from India and abroad and to conduct study

tour of projects. The purpose is dissemination of knowledge

amongst the civil engineers in particular and the society at large.

Mysore center is one of the very vibrant centers of ACCE (I). The center is active in

organizing various activities like technical interactions, seminars, site visits, etc. for the

benefit of the members in particular and society in general. During the present Global crisis

due to the pandemic Covid-19, the members of Mysore center have shown their social

responsibility in helping the needy. I would like to place on record my appreciation to all the

members of Mysore center.

ACCE (I)-Mysore Centre has been organizing their flagship event RAGI-Recent Advances

in Geotechnics for Infrastructure successfully for the benefit of civil engineering

community. This workshop is jointly organised by Association of Consulting Civil Engineers

(ACCE), Mysore Centre, Indian Geotechnical Society, Sri Jayachamarajendra College of

Engineering (SJCE) and The National Institute of Engineering (NIE). On behalf of ACCE (I),

I extend my sincere thanks to Indian Geotechnical Society, SJCE and NIE for their

continuous support.

I have seen over the years, the organizing committee takes enormous efforts in organizing

this event RAGI. Generally the focus of the workshop is to introduce modern methods in

geotechnical aspects of infrastructure development to Engineers, Builders, Consultants,

Developers, Students and Architects.

Due to the present crisis, the Mysore center has taken special interest to organize this event

through online mode instead of cancelling. This deserves a special mention of thanks to all

the organizing team members. I am sure RAGI-2020 will add value to all the participants and

will be a great success.

My best wishes.

Prof. Aswath M.U.

President-ACCE (I)

Bengaluru

ii

MESSAGE

Prof. G.L. Sivakumar Babu

The subject of Geotechnical Engineering has become an

essential source of knowledge for civil engineers in designing

and constructing physical infrastructure in the form of dams,

highways, buildings, bridges, geo-environmental and waste

management solutions etc. and in improving the knowledge of

effects of natural hazards such as landslides, soil contamination

and many other related areas using geotechnical engineering

principles. The scope has widened and the effect of these developments in the area have been

so enormous resulting in improved infrastructure, cost effective designs and solutions to many

problems. Civil engineers will get immensely benefitted if there is periodic exposure to these

developments.

In this context, the technical event, Recent Advances in Geotechnics for Infrastructure

(RAGI) being conducted in the form of webinar in May 2020 during the period of pandemic

is timely and appropriate. The national workshop is jointly organised by two professional

organizations, namely, Association of Consulting Civil Engineers (ACCE) Mysore Centre,

Indian Geotechnical Society, Bengaluru Chapter and two renowned centres of learning,

namely, Sri Jayachamarajendra College of Engineering (SJCE) and The National Institute of

Engineering (NIE).

I am sure that the deliberations in the webinar will benefit many Engineers, Professionals,

Teachers and Students.

Prof. G.L. Sivakumar Babu

President, Indian Geotechnical Society

Bengaluru

iii

MESSAGE

Dr. Rohini Nagapadma

It is a pleasure that the organizers of RAGI-2020 are

proposing an online webinar on ‘Recent Advances in

Geotechnics for Infrastructure’ during May 2020. In the

present situation of global pandemic, I am extremely happy

that the organizers of RAGI-2020 prudently thought about

reaching out to as many professionals as possible across the

country through this seminar. With the proposed webinar,

sixth edition of RAGI will be successfully launched. I am

pleased that The National Institute of Engineering is a part of

RAGI, organizing along with Sri Jayachamarajendra College of Engineering, Association of

Consulting Civil Engineers (I), Mysore Center and Indian Geotechnical Society, Bengaluru

Chapter. I am very confident that RAGI-2020 will be as successful as the previous editions in

imparting the technical knowledge in Geotechnical Engineering to the professional engineers.

I wish the event a grand success.

Dr. Rohini Nagapadma

Principal

The National Institute of Engineering

Mysuru

iv

MESSAGE

Dr. T.N. Nagabhushana

It gives me immense pleasure that biennial national workshop on

Recent Adavances in Geotechnics for Infrastructure RAGI-2020 is

being held this year under difficult situation as a webinar. I appreciate

the efforts by the organizers to improvise during the pandemic period

to reach out to more number of professionals. Research advances in the

field of Geotechnical Engineering is very much critical to create better

infrastructure in the 21st century. The Team ‘RAGI-2020’ has been

working to bring the best expertise available in this area and make it available to all the

stakeholders. I personally congratulate the entire team RAGI-2020 for their untiring efforts in

making this event a grand success.

Dr. T. N. Nagabhushana

Principal

Sri Jayachamarajendra College of Engineering

Mysuru

v

MESSAGE

S. Prakash

A Civil Engineer’s challenge starts with soil. Different soils may show

different characters like expansion, shrinkage, undergo excessive

settlement, have a distinct lack of strength or be corrosive, making the

study in geotechnical engineering very challenging. Our geotechnical

engineers have proved that they are one among the best in the world.

ACCE(I) Mysore centre has been in the forefront in conducting the

exclusive National webinar on RAGI – Recent Advances in Geotechnics for Infrastructure. I

am happy that, this is the 6th edition of RAGI, and we have very eminent speakers hailing from

different parts of the country. There will be a lot of knowledge sharing happening. I wish all

the delegates a happy learning.

Meticulous planning has been done for the success of this event. I congratulate and convey my

best wishes to the Chairman Dr. H.S. Prasanna and the Hon Secretary Dr. S. K. Prasad and the

organizers. NIE and SJCE managements have been strong supporters of ACCE(I) activities. I

thank both these organizations.

I wish the webinar a grand success

S. Prakash

Chairman, ACCE (I) Mysore Centre

Mysuru

vi

MESSAGE

Dr. C.R. Parthasarathy

I am extremely happy to know and be a part of the virtual National

Workshop (through Webinar) on Recent Advances in Geotechnics for

Infrastructure (RAGI 2020). The workshop was earlier planned on

21st March 2020, but had to be extended due to lockdown. RAGI used

to attract people from Academics, Research, Students and Industry, but

this webinar will enable to reachout to wider audience through out the

country and abroad as well.

There are eminent speakers who will share/dessiminate knowledge on the important topics of

Geotechnical Engineering with particular reference to Infrastructure. The hosting of virtual

workshop will bring in new dimensions in organising such programmes in the coming days.

I am honoured to patronise the workshop and on behalf of Indian Geotechnical Society-

Bengaluru Chapter, wish this webinar all the success.

Dr. C.R. Parthasarathy

Chairman

Indian Geotechnical Society-Bengaluru Chapter

Bengaluru

vii

MESSAGE

Dr. K.C. Manjunath

Recent Advances in Geotechnics for Infrastructure (RAGI) is a very

popular biennial activity conducted by ACCE(I), Mysore Centre in

association with two reputed engineering colleges of Mysuru city, The

National Institute of Engineering (NIE) and Sri Jayachamarajendra

College of Engineering (SJCE) and Indian Geotechnical Society

Bengaluru Chapter. This year RAGI-2020 is being presented as a

National level webinar with experts delivering talk on latest developments in the field of

Geotechnical Engineering. I wish a grand success for the webinar and hope it will be helpful

in delivering the latest information to Academicians, Consultants and practicing Engineers in

the field of Geotechnical Engineering.

Dr. K.C. Manjunath

Professor & Head

Civil Engineering Department

The National Institute of Engineering

Mysuru

viii

MESSAGE

Dr. K. Prakash

The biennial national workshop on “Recent Advances in

Geotechnics for Infrastructure (RAGI 2020)” is being organized

in collaboration with ACCE (I) (Mysore Center), IGS

(Bengaluru Chapter) and NIE, Mysuru, for the benefit of

Engineers, Builders, Academicians and Designers belonging to

Mysuru region. However, the ongoing COVID disaster did not

allow conventional workshop. I am proud and happy that the organizers have

improvised this workshop as an online webinar and are proposing to reach out to

many professionals across the country. As in the previous workshops, eminent people

in the field of Geotechnical Engineering will be delivering lectures of practical

importance. The workshop aims at updating the participants about the latest

developments that have taken place both in theory and in practice in various

infrastructural development projects. It is hoped that this workshop / webinar would

help the people working in construction industry and academia as well.

Dr. K. Prakash

Professor & Head

Department of Civil Engineering

Sri Jayachamarajendra College of Engineering

Mysuru

ix

ASSOCIATION OF CONSULTING CIVIL ENGINEERS (INDIA)

The Association of Consulting Civil Engineers (India), abbreviated as ACCE (I) was formed

in 1985 with head-quarters at Bangalore. The main objective of the association is to

encourage and foster the ideals of the profession, to hold conferences / meetings / seminars

for dissemination of knowledge amongst the civil engineers in particular and the society at

large. It acts as spokes-channel for the Consultants to deal with Government, Corporations

and other agencies regarding policy matters. ACCE (I) has 22 centers in different parts of our

country.

The Mysore Center of ACCE (I) took its birth on the 17th May 2001 with 20 members and

currently has 150 members. Since its inception, the association has organized many technical

programs and workshops to keep the members updated about the technological developments

in the field of Civil Engineering. It has conducted many major events in the past such as

Leadership development program in 2002, Two day National Seminar on Long Span Bridges

in 2004, One day National Workshop on Water and Waste Management in 2009, Two day

National seminar STEELCON on Steel Structures - in 2013, two day national seminars

RACE-2017 & RACE-2019, One day workshop on Recent Advances in Geotechnics for

Infrastructure – RAGI from past six years, Technical talks, Design Safe Colloquium, Best

M.Tech Theses Awards Ceremony, ‘ACCE – Ultratech’ Awards Nite and Industry outreach

program to students of engineering colleges in Mysuru region. This apart, the center also

organizes a number of other technical programs and project visits.

Er. M.S. Ramprasad

Secretary, ACCE(I), Mysore Center

Er. S. Prakash

Chairman, ACCE(I), Mysore Center

x

IGS BENGALURU CHAPTER

Established in 1948, Indian Geotechnical Society (IGS) is one of the top most Civil

Engineering societies in India. IGS aims at promoting co-operation amongst engineers and

scientists for the advancement and dissemination of knowledge in the fields of Soil Mechanics,

Foundation Engineering, Soil Dynamics, Engineering Geology, Rock Mechanics, Snow and

Ice Mechanics and allied fields and their practical applications. It provides a common forum

for academicians, research workers, designers, construction engineers, equipment

manufacturers and others interested in geotechnical activity. Among many activities of Indian

Geotechnical Society are organizing conferences, knowledge sharing through lectures, student

activities through student chapters, young geotechnical engineer conference among many. The

society also brings out Indian Geotechnical Journal through Springer publishers. It has 40 local

chapters out of which Bengaluru is one of the vibrant and most active chapters. It has hosted

many prestigious conferences such as Indian Geotechnical Conferences, Asian Regional

Conference and several international conferences.

xi

The National Institute of Engineering, Mysuru

The National Institute of Engineering (NIE) in Mysuru is one of the leading technical

institutions in the country imparting high quality value based education. NIE was started in

the year 1946 with Civil Engineering stream and it has grown over the years. The institution

now offers various undergraduate, post graduate and doctoral programs in different

disciplines. NIE is approved by All India Council for Technical Education, Accredited by

National Board of Accreditation and assessed by NQA. The institution was accorded

autonomous status under Visvesvaraya Technological University, Belagavi during the year

2007. The prestigious world bank project TEQIP I grants have been utilized for the all-round

development and TEQIP II grants have been used for Innovation and R&D activities. NIE

has now been recognized and selected in to TEQIP III grants where it has the privilege to

mentor a government college in Uttar Pradesh. NIE has highly qualified and competent

faculty and state of the art infrastructure. Over the years NIE has established centers of

excellence in various fields of engineering. Impressive placement record, regular short term

courses for students and working professionals, consultancy services, interaction with

industry, training programs to aspiring students by means of additional certificate / diploma

programs through experts in the field and Alumni interactions are some of the unique features

of NIE.

xii

Sri Jayachamarajendra College of Engineering, Mysuru

Sri Jayachamarajendra College of Engineering (SJCE) in Mysuru was established in the year

1963 under the aegis of JSS Mahavidyapeetha. It has carved a niche for itself as a premier center

for Technical Education. Well-equipped and sophisticated laboratories, Library and sports facility, highly qualified and experienced faculty and staff members, well-designed college

campus are the reasons for its success. SJCE is an autonomous grant-in-aid institution under

Government of Karnataka, approved by University Grants Commission and accredited by

National Board of Accreditation. It is now a part of JSS Science & Technology University. As the institution plans towards national and international presence, SJCE promises to offer more and

more exciting opportunities for students, faculty and staff. SJCE features nationally recognized

faculty members who teach 31 academic programs (including MCA and MBA) at undergraduate

and postgraduate levels in emerging disciplines, participate in vital scientific research, using modern facilities and technologies with a focus on preparing technological leaders for the future.

It offers doctoral degrees in almost all established engineering disciplines. The institution’s

reputation for academic excellence in professionally oriented programmes attracts students from across the country and world. The faculty members of SJCE are noted for their distinguished

background, research and the personal attention they offer to students. Excellent placement

records, impressive interaction with industry and user system, active consultancy, always

energetic alumni network, keen interest in offering CEP courses and conducting workshops and conferences enhance the brand name of SJCE. This has enabled SJCE to be part of Technical

Education Quality Improvement Programme (TEQIP), a World Bank assisted project under

Government of India for the improvement of technical education in the country in all the three

phases and prestigious Global Initiative for Academic Networking (GIAN) in which a total of 28 programs were conducted by SJCE.

SJCE has progressed in improving the quality and quantity of students in general, and Masters &

Doctoral students in particular, improving collaboration with industry, increasing quantitative & improving qualitative research by faculty individually, jointly & collaboratively, developing

research interest among undergraduate students, improving the academic performance of weak

students, enhancing transition rate, improving employability of students through Finishing

Schools and improving institutional governance. Two of the main focuses of SJCE have been ‘Research’ and ‘Internationalization’.

xiii

A Brief look at the proceedings of RAGI 2020

Dr. H.S. Prasanna

Chairman RAGI-2020

Dr. S. Raviraj

Editor Proceedings RAGI-2020 Dr. S.K. Prasad

Organising Secretary RAGI-2020 &

Editor Proceedings RAGI-2020

It gives us immense pleasure that RAGI 2020, a technical extravaganza on ‘Recent Advances

in Geotechnics for Infrastructure’ is being conducted in a different style as a webinar in

14-17 May, 2020. The workshop is jointly organised by Association of Consulting Civil

Engineers (ACCE) Mysore Center, Indian Geotechnical Society (IGS), Bengaluru Chapter,

The National Institute of Engineering (NIE), Sri Jayachamarajendra College of Engineering

(SJCE) and Ramco Cements Ltd. This is the sixth effort alternatively organized at SJCE and

NIE. Earlier five editions were on yearly basis, and it has now been planned to organize

biennially. The previous editions, namely RAGI 2014 was held on 15 th March 2014 at SJCE,

RAGI 2015 was held on 25th April 2015 at NIE, RAGI 2016 was held on 7th May 2016 at

SJCE, RAGI 2017 was held at NIE on 25th March 2017 and RAGI 2018 was held at SJCE on

3rd March 2018. Though it was planned to conduct the workshop conventionally this time,

recent pandemic that has changed the life of every one across the globe has pushed us to look

for an innovative and effective way of reaching out to many professionals online through

webinar. The highlights of the online workshop include

Bringing together the stalwarts in the area of geotechnical engineering as resource

personnel under one platform,

Strengthening the industry-institute collaboration between two popular academic

institutions and important professional bodies through this national workshop on a topic

relevant to the construction industry, and

Focussing the training for more than 1000 professionals across the country representing

Academicians, Builders, Consultants, Developers, Engineers and Students from

government and private organisations.

We are extremely honoured and proud that renowned speakers, Dr. M.R. Madhav, Professor

Emeritus IIT Hyderabad, Dr. G.R. Dodagoudar, Professor of Civil Engineering at Indian

Institute of Technology Madras, Chennai, Er. I.V. Anirudhan, a busy geotechnical consultant

in Chennai and Er. P. Mohan Prasad, a very active soil consultant in Bengaluru have accepted

to be the resource personnel for the workshop and have sent their technical materials of their

lecture in time for publishing in the proceedings. All these speakers have contributed a lot in

their chosen fields and have performed very well in Civil Engineering arena exhibiting rich

experience in academics and in field. RAGI 2020 therefore can claim to possess a good blend

of academicians, researchers, consultants and field experts as resource personnel.

xiv

Infrastructure is the order of the day both globally and within our country. There has been

tremendous impetus on bridges, highways, railway, airports among transport sector, nuclear,

hydel, thermal, solar and wind energy power plants in energy sector, high tech hospitals,

speciality medical care units in health-care sector, primary and higher education schools in

education sector, factory units in industry sector in addition to the focus on urban

development. The focus of the present Indian government is on ‘Make in India’, ‘Digital

India’, ‘Clean India’ and ‘Skill India’ and further, to make our cities ‘Smart Cities ‘ and ‘Safe

Cities’. Hence, infrastructure, energy sector, health care, housing and development are of

primary importance. All of these require the construction of new and rehabilitation of existing

structures, and Civil Engineers are in greater demand these days than any time before. For

any structure to come up, geotechnical engineers are the first to arrive. With the increase in

complexity of superstructures and non-availability of good foundation soil, geotechnical

engineering has become even more challenging. Further, disasters and their effects on

mankind are on the increase. Last decade has witnessed many disasters, both man-made and

natural that have taken away many lives and caused huge economical loss. Even India had to

suffer from major disasters such as earthquake, flood, Tsunami, cyclone and several man-

made disasters causing huge human and economic loss. On the day of RAGI 2015, i.e. 25th

April 2015, there was huge earthquake of magnitude 7.3 in Nepal killing thousands of

citizens in Nepal and India. Most natural disasters result in subjecting dynamic loads to the

structures and hence to the foundations. Hence, another important priority of engineers is safe

construction that withstands all such disasters. It is therefore a challenge to civil engineers to

consider complex, expected and unexpected loading conditions. Finally, it is the foundation

soil that has to bear all these forces without undergoing failure or unprecedented deformation.

Geotechnical engineer has to gear up to these requirements also.

Considering these aspects, there is tremendous scope for geotechnical engineering related to

urban infrastructure especially deep excavations, tunnelling, reinforced earth and geotextile

concepts, and ground modification techniques. The topics covered in the proceedings include

the lecture materials of the four speakers in the areas of Geotechnical investigation, case

studies of geotechnical failure and piled – raft foundation.

The present situation of lockdown of entire world in general, India in particular has allowed

us to effectively use the time for enhanced learning, cultivating work from home culture and

connecting with people to develop and enhance professional skills in civil engineering.

We are very confident that the proceedings containing the lecture material from resource

personnel covering the topics mentioned above will be extremely useful to engineering

community and will create greater interest in these topics among researchers and take

geotechnical engineering to greater heights.

Dr. H.S. Prasanna

Chairman RAGI-2020 Professor of Civil Engineering

NIE, Mysuru

Dr. S. Raviraj Editor Proceedings RAGI-2020 Professor of Civil Engineering

SJCE, Mysuru

Dr. S.K. Prasad Organising Secretary RAGI-2020 & Editor Proceedings RAGI-2020 Former Professor of Civil Engg.

SJCE, Mysuru

xiv

PROCEEDINGS OF NATIONAL WORKSHOP ON

RECENT ADVANCES IN GEOTECHNICS FOR INFRASTRUCTURE RAGI – 2020

CONTENTS

Page

No.

MESSAGES

A1 President, Association of Consulting Civil Engineers (India), Benglauru i

A2 President, Indian Geotechnical Society, New Delhi ii

A3 Principal, The National Institute of Engineering, Mysuru iii

A4 Principal, Sri Jayachamarajendra College of Engineering, Mysuru iv

A5 Chairman, Association of Consulting Civil Engineers (I), Mysore Center v

A6 Chairman, Indian Geotechnical Society, Bengaluru Chapter vi

A7 Head of Civil Engg., The National Institute of Engineering vii

A8 Head of Civil Engg., Sri Jayachamarajendra College of Engineering viii

A9 About Association of Consulting Civil Engineers (I), Mysore Centre ix

A10 About Indian Geotechnical Society, Bengaluru Chapter x

A11 About The National Institute of Engineering xi

A12 About Sri Jayachamarajendra College of Engineering xii

A13 A Brief look at the proceedings of RAGI 2020 xiii

A14 Contents xiv

TECHNICAL PAPERS

B1 Madhav M.R. - Some Challenging Geotechnical Solutions 1

B2 Mohan Prasad P. - Some common misconceptions about

Geotechnical Investigations 8

B3 Anirudhan I.V. - Significance of Case Studies in Geotechnical

Engineering 11

B4 Dodagoudar G.R. - Materials, the environment and Piled raft

foundation 27

PROGRAMME DETAILS

C1 RAGI – 2020 Program Schedule 38

C2 RAGI – 2020 Brochure 39

C3 Details of Speakers 41

1

M.R. MADHAV

Professor Emeritus

IIT Hyderabad & JNTU Hyderabad

e-mail: madhavmr@gmail.com

Prof. M.R Madhav, Institute Fellow, IIT Kanpur, AICTE – INAE

Distinguished Visiting Professor, Visiting Professor, IIT Hyderabad &

Professor Emeritus, JNTU Hyderabad, Resource person, RGUKT and Advisor to several

organizations, is well known internationally as Researcher, Teacher and Consultant, has

contributed significantly to the practice of Geotechnical Engineering over the last five decades

and worked for several universities abroad – Australia, Canada, Japan, Belgium, UK, etc.. Prof.

Madhav’s research interest spans the whole gamut of Geotechnical Engineering. He has guided

more than 45 doctoral and several master’s theses and final year projects and has authored more

than 500 publications in refereed international and national journals and conferences.

Prof. Madhav is Fellow of Indian National Academy of Engineering, Indian

Geotechnical Society & Institution of Engineers (India), President, International Association

of Lowland Technology (2010-18), Vice President for Asia, International Society of Soil

Mechanics & Geotechnical Engineering (2005-09) recipient of Keucklemann, Prof. Mehra

Research and Pundit Jawaharlal Nehru Birth Centenary Research Awards, and Doctor of

Science of the Indian Institute of Science, Distinction in Engineering Technology from the

Central Board of Irrigation and Power, Bharat Ratna M Visweswaraya Award, Gopal Ranjan

Research Award of IIT, Roorkee, Indian Geotechnical Society – M S Jain award, Vishwakarma

Award for Academic Excellence from Construction Industry Development Council, Dinesh

Mohan Award from Indian Geotechnical Society, Distinguished Teacher award from IIT,

Kanpur, Distinguished Alumnus award from I.I.Sc., Bangalore among many.

2

SOME CHALLENGING GEOTECHNICAL SOLUTIONS

M.R. Madhav

AICTE-INAE Distinguished Visiting Professor

Visiting Prof., IIT & Professor Emeritus, JNTU, Hyderabad

e-mail: madhavmr@gmail.com

ABSTRACT The presentation covers some very interesting and challenging situations in the practice

of geotechnical engineering. Recent technologies have been used to overcome the challenges

in the form of using gabions for mitigation of coastal erosion, block faced 24.0 m and 40.0 m

high geosynthetic retaining structures to widen a ghat/hill road and construction of buildings

on super to very soft marine soils close to the coast.

INTRODUCTION

Challenges in Geotechnical Engineering come in very different forms since the

variability in ground conditions, is unpredictable nor decipherable. Often one has to think and

execute out of the box approaches to solve the problems faced at the site. The paper presents

few of these to illustrate the versatility of the challenges. They are:

1. Coastal erosion in the Gulf of Cambay off Gujarat Coast;

2. High Reinforced Soil Walls to Widen Ghat Road at Vijayawada; and

3. Construction of Buildings on Very Soft Ground on the East Coast.

GABIONS FOR PREVENTION OF COASTAL EROSION

North-Western coast of Gulf of Cambay (Fig. 1a) had been subject severe erosion as

both East and West coasts of the Indian subcontinent, with coast moving inward at the rate 5.0

to 10.0 m per year (Fig. 1b). The tide in the Gulf is of the order of 6.0 m and water velocity as

high as nearly 4.0 to 5.0 m/s.

Fig. 1(a). Gulf of Cambay and (b) Coastal Erosion

Fig. 2. Unsuccessful Attempts to Arrest Erosion

3

Conventional solutions such as sheet piling or contiguous piling were unsuccessful and

the problem had become extremely dangerous to several structures such as ship building yard,

oil wells, etc. close to the coast (Fig. 2). Hence it became necessary to think out of the box and

adopt gabion structures to ameliorate the problem.

Fig. 3. Gabions for Slope Protection and Rope Mattress Apron

The solution proposed consisted of PVC coated (to prevent corrosion) gabions for slope

protection and rope mattress apron 12.0 m long along the bed (Fig. 3). The slope was dressed

first, a geotextile laid over it over which sand bags were placed as cushion for the gabions to

rest. Relatively steep slope of 2H:1V was adopted. The apron was 12.0 m long in to Bay.

Gabions of 3.0 m width over-lap on the apron and provide additional basal resistance. 3.0 m

wide was provided at a height of 6.0 m. Pre-filled apron and the gabions had to be launched

underwater through barges and tied under with divers as the Gulf is never devoid of water.

Fig. 4(a). As Built April 2007 and (b) On May 2007

4

REINFORCED SOIL WALLS Sri Durga Malleswara Swamy Temple is located on the Indrakeeladri Hill in

Vijayawada, AP. The single lane ghat road, 3.5 m wide, was built circa 1940 (Fig. 5).

layout

MASTER PLAN OF GHAT ROAD

PROPOSED SITE FOR WIDENING

Fig. 5 Ghat Road Approach to and Initial Site condition at SDMS Temple Vijayawada

The pilgrim rush during annual festivals such as Vijaya Dasami, resulted in few

fatalities in 2006. It was initially decided to widen the road by blasting the hill. The proposal

dropped as the weak metamorphic rocks of the hills slop0es resulted in large over-break and

also because the vibrations from the blasting could damage the temple structures. Alternate

proposal was to build a 24 m high bridge from the valley side. Even this proposal was

considered due to lack of sufficient space and proximity to the river Krishna, etc.

Reinforced soil wall with block facing was accepted for several reasons including

economy and ease of construction without requiring deep foundations, etc.

COMPLETED TWO TIRED WALL VIEW FROM

KRISHNA RIVER

WIDENED GHAT ROAD AT ARUNDHAL

Fig. 6(a) Two-tiered Wall and (b) Widened Ghat Road

The two-tiered wall project (Fig. 6) was so successful that it was proposed to widen the

approach close to the temple to provide ample space for vehicle parking where the hill height

was 40.0 m (Fig. 7). Thus with recent technology of constructing reinforced soil walls, two of

the Asia’s if not in the world, highest retaining structures could be built with our indigenous

expertise. The construction of the second 40.0 m high wall posed several challenges during

construction because of variable ground conditions (both laterally and vertically), bonding

between hill slope and the backfill at the rear of the wall, unexpected rain from unseasonal

cyclone, large settlements and lateral movements (though permissible), carrying the material

to the top and dumping to the required level, etc.

5

Fig. 7. Four-Tiered 40.0 m High Block Faced Reinforced Soil wall

REINFORCED FOUNDATION BED OVER SOFT GROUND

Extremely soft soils are prevalent on both East and West coasts of Indian peninsula.

Typical profile from a site close to the coast near Machilipatnam in AP is shown in Fig. 8. The

strata consist of slightly desiccated soil in the top 2.0 to 3.0 m followed by dense sand overlying

very soft clay with SPT N values in the range of 0 to 5 to depths of 24.0 m. Site is water-logged

(Fig. 9).

Fig. 8. Typical Profile on the East Coast

6

Fig. 9. Site condition

Four-storied two bedroom apartments are to be built at this site. Conventional design

requires pile foundations driven to depths of 26.0 m or more to rest on stiff clay or in very

dense sand. The weight of the superstructure was reduced using precast or thin concrete panels

of 125 mm thickness and requiring relatively less bearing pressure. A thick, about 2.0 m,

reinforced foundation bed (RFB) consisting of geocells mattress with geogrids (Fig. 10) was

provided taking advantage of the desiccated crust and the dense sand layer underneath.

Fig. 9. Reinforced Foundation Bed

7

Fig. 11. Finished Project

EPILOGUE Most practitioners both structural and geotechnical, rely too much on scanty and ill

conducted investigations. However in some cases ground is much stronger and stiffer than

indicated by the above reports as has been established by our recent research.

0

2

4

6

8

10

12

14

16

18

20

0 0.2 0.4 0.6 0.8 1 1.2

Dep

th(m

)

Compression Index

Compression

Index(Insitu)

Compression

Index(Lab)

0

2

4

6

8

10

12

14

16

0 1 2 3 4 5 6

Dep

th(m

)

Cvr radial flow (m2/yr)

Cvr(in-situ)

Cvr(lab)

Fig. 12. Compressibility and Consolidation Properties In Situ and from Laboratory

Tests

Sadly and unfortunately the actual behaviour of the structures built are never monitored.

However if the response is observed has been carried out on some ground improvement

projects such as for the Suvarnabhumi International Airport and few others, the kind of

responses (Fig. 12) illustrate that compressibility is much smaller and the coefficient of

consolidation much larger than the values estimated from laboratory tests.

8

Er. P. MOHAN PRASAD

CEO, GEOMATRIX

Soil and Foundation Consultant, Bengaluru

Email: geomatrix@yahoo.com

Er. P. Mohan Prasad has been an active geotechnical

consultant for over two decades and heads the geotechnical firm

'Geomatrix' at Bengaluru. He has been a consultant to many organizations such as IOCL, IIM

Bengaluru, IIIT Bengaluru, KRIDL, KPTCL, SJI&R, Builders and property developers all

over Karnataka.

Er. Mohan Prasad obtained his bachelor degree in Civil Engineering from Bangalore

University and master degree in Geotechnical Engineering from Indian Institute of

Technology Bombay, Mumbai. He worked as a professor at Bangalore Institute of

Technology for ten years and was an extremely popular teacher motivating the students in the

area of Geotechnical Engineering. He has extensively worked in the areas of deep

excavations, foundations in difficult environment and ground improvement related to field

conditions.

9

SOME COMMON MISCONCEPTIONS ABOUT GEOTECHNICAL

INVESTIGATIONS

Er. P. Mohan Prasad

CEO, GEOMATRIX

Soil and Foundation Consultant, Bengaluru

Email: geomatrix@yahoo.com

The geotechnical investigation is essentially an interactive and collaborative exercise

between geotechnical and structural engineers. In most of the civil engineering problems

where there is an interface between soil and structural elements, the behavior of one is

influenced by the other and thus separating and dealing with each, disregarding the other

would be a mistake. Though geotechnical investigation is an essential exercise in the context

of slope stability analysis, design of earth retaining systems, ground improvement

techniques, borrow area soil testing, sub grade soil evaluation etc., its most important

relevance lies in foundation analysis and design and thus the focus will be in this context.

Generally the geotechnical investigation as practiced currently has come under cloud

of apprehension for many reasons which includes highly varied approaches, procedural

lapses, non-conformity with codal specifications etc. In this context it becomes very

important to build bridges with structural engineers who are the end users of geotechnical

investigations by highlighting and addressing some of the common misconceptions

prevailing and distorting this interactive exercise.

1. For any structure, light or massive, temporary or permanent, RCC or any other type,

geotechnical investigation in some reasonable measure is essential and thus intervention

of geotechnical engineers is inevitable - a fact which is not appreciated so well by some

structural engineers and architects.

2. The nature and extent of geotechnical investigation depends upon the site conditions, the

details of proposed structure etc., and thus it is better if left to the discretion of

geotechnical engineers, to plan and frame an appropriate geotechnical program.

3. The type of foundation and depth of foundation may be tentatively decided by the

structural engineers and architects, but finally it should be left to the discretion of

geotechnical engineers, as this issue is more involved factoring many aspects that gets

revealed only in the course of geotechnical investigation.

4. The ‘Allowable Bearing Pressure’ is not an unique value for a site or soil, as it also

depends upon the details of the proposed structure as much as the sub surface

conditions at the site and thus it is essential that structural engineers should be more

forthcoming in providing all the relevant and pertinent details to geotechnical engineer

to accomplish a more rational and rigorous foundation design.

5. The geotechnical engineers should be very mindful about collateral effects of the

excavation and construction of the sub structure and super structure on neighboring

structures and vice – versa, and thus geotechnical investigation and foundation design

should be made in this perspective.

10

6. The geotechnical investigation reports are legal documents as well, and thus it should

be very specific regarding all relevant aspects and it should be preserved carefully and

also in case, future extensions and modifications for the structure is envisaged.

7. Even if the site is all rocky, geotechnical investigation is necessary as infirmities in the

rock mass plays a crucial role in its capacity to support the proposed structure, and

which can be quantified only by the way of geotechnical investigation.

8. Expansive soils, highly organic soils and deep / loose / under consolidated ‘fills’

certainly pose serious challenges to the construction projects, but it can be tackled by

appropriate ground improvement techniques, special foundations and precautionary /

remedial measures.

9. It is a good and desirable practice for geotechnical engineers to visit the site after the

geotechnical investigation and when the ground is opened up for laying the foundation

concrete to ascertain the soil conditions all over the site at the recommended foundation

depths and compare weather it matches with what was encountered at the borehole

locations during investigation and it should be insisted on by the construction engineers.

In the light of above if necessary there should be no hesitation in seeking further

investigation or to revise the foundation recommendations.

10. It is very important for geotechnical engineers to look at the site as part of the general

area in which it is situated, rather than in isolation, as it can provide very important and

vital inputs in the assessment of sub soil at the site.

Hereby an attempt is made to close the gaps in our conception and open up communication

with all the stakeholders in the construction field and thus leading to a coherent,

comprehensive and rational geotechnical investigation.

11

ANIRUDHAN I. V.

CEO, Geotechnical Solutions

Chennai

e-mail: anirudhen@gmail.com

Er. I.V. Anirudhan is the CEO of a consultancy firm 'Geotechnical

Solutions' at Chennai and has carried out several geotechnical

investigation studies all over India and has substantial experience in the construction of bored

cast-in-situ piles, and driven cast-in-situ piles. He has designed and executed several ground

improvement programmes involving rammed and vibro stone columns, sand drains, PVD etc.

He has carried our several consultancy works for sewage treatment plants, water treatment

plants, effluent treatment plants, desalination plants, power plants, fertilizer plants etc. He is

presently a consultant to some of the leading consultancy firms and turnkey contractors.

Er. Anirudhan completed Graduation in Civil Engineering at Trichur, Calicut

University in 1979 and obtained masters in Geotechnical Engineering from IIT Kanpur in 1981.

He has published and presented technical papers in many Conferences and Seminars and has

written a manual on Lateritic soil and edited the ‘General Guidance for Geotechnical

Investigation’ by TC-04 of IGS.

Er. Anirudhan was Co-Editor of Indian Geotechnical Journal for four years, is the past

Chairman of Indian Geotechnical Society, Chennai Chapter, Member of Board of Studies in

Civil Engineering at Anna University, Chennai, Vice Chairman of Deep Foundations Institute

of India and Convener of TC-04 on Geotechnical Investigation among many.

12

SIGNIFICANCE OF CASE STUDIES IN GEOTECHNICAL ENGINEERING

Anirudhan I. V.

CEO, Geotechnical Solutions, Chennai

e-mail: anirudhen@gmail.com

ABSTRACT Sustained efforts by the practising engineers and the academia to present relevant case

studies from failures and success stories alike have immensely benefited the geotechnical

engineering practice in India. Such studies are the basis for developing theoretical formulations

and for improving the existing construction practices. Significance of case studies has increased

in India, and it has been one of the themes in seminars in India. There is always a need for well-

documented case studies as there is continuous development in the area. There are several case

histories reported in the literature that can be pursued further to provide useful information.

Such in-depth studies of existing case histories are necessary to highlight specific vital issues

that might otherwise have been overlooked. This paper highlights the importance of case

studies and present brief accounts of some cases related to the geotechnical investigation, piled

raft foundation, ground improvement techniques, uplift due to groundwater, foundations on

soft deposits, etc.

INTRODUCTION

The importance of Case Studies in the development of geotechnical engineering

practice is well understood in India and Case Studies have been one of the themes in almost all

the Geotechnical Conferences. Several conferences devoted explicitly to Case Studies in

Geotechnical Engineering [1, 2] have been organised. They provide beneficial information

about geotechnical practices in India. International conferences on Case Histories in

Geotechnical Engineering from by the University of Missouri Systems, Rolla also showcased

several case studies from India [3].

All these case studies are supposed to introduce something new to us or to tell us

whether we are on the right path or not. Unfortunately, significant numbers of the published

case studies either leave us confused or do not provide any advanced insight. Nevertheless, as

many as case studies, from trivial to very intense, in geotechnical engineering are to be

encouraged for the benefit of several important projects that are to come up. Also important is

the fact that several pieces of research were initiated from such case studies and produced

valuable guidelines. Several researchers attempted to use well-documented case histories for

modifying the theories or for developing approaches that are much closer to practice. The great

divide of theory and practice in the more complex geotechnical engineering problems shall

transform into a thin line.

Most practitioners shy away from publishing field data, especially from the failures,

that mar the opportunity of enthusiastic researchers in the realm of geotechnical engineering.

Even the publishing of successful stories is vital to make the users more confident and

optimistic. However, presenting and analysing failures in a detailed manner shall increase so

that the mistakes are not repeated.

This paper presents some cases in geotechnical engineering that may be of widespread

occurrence. Threadbare analysis of each case is not envisaged here as the purpose of this paper

is to highlight the significance of even smaller findings during the geotechnical engineering

13

practice. Case studies on a geotechnical investigation, pile-raft foundation, ground

improvement techniques, uplift due to groundwater, storage tank foundations, a foundation on

soft deposits and gabion facia using laterite blocks are presented.

GEOTECHNICAL INVESTIGATION AND ITS FOLLOW UP

Several cases of mismatch between the real sub-soil profile and the one provided in the

investigation report are brought out by several authors. Yet another scenario is the unexpected

variations in the subsoil conditions despite carefully executed geotechnical investigation. Few

such cases are presented here.

Weak Deposits due to Human Intervention

Full raft foundation resting over weathered disintegrated rock at about 3.50m below the

ground level was adopted for some high rise residential apartment blocks in south Chennai.

The foundation excavations revealed the expected sub-soil conditions in most of the area.

However, there were localised patches of poor soil conditions. The photograph in Figure 1

illustrates a very wet and dark spot over an area of about 100 sq metres.

Fig. 1. Dark and wet patch differentiating the

possibility of varying soil conditions Fig. 2. Excavation showing the presence of

dark grey medium stiff sandy clay

Photograph in Figure 2 shows the profile of excavation within this reach. Dark grey

sandy clay present for another 1.20m to 1.50m was to be replaced with well compacted gravelly

soil for improving the founding stratum. There were three such localised pockets in the same

project, and these were attributed to old irrigation wells of shallow depths that were closed long

back because of siltation and low recharge capacity. These wells were closed using the soil

excavated from the new wells and the top three to four meters did not show much difference

from the type of soil that existed in the surroundings. Detailed geotechnical investigation

comprising exploratory boreholes did not reveal these weak profiles, probably because of small

horizontal spread of these soft pockets.

Variations in Residual Deposits

Residual formation comprising clayey sand and weathered disintegrated rock followed

by the weathered rock at shallow depth often show unexpected changes. Foundation resting in

the weathered disintegrated rock was adopted for blocks of high rise buildings in another site

having similar geological settings as in the above case. Four exploratory boreholes distributed

in the plan area of one of the blocks and the foundation excavations in the respective regions

recorded highly weathered fractured rock as expected. 4.50m deep excavation was in progress

in this block during which highly varying subsoil conditions were noticed over a relatively

14

small area of about 150 sq meters. The excavation presented in Figure 3 illustrates the sub-

strata conditions and its variations in one-quarter of the total footprint of this block. Hard

granitic gneiss is present in an area of about 120 sq. m., while very stiff sandy clay is found

adjacent to this rocky area. Rest of the footprint recorded weathered fractured rock as revealed

during the investigation.

Figure 4 illustrates localised hard rock formation in the excavated area.

Fig. 3. Excavation showing the presence of

highly varying soil conditions

Fig. 4. Excavation showing localized hard

rock for an area of 120 sq. m

Even though the consultant recommended full raft, the initial designs were made

adopting individual column footings and stitched raft for the basement floor. A decision to

adopt a full raft foundation was later taken because of significant variations in the sub-strata

conditions within the same block. Another case of natural fluctuations follows.

Solution Cavities in Lateritic Soil Profile

Laterite formations often offer surprises, not very pleasant, despite extensive

investigations with exploratory boreholes. This case of presence of a large solution cavity

underlines the necessity of a more in-depth study of such deposits, preferably using geophysical

methods.

Roughly 2m diameter and 10m long solution cavity found in one of the construction

sites in North Kerala is shown in Figure 5. The cavity was sighted during 3.0m deep excavation

for a huge filtered water storage sump. The walls of the cavity were stunningly fresh without

any organic coating. The laterite that looked very strong from the appearance was, in fact, stiff

to very stiff sandy silty clay. More investigations were done using DCPT for shallow depths to

confirm that there were no such cavities within the construction area. However, the most

appropriate procedure for more information should have been seismic refraction study, as

explained in the next case study.

The cavity was filled with a mixture of the lateritic gravelly soil and roughly 8 per cent

cement to prepare the ground for supporting the sump.

Hard rock+7.20m

Weathered disintegrated rock

Overburden soil +5.80m

Overburden soil below +5.50m

15

Fig. 5. Solution cavities in lateritic formations

Mapping of Weathered Rock Profile

This case is with a profile comprising soft clay for varying thickness, followed by a

layer of dense residual sand and weathered rock. The exploratory boreholes revealed

significant variations in the elevation of weathered rock for about 150 metres. Figure 6 presents

the randomly selected profile of the weathered rock formation based on three boreholes at equal

distance. Since the investigation comprised only exploratory boreholes at specific intervals,

there was no way for confirming the uniformity in the sloping of weathered rock profile.

Exploratory boreholes also failed to establish the degree of weathering in the case of highly

weathered jointed/disintegrated rock. Since the proposed construction had plans for two

basements, presence of weathered rock at the lower basement floor level in some areas created

difficulties in deciding the type of foundation. More precise mapping of the weathered rock

elevation and the degree of weathering in the case of highly weathered rock stratum became

necessary in this case.

A more detailed survey was then carried out using seismic refraction procedure with 24

channel Geode seismic recorder with SGOS operating software. The vertical geophones of 14

Hz (24 Nos.) were used to receive the wavefields generated by the impact of a 10 kg

sledgehammer [5].

Figure 7 presents the seismic refraction profile along the same alignment, and it will

show a more defined weathered rock and rock profile.

Fig. 6. Subsoil stratification from three exploratory boreholes

16

The weathered disintegrated rock found between 8.0m and 12.5m in the mid-length of the

profile has better shear strength that is close to that of weathered fractured rock below. More

precise mapping by seismic refraction profiling helped the project owners to finalise a

foundation system comprising bored piles and full raft system for the high rise building with

two basements and twelve upper floors. However, the present seismic refraction study did not

try to evaluate more precise variations in the weathered rock formations. Such accurate

analyses could have helped the project in a better way.

Fig. 7. Subsoil stratification based on P wave velocity from seismic refraction studies [5]

Summary

Above four cases illustrate that even well-executed geotechnical investigations using

exploratory boreholes are not sometimes sufficient to establish variations in the profiles,

especially in the case of residual soil formations. There is a need for thorough follow up during

the project execution. Advanced investigation procedures like seismic refraction studies are

useful for mapping most of such variations in the sub-soil profile. The structural designer and

the project consultants who execute the project must have the support of competent

geotechnical engineer during the execution of geotechnical structures.

PILE FOUNDATIONS AS SETTLEMENT REDUCER

There are several successful cases of piled raft / pile assisted raft foundation for large

and high rise buildings, including that of the tallest structure in the world. One of the oldest

examples of pile foundations as settlement reducer was designed by Zeevaert [4] for La Azteca

office Building in Mexico City, constructed during 1954-55. A partly compensated foundation

system recorded a settlement about 200 mm at the end of construction, very close to the

predicted values. The corresponding dished settlement profile was on the expected lines with

about 30mm differential settlement over the base width. The anticipated foundation settlement

without friction piles was more than 500 mm.

Foundations of several large diameter storage tanks made of steel were designed and

constructed as pile assisted raft in one large fertiliser plant at Paradeep [6]. These tanks were

designed to tolerate settlement of 100mm to 120mm at the centre and roughly 75mm along the

periphery. 450mm diameter driven cast-in-situ piles of 10m to 12m length resting in medium

dense sand with cone resistance 50 to 60 kg/cm2 were used in the foundation system. There

were suggestions to provide long piles of 28m to 30m to limit the settlement to 25mm to 40mm,

but short piles were adopted as an optimal foundation design. A structure fully supported by

17

the driven cast-in-situ piles was initially designed. However, based on the performance of the

first three tanks, the number of piles was reduced, allowing about 20% load transferring to the

weak soil just below the raft foundation. Performance of 33m dia ammonia tanks (AT1 to 3)

during hydro testing is illustrated in terms of load settlement response in Figure 8. Figure 9

demonstrates the performance of 28m diameter phosphoric acid tanks (PAT1 to 5) during the

hydro testing and also during the final acid filling. It is essential to note that the soil-pile, soil-

raft and pile-raft interaction significantly reduced the difference between the settlement at the

centre and the periphery, which is a typical case of interaction model suggested by Katzenbach,

et al. [7].

Fig. 8. Load – settlement response of

Ammonia Tanks 1, 2 and 3 under hydro-

test [6]

Fig. 9. Load – settlement response of

Phosphoric Acid Tanks 1, 3, 4 and 5 under

hydro-test [6]

Advantage of the adopted foundation system is more evident from the comparison with

the performance of storage tanks supported on partly treated soil, as illustrated in Figure 10.

The fuel oil storage tanks (FT) were supported on ring wall foundations after replacing the top

3.0m weaker soil. The comparison is made for a maximum load of 10.0 t/m2 as the fuel oil

storage tanks were of 10m height.

Fig. 10. Settlement at center and periphery under hydro-test of tanks on pile foundations and

fuel oil tank on ring wall [6]

Summary

Even though the foundation, in this case, was not designed fully utilising the complex

soil-pile, soil-raft and pile-soil interaction in such systems, it established the efficacy of pile

assisted raft in settlement reduction. More rigorous analysis incorporating various forms of

soil-foundation interaction could have results more economical and technically optimal

foundation system.

0

20

40

60

80

100

120

140

160

180

P P(F) C P(F) P

Sett

lem

ent,

mm

Comparison of Settlement at app 10m Water Load

10.0m(AT1)

10.0m(AT2)

10.0m(AT3)

10.3m(PAT1)

10.3m(PAT2)

10.3m(PAT3)

10.0m(PAT4)

10.0m(PAT5)

10.0m(FT1)

10.0m(FT2)

0

20

40

60

80

100

120

0 2 4 6 8 10 12 14 16 18 20

Sett

lem

ent,

mm

Load in terms of Water Height, m

33m dia , 10000MT Ammonia Tanks 1, 2 and 3 - Hydrotest

AT1 (C) AT1 (P)

AT2 (C) AT2 (P)

AT3 (C) AT3 (P)

C and P represent centre and

periphery respectively

Acid loadingHydrotest limit

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20

Sett

lem

ent,

mm

Load in terms of Water Height, m

28m dia, 10000MT, Phosphoric Acid Tanks 1, 3, 4 and 5 - Hydrotest & Acid Loading

PAT1(C) PAT1(P)

PAT3(C) PAT3(P)

PAT4(C) PAT4(P)

PAT5(C) PAT5(P)

C and P represent centre and

periphery respectively

18

UPLIFT OF UNDERGROUND FIRE WATER SUMP

After two to three lifts of concreting totalling a wall height of 3.10m to 3.60m, one

8.50m x 22m size underground firewater sump ‘settled’ by about 400mm in one corner. There

was an instance of groundwater rise in the excavation after completing the second lift of

concrete. Southeast corner of the sump started moving down when the shuttering for the third

lift of concrete for the RC wall was placed in this corner. The space between the excavation

and the RC wall was immediately backfilled using excavated murrum type soil as the tank

experienced ‘settlement’ in one corner. Rains in the following days brought the water level in

the excavation close to the ground level. There was a concern as the tank ‘settled’ for about

400mm without any significant loading.

Site visit and perusal of elevation of the bottom slab, water levels in the sump, etc.

confirmed that the sump experienced an uplift, not ‘settlement’, of about 750mm in one corner

and almost zero uplift in the opposite corner. The additional lift of concrete for the RC wall

towards the South East corner caused the tilt. Figure 11 illustrates the elevation of the bottom

raft after the uplift and tilt.

Fig. 11. Elevation of base slab of the fire water sump after experiencing uplift.

The records of construction confirmed that the tank was more or less uniformly lifted

by about 0.40m during the first rise of the groundwater table. However, the third lift of

concreting without realising this uplift resulted tilting of the tank bringing down the corner

with the third lift of concrete to rest on the soil. This movement was misconstrued as

‘settlement’ as the levels were not cross-checked with the permanent benchmark. Backfilling

the excavation using murrum type soil after the uplift of the base resulted in non-uniform

migration of loose soil below the base slab. Subsequent efforts to bring down the tank to its

original level could not fully succeed as there was soil trapped below the base slab. Grouting

of the base slab for minor cracks developed due to unbalance loading and cement grouting

below the base slab to ensure proper seating of the base slab was executed to make use of the

sump. Additional dead load by way of extra soil cover over the roof slab of the sump was

necessary to ensure against uplift in future.

Summary

The case study reiterates the need for catering for the uplift forces due to shallow

groundwater table conditions, especially for underground sumps and structures with

basements. The chances of uplift are more during the construction stage than during the service

period as the dead weight available during construction is much smaller. Often the finished

structure is designed for uplift loads, but may not have adequate stability against uplift during

different stages during the construction.

19

GROUND IMPROVEMENT USING PVD ASSISTED PRELOADING FOR A

HOUSING PROJECT

Development of a housing colony in the backwaters of Tallassery, Kerala, after ground

improvement using pre-fabricated vertical drains, PVD, assisted preloading [8] triggered the

use of a similar system for different infrastructure projects in Kerala. The particular site was

low lying requiring about 2.00m thick filling to reach the finished ground level. The subsoil

comprised roughly 10m thick soft clay followed by stiff lateritic clay and weathered and sound

rock. The average load intensity from the G+1 villa type structures was about 4.0 t/m2. Roughly

7.5 t/m2 incremental load over the soft clay contributed from the construction as well as from

the fill could cause large consolidation settlement. After studying various options of the

foundation systems, ground improvement by PVD assisted preloading of the order of 4.0 t/m2

was adopted for limiting the building settlement within 40 to 50mm. Out of 2.0m filling

required for reaching the finished ground level, 1.20m thick fill was already in place. After

detailed settlement estimations and the assessment of improvement during preloading,

additional 3.80m high preload fill was decided. Out of this 3.80m fill, 0.80m thick fill was to

be retained to maintain the design finished ground level. 100mm size PVD at 900mm c/c

spacing was adopted.

The estimated compression of soft clay under the entire preload and the already existing

fill was 800mm to 900mm. About 90% consolidation settlement was expected during the

preloading period of 90 days. This settlement is roughly 800mm. It means that another 800mm

thick fill is to be retained from the total preload. Accordingly, about 2.20m thick fill is available

as real preload fill in the design, that can be moved to other areas. The recorded settlement was

680mm to 750mm during preloading and plan was to remove 2.20m thick fill to replace with

the structure load. Figure 12 illustrates the time settlement response under preload fill. The

observed settlement after 90 days was about 90% of the total expected settlement.

Fig. 12. Time Settlement response during preload fill of 3.80m [8]

However, there was re-thinking on the finished ground level because of anticipated

floods during heavy rains. The design finished ground level was thus revised, increasing it

further by 0.80m. This increase in the finished ground level reduced the real preloading height

to 1.40m totalling a load intensity of 2.70 t/m2 against the design preload of 4.00 t/m2.

Construction of two villas was however allowed redesigning the foundation as RCC strip raft

(instead of individual footings) since the expected settlement was 80mm to 130mm settlement

due to the deficiency in preloading. Systematic monitoring of two villas revealed that the

structures settled by 130mm to 140mm. Figure 13 presents the time settlement data for villa

42.

20

Fig. 13. Time Settlement response for Villa No: 42

The detailed back analysis confirmed that the increase in the settlement is due to the

deficiency of 1.30 t/m2 in the preloading. The lack of preloading is graphically represented in

Figures 14.

The preload thickness was revised for the remaining areas for 40 more villas, and the

rest of the villas experienced only 30mm to 40mm settlements.

Fig. 14. Deficiency in preloading that results undue settlement under structure load [7]

Summary

This case clearly illustrates the efficacy of ground improvement using PVD assisted

preloading procedure. It is necessary to accurately estimate the incremental load due to the fill

retained after the preloading and the structure load when the primary purpose of preloading is

settlement control.

TILTING OF STEEL STORAGE TANK ON RING WALL FOUNDATION OVER

SLOPING TERRAIN

One of the wet slop oil tanks at BPCL Kochi settled more than expected and tilted

during hydro test just under half of the full hydro test load. The tilt as well as the settlement

was alarming and was advised to suspend the hydro testing. The settlement under 50% of the

water load, i.e. @ 7.0m was 23mm in the northeast and 76mm in the south-west quarter. The

tank was unloaded, and the residual settlements were recorded. However, the tank settled and

tilted further even under reduced loads that suggested the commencement of a bearing capacity

failure. The tank was the completely emptied and the residual settlement was 22mm and

75mm, from 44mm and 107mm under 1/4th of the full hydro test load. The tank visibly tilted

towards the south west quarter. Out of plumb measurements also confirmed the tilt.

EXTRA LOAD FROM THE

REVISED FGL

SETTLEMENT

EXPECTED

ACTUAL

SETTLEMENT

SE

TT

LE

ME

NT

LOAD

REMOVED PRE-LOAD

DEFICIENCY IN PRE-LOAD

Pc

P0’

FILL TO BE LEFT OUT FOR

COMPENSATING SETTLEMENT

DESIGN PRE-LOAD

21

The 10.80m diameter and 13.90m height steel storage tank was supported on a ring wall

foundation resting in lateritic soil. The foundation was kept at a depth of 3.0m below the

finished ground level as the top 3.0m soil was filled up lateritic soil. The foundation conditions

looked uniform and did not suggest any reason for such behaviour of the tank. The estimated

settlement was of the order of 50mm to 70mm under the maximum load.

The site visit revealed that the tank is resting uphill with a very steep downward slope

in the south and south-west side. The flat ground beyond the ring wall was only 2.00m, and

then the ground dipped at a rate of 6 vertical to 1 horizontal. It became evident that the tank

base towards south side was about to experience bearing capacity failure in the absence of

adequate overburden and lateral confinement.

The tank pad area towards the south was supposed to be developed by compacted fill

supported by reinforced soil with gabion facia. The final dyke area shall extend towards the

south by about 11.0m from the tank periphery. This development work was expected to

provide adequate stability to the tank foundation, and the lack of it could cause instability to

the foundation.

The gabion supported filling work in the south was completed before proceeding with

the hydro-testing to the full height. Even though the filling towards the south side could have

provided stability under normal conditions, steel pipe piles were installed around the ring wall

foundation for about 1/3 circumference in the south side. This measure was expected to stop

the yielding of founding soil that initiated during the first phase of hydro testing.

The tank was hydro tested to its full height after the development of dyke area and treatment

with steel pipe piles. The summary of hydro test records is given in Table 1. Further settlement

of 19mm to 43mm was recorded under 13.4m water load, and the total settlement was 45mm

in the northeast while it was 118mm in the South West. Even though the rate of settlement

reduced significantly after the treatment, the tilt marginally increased. The slant measured

along the full height of 13.90m was 115mm, that is slightly more compared to the tilt estimated

proportionate to the base tilt.

Table 1. Settlement record of Wet Slop Oil Tank under hydro test

Date Load, water

column

Settlement, mm at the ring wall top

N NE E SE S SW W NW

16.11.2011 13.40m 17 18 33 36 39 39 38 27

25.11.2011 13.40m 19 18 33 36 39 39 41 30

2.12.2011 13.40m 19 23 29 40 43 43 43 31

10.12.2011 13.40m 19 23 29 40 43 43 43 31

17.12.2011 13.40m 19 23 29 40 43 43 43 31

05.01.2012 13.40m 19 23 29 40 43 43 43 31

30.01.2012 13.40m 19 23 29 40 43 43 43 31

Settlement during first stage 25 22 43 62 74 75 55 40

Cumulative settlement 44 45 72 102 117 118 98 71

The observed tilt was unexpected, and there were concerns about the structural stability

of the storage tank.

22

Many researchers have opined that the tank shell and base do not experience

considerable distress if the tilt is close to a planar tilt. However, more significant planar tilt can

make the tank oval resulting in undue distress in the shell and the roof. It was hence necessary

to confirm that the tilt was close to planar tilt and the out of planar differential settlement along

the wall is within the allowable limits that ensure the absence of undue distress. The settlement

data were analysed as suggested by Allen Marr, and the theoretical planar tilt and the deviation

from the theoretical planar tilt were determined as presented in Figure 15.

The observed settlement pattern is almost following the planar tilt. It was thus

concluded that the differential settlement of tank A under final load under the hydro test is

causing a planar tilt.

The maximum settlement occurs at 200.81 degrees with respect to North and the

maximum settlement at this point is 122.4mm. The minimum settlement is 45.8mm

diametrically opposite to the maximum settlement location. The maximum diametrical

differential settlement along planar tilt curve shown in Figure 15 is 122.2 – 45.8 = 78.4mm that

is over a diameter of 10.80m. The projected tilt over the full height of the tank (14.08m) is

computed as 78.4 x14.08÷10.8 = 102.2mm. This tilt was acceptable as the tank has a conical

fixed roof system with 550mm free board. The freeboard was, however, reduced to 430mm

after the tilt.

Fig. 15. Comparison of actual settlement with theoretical planar tilt of the wet slop oil tank base

The maximum out of the plane settlement and the out of the plane differential settlement

for the tank are 4.70mm and 6.80mm respectively in the south. Similar differential settlement

is observed at the observation point in the east. These differential settlements are less than that

can cause undue distress as per the provisions in API code 653.

Summary

Immediate measures to stop the hydro testing after recoding undue tilt and rate of

settlement under 30% of the design load prevented the bearing capacity failure of the wet slop

oil storage tank located very close to a very steep slope. The likelihood of failure was detected

by undue tilting and increased rate of settlement even though the settlement was not very large.

Comparison between the predicted settlements and the measured settlements during the hydro

test called for intervention that prevented a failure. The reason for such tilt was later attributed

0

20

40

60

80

100

120

140

0 45 90 135 180 225 270 315 360

Se

ttle

me

nt,

mm

Observation points

Settlement record of Tank ADeviation from planar tilt

ObservedSettlement

Max out of plane settlement = 4.7mm

23

to the commencement of bearing capacity failure in the absence of adequate overburden and

lateral confinement in one side of the ring wall foundation.

The dyke area of roughly 11m wide beyond the tank periphery was developed by

reinforced earth construction with gabion facia, and steel pipe piles were driven to stabilise the

soil immediately below the ring wall foundation before re-starting the hydro test. The tank

performed satisfactorily during this second phase of the hydro test.

BEHAVIOUR OF A FULL RAFT SUPPORTED BY SOFT CLAY

A two-storey institution building in south Madras, India, was constructed over a full

raft foundation below which soft clay of 7.5m thick existed. One year later an extension of the

same length supported on piles resting on the weathered rock was added. Shortly after this

construction, a differential settlement of 32mm between the new and old buildings was noticed.

Time settlement record for the building supported on full raft foundation for about five years

was then collected and concluded that a significant part of primary consolidation had occurred.

The observed settlement was 135mm.

However, the building on raft continued to settle and recorded little more than 450mm

apart from 100mm tilt in the next 25 years. A close perusal of the time settlement data showed

that the time-settlement response did not follow conventional primary consolidation pattern.

Possibility of undrained creep and plastic flow was reviewed.

Fig. 16. Time settlement data for building on raft foundation [9]

The differential settlement between the raft foundation and the structure on piles as on

23-12-2009 was little over 450mm as seen in Figure 17 a.

Acknowledging the fact that there were no records of the settlement occurred during

the first one and a half years, the actual settlement could be more than 500mm. The photograph

taken on 03-12-2012 presented in Figure 17 b shows practically no further relative movement

between these structures during these three years. The top parapet wall was repaired in the

recent past. The settlement towards the opposite side of the building (rear side) is more, and

both the photographs show a tilt towards the rear side. The settlement in the backside could be

about 520mm (more than 600 including the unrecorded settlement).

0

20

40

60

80

100

120

140

160

0 52 104 156 208 260 312 364

Settle

ment, m

m

Time, weeks

24

Fig. 17. Differential settlement between buildings on raft and pile foundations [9]

(a) as on 23-12-2009 and (b) as on 03-12-2012

Actual settlement records in the rear side are not available with the author. Based on

additional laboratory test data for the consolidation behaviour of the soft clay below the raft

and a detailed review of available observation data, it is concluded that the clay experienced

visco-plastic yield (undrained yield) apart from lateral squeezing and then primary and

secondary consolidation during the last 32 years [8]. The re-constructed time settlement plot of

this full raft foundation is presented in Figure 18.

Fig. 18. Hypothetical Creep and Consolidation in Time Scale [9]

Summary

The review highlights that the design of full raft foundation resting on soft plastic clay

cannot be treated as simple consolidation settlement problem. The increase in contact stress

levels due to the large difference in the stiffness of soil and the foundation is of utmost

importance.

Portion

on Raft

Portion

on Pile

Tilt

Portion on Raft

Portion on Pile

Tilt

25

GABION FASCIA USING LATERITE BLOCKS

About 4 metre high soil fill was to be retained for developing a service road in a water

treatment plant in North Kerala. The fill material available was lateritic murram type soil of

low to medium plasticity as the plant layout was developed mostly by cutting. Filling with a

stable slope was not attractive as the road was close to the boundary line of roughly 300m long

abutting private land. The owners did not want to reduce the area by providing a stable slope

of 1 vertical to 2 horizontal required in this heavy rainfall area.

Reinforced earth gravity wall with almost vertical face was designed to retain the earth

and to support the service road. Gabion fascia was adopted for retaining the soil between the

reinforcement.

Gabion fascia using plenty available laterite stone block filling was recommended.

Photograph in Figure 19 illustrates one stretch of such construction. The laterite blocks helped

in providing reasonably uniform fascia, as seen in the picture.

Failure of fascia was noticed in some stretches, as shown in Figure 20. It was found that

several stones were freshly cut and got crushed, resulting loosening of the gabion crates and

the resulting failure. The fresh-cut laterite stones are usually ‘soft’ and require ‘maturing’

before using in the construction. The usual procedure of maturing laterite stones is to expose

the stone to one or two seasons of wetting and drying, allowing it to dehydrate and hardened.

Fig. 19. Reinforced earth wall with gabion

fascia using laterite stone blocks Fig. 20. Crushing of ‘fresh’ laterite due to lack

of strength and loosening of gabion crates.

Unlike the conventional random rubble fill in the gabion boxes, laterite stone blocks

produced straight joints, especially after the blocks placed at the outer face. When the offset

between two vertical gabion boxes was more than half the width of individual laterite stone

block, the remaining stones were subjected to overstressing providing more chances for

crushing.

Summary

Use of alternative materials of construction requires careful study in terms of functional

qualities as well as the engineering qualities. Gabion fascia using laterite stone blocks as the

infill definitely provide an economical alternative to the conventional gabions with random

rubble packing infill. However, regular and continuous jointing of the machine cut laterite

stones create stress concentrations and unfavourable consequences as seen from this case study.

Also, the laterite stones need to be matured by hydration for attaining the required strength.

Crushed stones

26

CONCLUDING REMARKS

Some case studies on the geotechnical investigationS, pile-raft foundation, ground

improvement techniques, uplift due to groundwater, storage tank foundations, the performance

of foundation on soft deposits and gabion facia using laterite blocks are briefly presented.

Conclusions are offered as a summary at the end of each case.

Even though the brief narrations of these cases provide an overall picture of the problem

and solution, a more detailed treatment of each case helps the reader to understand better.

Some of the cases like pile assisted raft foundation resulting settlement reduction, PVD assisted

preloading for settlement reduction, and behaviour of full raft foundation on soft plastic clay

was subjected to detailed review and analysis as cited in the references.

REFERENCES

1. Ramesh H.N. and Santhaveerana Goud, (Eds) (2013), Two-day Workshop on Case

Histories and Research Avenues in Geotechnical Engineering, Department of Civil

Engineering, UVCE, Jnanabharathi, Bangalore University, Bangalore

2. Sivakumar Babu, G.L. and Sitharam, T.G. (Ed), (2005), National Conference on Case

Studies in Geotechnical Engineering, Bangalore, Interline Publishing.

3. Proceedings of the International conferences on case histories in geotechnical engineering

(1984-2013), Missouri University of Science and Technology.

4. Boominathan A. (2012), ‘Report on Seismic Refraction Tests Carried Out at the 20 Storey

Residential Building Project Site, Kottivakkam (Chennai).

5. Zeevart, L. (1957), ‘Compensated Friction Pile Foundation to Reduce the Settlement of

Buildings on the highly compressible Volcanic Clay of Mexico City’, Proc. 4th Int. Conf.

SM & FE, London, (2) 81-86.

6. Anirudhan I.V. and Balakumar V (2010), Pile Foundation as Settlement Reducer for Large

MS Storage Tanks, Proc. Indian Geotechnical Conference 2010, Mumbai.

7. Katzenbach R., Arslan V. and Moorman, Ch. (2000), ‘Piled Raft Foundation Projects in

Germany’, Design Application of Raft Foundations, (Ed.) J. A. Hemsley, Thomas Telford,

London, 323 – 391.

8. Anirudhan I.V (2009), ‘Characterisation of Distress and Some Cases’, Proc. of the National

workshop on Forensic Geotechnical Engineering. Department of Civil Engineering IISc.

Bangalore.

9. Anirudhan, I.V. and Ramaswamy, S.V. (2013) ‘Revisiting a Full Raft Foundation

Constructed on Soft Clay’, Proc., TC 207 Workshop on Soil-Structure Interaction and

Retaining Walls, Paris, France, September 2013, 38 – 50

27

Dr. G. R. DODAGOUDAR

Professor of Civil Engineering,

IIT Madras, Chennai 600036

e-mail: goudar@iitm.ac.in

Prof. G.R. Dodagoudar is a professor at Indian Institute of

Technology Madras, Chennai since 2002. He obtained Diploma in

Civil Engineering in 1988, Bachelor degree in Civil Engineering

from Basaveswara College of Engineering, Bagalkote in 1992,

Master degree in Geotechnical Engineering from Indian Institute of Technology Bombay,

Mumbai in 1995 and Doctoral degree also from Indian institute of Technology Bombay,

Mumbai with specialization in Geotechnical Engineering in 2001.

Prof. Dodagoudar has an experience of one year in industry and experience of eighteen

years in Research and Teaching. He has guided 14 Ph.D. Students, 7 M.S students and 20

M.Tech students so far and is presently guiding 9 Ph.D. students and one M.S student. He has

published 59 papers in international journals and 42 papers in national journals and has

presented more than 120 papers in proceedings of conferences. He has written one book and

two monographs. He has handled 15 research projects worth over Rs. 16 Crores and

consultancy worth over Rs. 2 Crores numbering more than 50.

Prof. Dodagoudar’s research interests include non-linear finite element analysis,

centrifuge modeling, earthquake geotechnical engineering and ground improvement

techniques. He is very active in continuing education programs, and delivers lectures and

motivating talks to students, academicians and working professionals across the country.

28

MATERIALS, THE ENVIRONMENT AND PILED-RAFT FOUNDATIONS

G. R. Dodagoudar

Department of Civil Engineering

Indian Institute of Technology Madras, Chennai 600 036, India.

e-mail: goudar@iitm.ac.in

ABSTRACT

Scarcity of land in urban area has forced the city developers to expand the cities in

vertical direction. As a consequence, a number of high-rise buildings have come up in recent

times in most of the cities in India and elsewhere. Mostly these high-rise building are located

in major cities of India like Mumbai, Delhi, Chennai, Bangalore, etc. Piled-raft foundations are

economical solutions for foundations of these structures. Combined piled-raft foundation

(CPRF) is a geotechnical composite construction that combines the bearing effect of both

foundation elements - raft and pile, by taking into account the interaction between the

foundation elements and the subsoil. The foundations of high-rise buildings are subjected to

vertical, lateral and overturning forces. These foundations need to be designed based on the

consideration of soil-structure interaction taking into the load transfer from the raft to the soil.

The load shared by raft varies from 20 to 60% as per the spacing of piles. In order to address

the issues associated with the soil-structure interaction, a numerical technique such as finite

element modelling is a must for the analysis of piled-raft foundations.

This study outlines the materials and the environment: the eco-aspects of their

production, their use, and their disposal at end of life and interaction aspects initially using a

raft alone, a single pile alone and a single pile-raft as foundation elements before attempting to

address the interaction issues of the piled-raft foundations. It also highlights ways to choose

and design with materials in ways that minimize the impact they have on the environment. As

responsible Civil engineers and scientists, we should try to understand the nature of the problem

— it is not simple — and to explore what, constructively, can be done about it. Later on,

detailed finite element simulations have been carried out for different piled-raft configurations

used for the high-rise buildings. A few case study examples have been attempted to highlight

the practical applicability and suitability of the combined piled-raft foundations (CPRFs) for

high-rise buildings within the framework of materials usage and the environment. Based on the

results of finite element analysis of the piled-raft foundations it is noted that the pile-raft

foundations are recognized as an economical and effective foundation system for high-rise

buildings. The piled-raft foundations require lesser number of piles for the stability and safety

of foundations thereby saving a lot of cement utilization during construction of these

foundations. It is also concluded that the raft is able to provide a reasonable measure of both

the stiffness and load resistance in a combined pied-raft foundation system.

1. INTRODUCTION

The beneficial effects of piled-raft foundation have attracted the foundation engineers

to design combined piled-raft foundations (CPRFs) for tall and super-tall buildings. The

combined piled-raft foundation (CPRF) transmits the load to deeper layer of soil and the

settlement is less compared to the raft foundation. The CPRF is a geotechnical composite

construction that combines the bearing effect of both foundation elements - raft and pile, by

taking into account the interaction between the foundation elements and the subsoil. The

foundation for tall building are subjected to vertical, lateral and overturning forces. The load

of superstructure is shared by raft and piles. In CPRF, the raft is able to provide a reasonable

measure of both the stiffness and load resistance.

29

Between the geotechnical design parameters 'bearing capacity' and 'settlement' which

are independent, if the design just satisfies bearing capacity, settlement will be over satisfied

(i.e., settlement less than permissible) and vice versa, if the design satisfies the settlement,

bearing capacity will be over satisfied. In either case the design is not optimum, which is

possible only in rare instance when both the requirements are optimally and simultaneously

satisfied, i.e., the factor of safety against the bearing capacity failure is at the minimum

stipulated values and settlement is just equal to permissible value. The above points to the need

for exploring methods by which the design can be made optimum. For example, in the case of

raft in sand, the question is whether it should be possible for us to design the raft satisfying

bearing capacity and look for extraneous means to control settlement which would otherwise

be excessive. One such solution available is to use piles in conjunction with the raft, the

function of piles being merely to control the settlement. Such a system is called 'piled-raft'. In

situations where a raft foundation alone does not satisfy the design requirements, it may be

possible to enhance the performance of the raft by addition of piles. The use of a limited number

of piles, strategically located, may improve both the ultimate load capacity and the settlement

and differential settlement performance of raft (Poulos, 2001).

There are different geometrical and mechanical properties that affect the total and

differential settlements of the CPRF such as the loading condition, shape and size of the raft,

diameter and length of the piles, number of piles, pile spacing, relative stiffness between the

raft and subsoil, and the pile arrangement scheme. These properties have to be considered in

the analysis and design of CPRFs. The behaviour of piled rafts is determined by complex soil-

structure interaction (SSI) effects, and an understanding of these effects is indispensable for

the reliable design of such foundations. Previous researchers have analyzed the CPRFs in two-

dimensional (2D) plane (Wulandaria and Tjandra, 2015; Noh et al., 2008) which may not give

accurate results. Three-dimensional (3D) finite element (FE) and finite difference (FD)

analyses are needed in order to study the interaction between the soil and CPRF system

effectively. These numerical methods are very useful in considering complex geometries and

different kinds of soil profiles compared to the field and model tests. Therefore, the CPRFs are

analyzed using finite element method (FEM) and finite difference method (FDM). Due to the

3D nature of the CPRF system and complexity of the SSI effects, calculation procedures for

piled-rafts are based on the above analyses, wherein the soil medium is modelled using

advanced constitutive relations. There are a few efforts in regard to the modelling of interface

between the raft and soil and, pile and soil using the advanced stress-strain relations. The 3D

numerical analyses results are more reliable in the case of CPRFs because they represent SSI

effects realistically. In CPRFs, the piles are provided only in the central area of the flexible raft

to achieve minimal differential settlement (Randolph, 1994; Poulos, 2017). This concept has

been verified through a set of centrifuge model tests (Horikoshi and Randolph, 1996). There

are some efforts made in regard to the usage of softwares such as ABAQUS, FLAC 3D and

PLAXIS for modelling and analysis of CPRFs in the literature. The solutions obtained by these

programs retain the essential aspects of interaction of the CPRFs through the soil continuum,

thereby providing a better representation of the problem.

2. OVERVIEW OF THE STATE-OF-ART

Design of tall building foundations involves the consideration of several aspects which

require input from both the geotechnical and structural engineers. The structural engineers are

responsible for the assessment of loads applied to the foundation, while the geotechnical

engineers focus on the foundation resistance and movements arising from the applied loads. In

this section, an attempt has been made to present the state-of-the-art review of literature related

to the topic of the present study on the following headings:

Load transfer mechanism in CPRF

Interactions in piled-raft foundation

30

Numerical modelling of soil structure interface

Static SSI analysis: A review

2.1 Load Transfer Mechanism in CPRF

The foundation should be designed such a way that the structure-foundation system is

stable, and safety is ensured under all forms of loading. The load from the superstructure is

transferred to the soil through the elements of CPRF. The soil, in turn offers a resistance to the

CPRF through the raft and piles. The total characteristic resistance applied by the soil on the

CPRF, Rtot,k (s) depends on the settlement 's' of the foundation and consists of the sum of the

characteristic pile resistances, , ,

1

( )m

pile k j

j

R s

and the characteristic raft (base) resistance, Rraft,k

(s) as shown in Figure 1. The base resistance results from the integration of the settlement

dependent contact pressure, σ (s, x, y) in the raft plan area.

The resistances offered by the pile component and raft, and the total resistance are given

by

, , , , , ,( ) ( ) ( )pile k j b k j s k jR s R s R s (2.1)

, ( ) ( , , )raft kR s s x y dxdy (2.2)

, , , ,

1

( ) ( ) ( )m

tot k pile k j raft k

j

R s R s R s

(2.3)

The load bearing behaviour of the CPRF is characterized by pile-raft coefficient αpr, which is

defined by the ratio between the sum of the pile resistances, , ,

1

( )m

pile k j

j

R s

and the total

resistance, Rtot,k (s) as

, ,

1

,

( )

( )

m

pile k j

j

pr

tot k

R s

R s

(2.4)

The pile-raft coefficient varies between αpr = 0 (raft foundation) and αpr = 1 (pile

foundation).

Fig. 1. CPRF depicting the pile and raft resistances (Katzenbach et al., 2000)

31

2.2 Interactions in Piled-Raft Foundation

The prerequisite for a safe design of CPRF is the realistic modelling of the interactions

between the superstructure, the foundation elements and the subsoil. This requires the use of a

computational model which is able to simulate the interactions determining the bearing

behaviour of the CPRF in a reliable and realistic way. The interactions between the piles, raft

and soil influence the behaviour of the CPRF and for prediction of the response of the CPRF

subjected to different loading, interaction factors have been used. There are four basic

interactions: pile-soil interaction, pile-pile interaction, raft-soil interaction and pile-raft

interaction, as shown in Figure 2. The pile-soil interaction is defined as the additional

settlement of a pile caused by an adjacent loaded pile, and the pile-raft interaction is defined as

superposing the displacement fields of a raft caused by a pile supporting the raft.

Fig. 2. Interactions in CPRF (Katzenbach et al., 2000)

Poulos and Davis (1980) proposed an approach for obtaining the pile-pile interaction

factor. Authors considered a pair of vertical piles embedded in a horizontally layered soil. The

formulation is based on the additional settlement of a pile under the interaction of the other

piles. Poulos (1989) proposed another approach that can be used for calculating the additional

settlement of a pile caused by a pile group surrounding it by superposing additional settlement

caused by each pile. Clancy and Randolph (1993) developed the interaction factor of a pile to

a raft, and is calculated based on the additional settlement of a circular rigid raft caused by its

supporting pile. This formulation, however, does not consider the change in soil stiffness along

the pile. Randolph (1994) proposed a modified version of the above formulation by considering

the stiffness of soil at the pile head and the pile tip and along the pile shaft.

2.3 Numerical Modelling of Soil Structure Interface

The modelling of contact surfaces using FE simulations have been developed in

geotechnical engineering. Most of the geotechnical problems attempted so far have used the

existing 3D constitutive soil models for representing the interfaces in FE models. The

consideration of interfaces into numerical analysis is often made by the use of simplified Mohr-

Coulomb friction laws, and the same is implemented widely in geotechnical engineering using

the master and slave concept.

Majority of the interface models developed in the geotechnical engineering have used

the elastoplastic framework. The Mohr-Coulomb friction is the most frequently used interface

model. The general form of the constitutive interface model is expressed as

( )f (2.5)

where is the stress tensor and is the strain tensor. For evaluating the stress tensor, the

following are required:

32

1. A yield criterion to distinguish between elastic and plastic behaviour. For interface models,

the yield criterion is used to estimate stick behaviour.

2. A plastic potential to describe the evolution of the yield surface.

3. A hardening and/or softening rule.

4. A compliance tensor, which governs the adhesion behaviour.

Mohr-Coulomb model

The Mohr-Coulomb friction law is the most widely used interface constitutive model.

This elastoplastic model combines linear elastic behaviour with plastic behaviour. The

constitutive equation for the Mohr-Coulomb model is given as

( )e e e p

t D u D u u (2.6)

where t is the rate of traction. The elastic constitutive matrix De is given by

0

0

e

i

GD

E

(2.7)

The shear modulus G and the constrained modulus Ei are expressed as

2(1 )

i

p

EG

v

;

12

1 2

p

i

p

vE G

v

(2.8)

where p is the Poisson's ratio. The constitutive equation for the interface yield function is

expressed as

tann if c (2.9)

where f is the yield function, is the shear stress, i is the friction angle at the interface, n

is the normal stress acting on the interface and c is the adhesion at the interface. The Mohr-

Coulomb model is a classical elastoplastic model, which is most often used in finite element

calculations.

2.4 Static SSI Analysis: A review

The existing methods for static analysis of piled raft foundations can be divided into

three groups:

(i) Simplified computational methods: These computational methods include simplification

in modelling of soil profile and loading on raft foundation with an equivalent single pile

(Davis and Poulos, 1972; Randolph, 1994; Burland, 1995).

(ii) Approximate computer based methods: (i) Strip on Springs Method in which the

shallow foundation is assumed to lie on springs which are representative of soil stiffness

like strip footing (Poulos, 1991). (ii) Plate on Springs Method in which the shallow

foundation is modelled as an elastic plate and piles as springs. In the previous studies using

the first method, some components of interaction were neglected thus the stiffness values

were very high (Clancy and Randolph, 1993; Poulos, 1994).

33

(iii) More rigorous computerized methods: These methods basically use rigorous FE and FD

analyses for the prediction of load-settlement response of the piled-raft foundations. The

softwares such as ABAQUS, FLAC, PLAXIS etc. are used in the analysis of CPRFs.

In the conventional design of piled foundations, the required number of piles is decided

assuming that all loads must be carried by the piles, ignoring any contribution from the raft or

the pile cap, even though the competent soil conditions may exist beneath the raft. This

conservative approach appears to be due to limited understanding of the interactions of the pile

group and raft with the soil, and the scarcity of validated methods of analysis for this complex

3D problem. In this section, a few of the publications related to static SSI analysis of the CPRFs

are reviewed and presented.

Clancy and Randolph (1993) developed a numerical method which was based on method of

hybrid modelling that combines the finite element modelling for the structural elements of the

piled-raft foundation and analytical solutions for modelling the response of soil. Ta and Small

(1996) have developed a method based on finite layer approach in which stresses and

displacements are often expressed in terms of their Fourier transforms. The raft is treated as a

thin elastic plate and is modelled using the FEM. It is found that the load sharing between the

piles in piled raft system was influenced by the thickness and stiffness of soil layer. This

method was modified by Small and Zhang (2002) by assuming the forces (horizontal and

vertical) between the piles and layered soil as a series of ring loads applied to nodes along the

pile shaft. This method was able to reduce the computational time required for the analysis.

Poulos (2001) suggested a three stage analytical design of CPRF which includes a detailed

analysis part for the settlement of the CPRF. Author emphasized on the importance of selecting

strategic locations for piles in the raft, which can optimize the design. The author also proposed

that increasing the number of piles, which is beneficial for serviceability requirements, does

not always produce the best foundation performance, and that there is an upper limit to the

number of piles, beyond which very little additional benefit is obtained.

Kim et al. (2001) have mentioned about the importance of pile arrangement for minimizing

the differential settlement. It is stated that the differential settlement of a CPRF depends on the

load type (i.e., a uniform distributed loads, line loads and concentrated loads). For practical

design, Messeturm tower in Frankfurt which was built on the CPRF used more piles near the

edges of the raft at the diaphragm positions (Katzenbach et al., 2005). Nguyen et al. (2013)

also presented the feasibility of a fairly optimal pile arrangement scheme for reducing the total

and differential settlements of the CPRF. The piled-raft was modelled in Plaxis 3D and results

of the same are compared with centrifuge results.

Lee et al. (2010) studied the three-dimensional behaviour of a piled-raft on soft clay using the

FEM. The analysis includes a pile soil slip interface model. Based on the results, the effect of

pile soil slip on the behaviour of CPRF was investigated. Furthermore, the proportion of load

shared between the raft and piles at the ultimate state was evaluated. The relationship between

the settlement and overall factor of safety was also evaluated. The results show that the use of

a limited number of piles, strategically located, might improve both the bearing capacity and

settlement performance of the raft.

Mu et al. (2016) proposed a hybrid approach for the analysis of CPRF subjected to a

combination of vertical load, horizontal load and moment in layered soils. The proposed

method comprehensively accounts for SSI effects. Authors used the shear displacement method

and elastic foundation beam method to calculate the vertical and horizontal responses of the

single pile, respectively. The same approach is later extended for the pile group. The results

34

obtained from the proposed method for the CPRF in layered soils are found to be in good

agreement with those obtained from the more rigorous FE analysis and theory of elasticity.

Lee and Moon (2017) developed an approximate hybrid method of analysis for practical

design of piled-raft foundations considering interactions between the pile and soil, raft and soil,

pile and pile, and raft and pile. The results of the study are compared with that of the 3D

nonlinear FE and approximate linear analyses for the example problem of a piled-raft

foundation in multi-layered soil. A computer program is also developed for the proposed

approximate method that can estimate the nonlinear behaviour of the piled-raft adequately.

3. DESIGN PHILOSOPHY OF CPRF

Super-tall buildings in excess of 300 m in height are presenting new challenges to

structural and geotechnical engineers. Design of foundations for these buildings requires the

state-of-the-art methods. In this regard, the CPRF provides an economical and rational

foundation alternative for high-rise buildings. Under coupled multidirectional loading, load

shared between the raft and piles enhances the effectiveness of the CPRF. This results in

smaller total and differential settlements with a reduced number of piles in the CPRF as

compared to the pile groups (Poulos, 2001; Mu et al., 2016). The CPRF requires piles to

decrease the settlement of structures, thereby improving the performance of the geologic

medium in providing the proper foundation support. In case of raft foundation, to take full load

a very thick raft is provided which increases the cost and settlement of the structure. In case of

piled-raft foundation, the load is distributed between the raft and piles depending on their

stiffnesses. It is of immense importance for analysis and design purposes to understand the

load-displacement responses of the CPRFs in clays, medium and dense sands subjected to static

and seismic loads.

There are commonly three broad stages in foundation design (Poulos, 2017):

1. A preliminary design, which provides an initial basis for the development of

foundation concepts and costing.

2. A detailed design stage, in which the selected foundation concept is analysed and

progressive refinements are made to the layout and details of the foundation

system. This stage is desirably undertaken collaboratively with the structural

designer, as the structure and the foundation act as an interactive system.

3. A final design phase, in which both the analysis and the parameters employed in

the analysis are finalized.

It should be noted that the geotechnical parameters used for each stage may change as

more knowledge of the ground conditions, and the results of in situ and laboratory testing

become available. The parameters for the final design stage should also incorporate the results

of foundation load tests. There are many design issues and criteria need to be addressed in the

design of foundations for high-rise buildings. If any of the design requirements are not satisfied,

then the design has to be modified accordingly to increase the strength of the overall system or

of those components of the system that do not satisfy the criteria. The load combinations, which

include several ultimate limit state combinations and serviceability combinations incorporating

long-term and short-term loadings, should also be considered for the safe design of CPRFs.

Many design philosophies are in use for the design of CPRFs. Figure 3 depicts the load-

settlement curves for piled-rafts according to various design philosophies (Poulos, 1981). The

preliminary stage of design can generally be undertaken with relatively simple and straight-

forward techniques to assess both the ultimate capacity and overall settlement performance.

However, for the detailed and final design stages, more refined techniques are generally

required.

35

Fig. 3. Load-settlement curves for piled-rafts according to various design philosophies

The behavior of piled-raft foundation depends on:

1. type of soil

2. loading intensity and distribution of load on raft

3. soft soil layers

4. soil behavior for numerical analysis (linear or non-linear)

5. flexibility of raft

6. end bearing condition (floating, compensated, end bearing)

7. pile diameter to raft thickness ratio

8. embedment of raft

9. pile spacing

10. the seismicity of region

11. topography (sloping ground, sloping founding layer)

12. the excavation adjacent to foundation

13. soil-structure interaction

The above factor should be taken into account while designing CPRFs for high-rise

buildings.

4. CONCLUDING REMARKS

The past two decades have seen a remarkable increase in the rate of construction of

super-tall buildings elsewhere in the world. In the assessment of a geotechnical model and the

associated parameters for foundation design, it is first necessary to review the overall geology

of the site and identify any geological features that may influence the design and performance

of the foundations. The in situ and laboratory tests are desirably supplemented with a program

of instrumented vertical and lateral load testing of prototype piles to allow calibration of the

foundation design parameters and hence to better predict the foundation performance under

loading.

It should be noted that the soil stiffness values are not unique values but will vary,

depending on whether long-term values are required (for long-term settlement estimates) or

short-term values are required (for dynamic response to wind and seismic forces). For dynamic

36

response of the structure-foundation system, an estimate of the internal damping of the soil is

also required, as it may provide the main source of damping. Moreover, the soil stiffness values

will generally vary with applied stress or strain level and will tend to decrease as either the

stress or strain level increases.

Conventional triaxial testing is of limited value for assessing design parameters for pile

foundations, as the method of stress application does not reflect the way in which load transfer

occurs from the piles to the surrounding soil. However, the cyclic triaxial testing may be useful

in providing an indication of the degradation effects on the stiffness/strength properties of the

foundation ground material due to cyclic loading. More sophisticated stress path testing can

provide stiffness parameters over a range of stress appropriate to the foundation system, and

can be used to compare with values from other means of assessment. For application to routine

design, allowance must be made for the reduction in the shear modulus because of the relatively

large strain levels that are relevant to foundations under normal serviceability conditions.

It is emphasized that the geotechnical parameters used for each stage may change as

knowledge of the ground conditions and the results of in situ and laboratory testing become

available. The parameters for the final design stage should desirably incorporate the results of

foundation load tests. Fairly a good understanding has been achieved with regard to how the

piled foundations interact with soils using the numerical simulations and experimental

investigations. In the case of CPRFs, the raft is allowed to significantly contribute to transfer

the load directly to the soil. In comparison to shallow foundations, piled-rafts effectively reduce

maximum and differential settlements, thereby minimizing the potential risk of tilt of the new

buildings. In urban environments, these positive effects also help to guarantee the stability and

serviceability of structures adjacent to the new buildings.

The application of the observational method is an important aspect for the successful

design and construction of CPRFs. During the construction of the CPRF, an autonomous

quality-control system is required, working independently of the contractor. A geotechnical

expert on site should ensure that pile construction is carried out in accordance with the

specifications defined in the foundation design. An important aspect of the independent quality

assurance on site is to ensure that the soil surface at foundation level is carefully prepared so

that subsequent raft contact pressures can be fully mobilized.

5. REFERENCES

1. Burland, J. B. (1995). Piles as settlement reducers, Proceedings of 19th Convention Naz. di

Geotecnica, Pavia, 2, 21-34.

2. Clancy, P. and M. F. Randolph (1993). Analysis and design of piled raft foundation,

International Journal for Numerical and Analytical Methods in Geomechanics, 17, 849-

869.

3. Davis, E. H. and H. G. Poulos (1972). The analysis of pile raft systems, Australian

Geomechanics Journal, G1, 1, 21-27.

4. Horikoshi, K. and M. F. Randolph (1996). Centrifuge modelling of piled raft foundations

on clay, Geotechnique, 46, 4, 741-752.

5. Katzenbach, R., U. Arslan, and C. Moormann (2000). Piled raft foundation projects in

Germany. pp. 323-391. In J. A. Hemsley (ed.) Design applications of raft foundations.

Thomas Telford, London.

6. Katzenbach, R., G. Bachmann, G. B. Mekasha, and H. Ramm (2005). Combined pile raft

foundations (CPRF): An appropriate solution for the foundations of high-rise buildings,

Slovak Journal of Civil Engineering, 13, 19-29.

37

7. Kim, K. N., S. H. Lee, K. S. Kim, C. K. Chung, M. M. Kim, and H. S. Lee (2001). Optimal

pile arrangement for minimizing differential settlements in piled raft foundations,

Computers and Geotechnics, 28, 235-253.

8. Lee, J. H., Y. H. Kim, and S. S. Jeong (2010). Three dimensional analysis of bearing

behaviour of piled raft on soft clay, Computers and Geotechnics, 37, 103-114.

9. Lee, S. and J. S. Moon (2017). Effect of interactions between piled raft components and

soil on behavior of piled raft foundation, KSCE Journal of Civil Engineering, 21, 1, 243-

252.

10. Mu, L., Q. Chen, M. Huang, and S. Basack (2016). Hybrid approach for rigid piled-raft

foundations subjected to coupled loads in layered soils, International Journal of

Geomechanics, 122, 1-15.

11. Noh, E., Y, M. Huang, C. Surarak, R. Adamec, and A. S. Balasubramaniam (2008). Finite

element modelling for piled raft foundation in sand, Proceedings of Eleventh East Asia-

Pacific Conference on Structural Engineering & Construction, Taiwan, 1-8.

12. Nguyen, D. C. C., D. S. Kim, and S. B. Jo (2013). Settlement of piled rafts with different

pile arrangement schemes via centrifuge tests, Journal of Geotechnical and

Geoenvironmental Engineering, 139, 10, 1690-1698.

13. Poulos, H. G. (1981). Methods of Analysis of Piled Raft Foundations. A report prepared

on behalf of Technical Committee TC18 in Piled Foundations, International Society of Soil

Mechanics and Geotechnical Engineering, July 1981.

14. Poulos, H. G. and E. H. Davis (1980). Pile Foundation Analysis and Design. Wiley, New

York.

15. Poulos, H. G. (1989). Pile behaviour-theory and applications, Geotechnique, 39, 3, 365

415.

16. Poulos, H. G. (1991). Analysis of piled strip foundations, Proceedings of Conference on

Computer Methods and Advances in Geomechanics, Rotterdam, 183-191.

17. Poulos, H. G. (1993). Piled rafts in swelling or consolidating soils, Journal of Geotechnical

Engineering, 119, 2, 374-380.

18. Poulos, H. G. (1994). An approximate numerical analysis of pile-raft interaction,

International Journal for Numerical and Analytical Methods in Geomechanics, 18, 73-92.

19. Poulos, H. G. (2001). Piled raft foundations: Design and applications, Geotechnique, 51, 2,

95-113.

20. Poulos, H. G. (2002). Design methods for pile groups and piled rafts, Proceedings of Deep

Foundations: An International Perspective on Theory, Design, Construction, and

Performance, Florida, 441-464.

21. Poulos, H. G. (2012). Foundation design for tall building, Proceedings of Geo Congress

2012: State of the Art and Practice in Geotechnical Engineering, California, 786-809.

22. Poulos, H. G. (2017). Tall Building Foundation Design. CRC Press, Florida, USA.

23. Randolph, M. F. (1994). Design methods for pile groups and piled rafts, Proceedings of

13th International Conference on Soil Mechanics and Foundation Engineering, New Delhi,

5, 61-82.

24. Small, J. C. and H. H. Zhang (2002). Behavior of piled raft foundations under lateral and

vertical loading, International Journal of Geomechanics, 13, 1-16.

25. Ta, L. D. and J. C. Small (1996). Analysis of piled raft systems in layered soils,

International Journal for Numerical and Analytical Methods in Geomechanics, 20, 57-72.

26. Wulandari, P. S. and D. Tjandra (2015). Analysis of piled raft foundation on soft soil using

PLAXIS 2D, Proceedings of 5th International Conference of Euro Asia Civil Engineering

Forum, Surabaya, Indonesia, 363-367.

38

NATIONAL WORKSHOP ON

RECENT ADVANCES IN GEOTECHNICS FOR INFRASTRUCTURE RAGI – 2020

MYSORE

PROGRAM SCHEDULE

Webinar, 14-17 May, 2020

Session Time Speaker Title

1 14/05/2020

Thursday

11.00 am to 11.30 am Online Inauguration

11.30 am to 12.15 pm Prof. M.R. Madhav Professor Emeritus

IIT H & JNTU

Hyderabad

Some Challenging Geotechnical Solutions

12.15 pm to 12.30 pm Q & A Session

2 15/05/2020

Friday

11.00 am to 12.00 Noon Er. P. Mohan Prasad

CEO, GEOMATRIX

Bengaluru

Some common misconceptions about Geotechnical Investigations

12.00 Noon to 12.30 pm Q & A Session

3 16/05/2020

Saturday

11.00 am to 12.00 Noon Er. I.V. Anirudhan

CEO, Geotechnical

Solutions, Chennai

Significance of Case Studies in Geotechnical Engineering

12.00 Noon to 12.30 pm Q & A Session

4 17/05/2020

Sunday

11.00 am to 12.00 Noon Dr. G.R.

Dodagoudar

Professor

IIT Madras, Chennai

Materials, the environment and Piled raft foundation

12.00 Noon to 12.30 pm Q & A Session

39

RAGI - 2020

India has prioritized infrastructural development and urban

places in the country are growing rapidly in recent times. The

most challenging projects include train services in hilly

terrain, metro trains, road flyovers and grade separators in

cities, development of road network, improvement in energy

sector, housing, connecting rivers, etc. The construction

industry has advanced to new heights in recent times with the

advent of modern technology. The construction of roads,

bridges, tunnels, retaining walls, embankments, foundations

of structures, stabilization of slopes, improving ground etc.

are the basic elements of infrastructural growth. These

structures are analysed, designed and constructed based on

the expertise available in Geotechnical engineering. Hence,

RAGI-2020 is evolved and the following topics shall be

addressed.

Some Challenging Geotechnical Solutions

Significance of Case Studies in Geotechnical Engineering

Some common misconceptions about Geotechnical

Investigations

Materials, the environment and Pile raft foundation

Eminent and senior geotechnical engineers and practitioners

of the country are sharing their expertise covering specific

case studies. Civil engineers involved in infrastructural

development will find this workshop interesting and useful.

Academicians, Builders, Consultants, Developers, Engineers

and students can be benefited from the workshop. In the

present pandemic situation, the workshop is expected to

create greater interest among the professionals.

ACCE (I), Mysore Centre

Association of Consulting Civil Engineers (India) was

formed and registered in 1985 by a group of Consulting

Civil Engineers in Bangalore. The main focus of the

association is to encourage and foster the ideals of

profession, to hold conferences/meetings/seminars for

dissemination of knowledge amongst the civil engineers in

particular and the society at large. ACCE (I) has it’s

headquarter at Bangalore, and 22 centres formed all over

India. It publishes quarterly bulletin and seminar

proceedings. Association has formulated

Professional development committee and Technological

development committee. Mysore Centre of ACCE (I) was

started in 2000 with 20 members and now it has grown to

150 and is growing steadily. The Mysore centre has

organized many workshops, seminars, expert lectures and

technical visits, and RAGI 2020 is one such activity.

IGS Bengaluru Chapter

Established in 1948, Indian Geotechnical Society (IGS) is

one of the top most Civil Engineering societies in India. IGS

aims at promoting co-operation amongst engineers and

scientists for the advancement and dissemination of

knowledge in the fields of Soil Mechanics, Foundation

Engineering, Soil Dynamics, Engineering Geology, Rock

Mechanics, Snow and Ice Mechanics and allied fields and

their practical applications. It provides a common forum for

academicians, research workers, designers, construction

engineers, equipment manufacturers and others interested in

geotechnical activity. It has 40 local chapters out of which

Bengaluru is one of the vibrant and most active chapters. It

has hosted many prestigious conferences such as IGCs, ARC,

etc.

NIE

The National Institute of Engineering (NIE) in Mysuru is one

of the leading institutions in the country imparting high

quality value based education. NIE was started in 1946 with

Civil Engineering stream and it has grown over the years.

The institution now offers various under graduate, post

graduate and doctoral programs in different disciplines. NIE

is approved by All India Council for Technical Education and

Accredited by National Board of Accreditation as well as

National Assessment and Accreditation Council. NIE was

accorded autonomous status under Visvesvaraya

Technological University, Belgaum during the year 2007.

The first two phases of prestigious World Bank project

TEQIP have been successfully completed and TEQIP

Phase III is now in progress. NIE has highly qualified and

competent faculty and state of the art infrastructure. Over

the years NIE has established centres of excellence in

various fields of engineering. Impressive placement

record, regular short term courses for students and

working professionals, consultancy services, interaction

with industry, training programs to aspiring students by

means of additional certificate / diploma programs

through experts in the field and Alumni interactions are

some of the unique features of NIE.

SJCE

Sri Jayachamarajendra College of Engineering (SJCE) in

Mysuru was established in the year 1963 under the aegis

of JSS Mahavidyapeetha. It has carved a niche for itself as

a premier centre for Technical Education. Well-equipped

and sophisticated laboratories, Library and sports facility,

highly qualified and experienced faculty and staff

members, well-designed college campus are the reasons

for its success. The college is now a part of J.S.S. Science

& Technology University. It is approved by All India

Council for Technical Education and accredited by

National Board of Accreditation and is governed by the

Grant-in-Aid rules of Govt. of Karnataka. It successfully

completed World Bank assisted TEQIP I and TEQIP II

Schemes of Govt. of India and is a part of TEQIP III. Its

motto is ‘Commitment to Technical Education’. It offers

under graduate, post graduate and doctoral degrees in

almost all established engineering disciplines. Excellent

placement records, impressive interaction with industry

and user system, active consultancy, always energetic

alumni network, keen interest in offering CEP courses and

conducting workshops and conferences enhance the brand

name of SJCE.

40

Registration

Registration is free for all participants of webinar. It is

expected that maximum number of delegates make the best use of this unique online workshop.

Speakers

Prof. M.R. Madhav

Professor Emeritus

IIT H & JNTU Hyd.

Er. I.V. Anirudhan

CEO, Geotechnical

Solutions, Chennai

Er. P. Mohan Prasad

CEO, GEOMATRIX

Bengaluru

Dr. G.R. Dodagoudar

Professor, IIT Madras

Chennai

Webinar Schedule

14/05/2020

Thursday

11.00 am

to

11.30 am

Inauguration

Lecture 1

14/05/2020

Thursday

11.30 am

to

12.30 pm

Prof. M.R. Madhav

Some Challenging

Geotechnical Solutions

Lecture 2

15/05/2020

Friday

11.00 am

to

12.30 pm

Er. P. Mohan Prasad

Some common misconceptions

about Geotechnical

Investigations

Lecture 3

16/05/2020

Saturday

11.00 am

to

12.30 pm

Er. I.V. Anirudhan

Significance of Case Studies in

Geotechnical Engineering

Lecture 4

17/05/2020

Sunday

11.00 am

to

12.30 pm

Dr. G.R. Dodagoudar

Materials, the environment and

Pile raft foundation

Patrons Prof. T. N. Nagabhushana, Principal, SJCE, Mysuru Prof. Rohini Nagapadma, Principal, NIE, Mysuru Prof. K. Prakash, Head, Civil Engg., SJCE, Mysuru Prof. K.C. Manjunath, Head, Civil Engg., NIE, Mysuru Er. S. Prakash, Chairman, ACCE (I) Mysore Er. M.S. Ramprasad, Hon. Secretary, ACCE (I) Mysore Dr. C.R. Parthasarathy, Chairman, IGS B’lore Chapter Prof. P. Anbazhagan, Secretary, IGS B’lore Chapter Er. Anil Kumar Pillai, Ramco Cements

Organizing Committee Prof. G.S. Suresh, Consultant, Mysuru Prof. Y.M. Manjunath, NIE, Mysuru Prof. Madan Kumar L, NIE, Mysuru. Prof. Hema. H., NIE, Mysuru Prof. Vedaprada, NIE, Mysuru Er. H.N. Vijaya Vittal, Consultant, Mysuru Er. B.R. Badrinath, Consultant, Mysuru Prof. S.B. Basavaraj, JSSPW, Mysuru Er. S. Shashiraj, Consultant, Mysuru Er. H.S. Deepak, Consultant, Mysuru Er. C.S. Srikanth, Consultant, Mysuru Prof. C.N. Yadunandan, Consultant, Mysuru Prof. S. Raviraj, SJCE, Mysuru Prof. G.P. Chandradhara, SJCE, Mysuru Prof. P. Nanjundaswamy, SJCE, Mysuru Prof. H.P. Thanu, SJCE, Mysuru Prof. H.N. Ramesh, Principal, UVCE, B’luru Prof. G. Madhavilatha, I.I.Sc., Bengaluru Er. Shashank Sharma, Ramco Cements Er. Santhosh R., Ramco Cements

For further information, please contact Dr. H.S. Prasanna, Chairman, RAGI 2020 Professor of Civil Engineering NIE, Mysuru 570 008 E Mail: prasanna@nie.ac.in Mobile: +91-94490-89784

Dr. S.K. Prasad, Secretary, RAGI 2020 Former Professor of Civil Engineering SJCE, Mysuru 570 006 E Mail: prasad_s_k@hotmail.com Mobile: +91-94496-21994

Web link: https://godrejandboyce.webex.com/godrejandboyce/on

stage/g.php?PRID=24940b9ff0c4ce356a207d02e7f332d6

Password : 12345

MYSORE

National Workshop on Recent Advances in Geotechnics

for Infrastructure (RAGI 2020)

Jointly organized by

Association of Consulting Civil Engineers (India), Mysore Center

Indian Geotechnical Society Bengaluru Chapter

The National Institute of Engineering Mysuru

and

Sri Jayachamarajendra College of Engineering, Mysuru

14-17 May, 2020

41

NATIONAL WORKSHOP ON

RECENT ADVANCES IN GEOTECHNICS FOR INFRASTRUCTURE RAGI – 2020

MYSORE

DETAILS OF SPEAKERS

14-17 May, 2020

Sl

No Speaker Photo

1

Prof. M.R. MADHAV

Professor Emeritus

IIT H & JNTU

Hyderabad

Ph: +919866228583

Email: madhavmr@gmail.com

2

Er. P. MOHAN PRASAD

CEO, GEOMATRIX

Soil & Foundation Consultant

Bengaluru

Ph: +9198441-37668

Email: geomatrix@yahoo.com

3

Er. I. V. ANIRUDHAN

CEO, Geotechnical Solutions

Chennai

Ph: +919841106580

Email: anirudhen@gmail.com

4

Dr. G. R. DODAGOUDAR

Professor of Civil Engineering,

IIT Madras, Chennai 600036

Ph: +919840328754

Email: goudar@iitm.ac.in

RAGI 2018 - 3rdMarch 2018 at SJCE, Mysuru

MYSORE