DMRC PROJECT REPORT(CC-27)

PROJECT REPORT (JUNE 2014 - DECEMBER 2014)

STUDY AND ANALYSIS OF THE

CONSTRUCTION OF DELHI METRO RAIL CORPORATION (CC- 27)

Submitted by

Sukhdarshan Singh - 101102073

Under the Guidance of

Mr. Tanuj Chopra

Assistant Professor

Thapar University

DEPARTMENT OF CIVIL ENGINEERING

THAPAR UNIVERSITY, PATIALA

(Declared as Deemed-to-be-University u/s 3 of the UGC Act, 1956)

1

DELHI METRO RAIL CORPORATION

The Delhi Metro is a mass-rapid transit system serving Delhi, Gurgaon, Noida and Ghaziabad in the

National Capital Region of India. Delhi Metro is a metro system serving Delhi, Gurgaon, Noida, and

Ghaziabad in the National Capital Region of India. Delhi Metro is the world's thirteenth largest

metro system in terms of length. Delhi Metro is India's second urban mass rapid transportation

system, after Kolkata Metro. As of June 2014, the network consists of five colour-coded lines (Red,

Blue, Green, Yellow, Violet), plus a sixth .Airport Express line, with a total length of 193.2

kilometres serving 139 stations, (including the 6 Airport Express stations), of which 38 are

underground, five are at-grade, and the rest are elevated.

It is also India’s first modern public transportation system, which has revolutionized travel by

providing a fast, reliable, safe and comfortable means of transport. The present network consists of

six lines with a total length of 189.63km with 142 stations. Delhi Metro was planned to be built in

phases spread over around 20 years as with each phase having a target of five years and end of one

phase marking the beginning of another. Phase I (65 km) and Phase II (125 km) were completed in

2006 and 2011, respectively, and Phase III and Phase IV are scheduled for completion in 2016 and

2021, respectively. Work on Phase III started in 2011 while planning for Phase IV has begun. Ex-

chief of DMRC hinted that by the time Phase IV is completed, the city will need Phase V to cope

with rising population and transport needs.

2

LARSEN & TOUBRO

Larsen & Toubro Limited (L&T) is amongst one of India’s largest technology, engineering

construction and manufacturing conglomerate. L&T is considered to be the "bellwether of India's

engineering sector”, and was recognized as the company of the year in 2010. Its business structure

has a dominant presence in India's infrastructure, power, hydrocarbon, machinery, shipbuilding and

railway sectors. L&T has an international presence. The company's businesses are supported by a

wide marketing and distribution network, and have established a reputation for strong customer

support. With more than a seven decades of dedicated customer focused service and continuous

quest for world class quality have established them as the leader of the Engineering and Construction

sector in India.

3

SHANGHAI URBAN CONSTRUCTION GROUP

SUCG Infrastructure India Pvt. Ltd. is an international company which integrates overseas

construction, design and management, investment, and sales of construction equipment. Shanghai

Urban Construction (Group) Corporation, established in October 1996 with the approval of Shanghai

Municipal Party Committee and the Government, is a comprehensive enterprise particularly

supported by the Ministry of Construction and Shanghai Municipal Government. It is authorized by

Shanghai State-owned Asset Management Committee to manage the state-owned assets within the

Group. Shanghai Urban Construction (Group) Corporation has the special class qualification for

municipal public works, the first-class general contracting qualifications for highway construction,

housing, etc.

4

L&T SUCG JV CC-27, New Delhi PROJECT FEATURES

INTRODUCTION

L&T in a joint venture with SUCG won an order worth 12.526 billion from DMRC.

CONTRACT FEATURES

Under the terms of the contract, the Heavy Infrastructure IC of L&T Construction and SUCG will

design and construct a tunnel between Shankar Vihar and Hauz Khas, as well as underground

stations at Vasant Vihar, Munirka, R.K. Puram, I.I.T. and Hauz Khas.

CONTRACT

Design and construction of tunnel from end of underground ramp (Near Shankar Vihar Metro

Station) to Hauz Khas Metro Station and an underground ramp near Shankar Vihar Metro Station

and underground Metro Stations at Vasant Vihar, Munirka, R.K. Puram, I.I.T. and Hauz Khas on

Janakpuri West-Botanical Garden corridor of Delhi Metro Project of Phase-III .

PROJECT FEATURES

-SUCG JOINT VENTURE

KS DESIGNER: Tandon Consultants Pvt. Ltd.

-PASSAGE DESIGNER: SUCDRI

ECT: 6.82KM

GEOTECHNICAL REPORT CASE STUDY

Before starting construction Geotechnical data was collected from various locations along the

proposed route to know about tje soil characteristics. Bore Holes were made along the

proposed route up to a depth of 30M below existing ground level or REFUSAL whichever is

first.

Refusal here is defined as when SPT field value reaches 100 or more for a penetration of

30cm or less. And where ever refusal is encountered before reaching the required depth. The

bore hole is extended further by using HYDRAULIC FEED ROTARY DRILLING.

SPT (Standard Penetration Test was carried out every 1.5m interval and disturbed soil

samples were collected. Undisturbed soil samples were collected at every 3m or change of

strata which ever was earlier. So in total 45 bore holes were dug out. Split spoon sampler was

used for collecting the samples.

Boring was done using Shell and auger method and IS 1892-1979 was followed.

Following tests were then performed on the collected samples-

Sieve analysis.

Hydrometer testing

Moisture content

Specific gravity

Dry Density

Atterbergs limit

Triaxial shear test(uu, cu, cd)

Consolidation test

Direct Shear Test

Chemical analysis of both soil and water samples

The collected rock core samples were taken and the following tests were conducted on them-

Density test

Water absorption& porosity

Hardness

Ucs

Point load index

Modulus of elasticity


Abrasion testing

Bore holes through all type of soils were bored using shell and auger method. Further

bore holes through rocky strata were drilled using hydraulic feed rotary drilling

machine with double tube core barrel . To retain the bore holes the casing pipe was

used up to the entire depth of bore holes .The details of various bore holes conducted

at site and the location is shown in the above figure.

ROCKY

STRATA SOIL/SOFT

STRATA


STUDY OF BORE HOLE DATA

Standard penetration tests were conducted in the above bore holes at regular interval

in depth & at change of strata as per specifications / instructions of Engineer-in-

Charge. The bores were cleaned up to the desired depths. Standard split spoon

sampler attached to lower end of 'A' drill rods was driven in the bore holes by means

of standard hammer of 65 0 kg falling freely from a height of 75 cm. The sampler was

driven 45 cm as per specifications & the number of blows required for each 15 cm

penetration were recorded. The number of blows for the first 15 cm were not taken

into account. This was considered as seating drive. Wherever total penetration was

less than 45 cm, the number of blows & the depth penetrated is incorporated in the

respective bore logs. The number of blows for next 30 cm penetration were

designated as SPT 'N' value. Disturbed soil samples obtained from standard split

spoon sampler for all the above standard penetration tests were collected in polythene

bags of suitable size. These samples were properly sealed labeled, recorded and

carefully transported to the laboratory for testing.

Undisturbed soil samples were collected from the bore holes at regular interval in

depth & at change of strata as per sampling specifications, in thin walled sampling

tubes of 100 mm dia and 450 mm length fitted to an adopter with ball and socket

arrangement were collected. These sampling tubes after retrieval from the bore holes

were properly sealed at both ends. These were carefully labeled and transported to the

laboratory for testing.

The depth of ground water table was checked/measured in all the bore holes, after

completion of bore holes & on full stabilization of ground water table. The ground

water table was encountered only at the locations of bore holes BH-34 A, BH-35 &

BH-36 at depths, 37.66 m, 32.10 m & 32.60 m respectively below the existing

ground level.

Ground water samples were collected from bore holes BH-35 & BH-36 and stored in

suitable plastic containers of 5 litre capacity having air tight lids. The samples were

properly labeled, scaled and careful!) Transported to the laboratory for chemical

analysis.


TEST RESULT COMARISON FOR BH-61,62 & BH -35,36

BH-61(VASANT VIHAR METRO STATION) LOCATION-AS SHOWN IN FIGURE BORING METHOD-ROTARY DRILLING

From existing ground surface to 2.00m depth consists of filled up soil.

From depth 2.00m to 22.50m depth consists of whitish brown medium to coarse

grained highly fractured partially decomposed micaceous quartzite.

Ground Water Table was not encountered.

Whitish Brown Medium to coarse grained Highly Fractured Partially Decomposed

Micaceos Quartzite(Physical Characteristic Of encountered rock)

RQD Stands for rock quality Designation- RQD is a modified core recovery

percentage in which all the pieces of sound core over 10 cm long are counted as

recovery, and are expressed as a percentage of the length drilled. The smaller pieces

resulting from closer jointing, faulting or weathering are discounted. The rock quality

designation (RQD), is a simple and practical method of describing the quality of core

from borings.

BORE HOLE NO COORDINATE E : N

REDUCED LEVEL(m)

DEPTH OF BORE HOLE(m)

DEPTH OF GROUND WATER TABLE (m)

BH-61 8641.464 -1193.61 -241.95 22.50 NIL


Sound rock usually furnishes high recoveries, often about 100 percent, seamy and or

jointed rock may furnish low recovery and badly broken cores.

From the study of the results of field work & laboratory tests carried out on selected

rock core samples collected from the locations of nine bore holes (BH-41, BH-44.

BH-50, BH-51, BH-54 to BH-58, BH-61 & B11-64 to BH-66) . It is revealed that the

core recovery & R.Q.D. values are very low at most of the places ranging from 6% to

47A. At the locations of bore hole BH-41. BH-44. BH-54 & BH-58 core recovery is

nil. Further at the locations of bore holes BH-41m BH-44, BH-54,BH-56,BH-58 &

BH-65. RQD. value is nil indicating moderate!) to highly weathered decomposed rock

formation. The unconfined compressive strength of the rock core samples (wherever

available) mostly ranged from 130 kg 'cm to 1039 kg/cm2.

Test Result

Density test 2.01 to 2.47(g/cc) Varying with depth

Abrasion test 28.0%

UCS


Hardness 7 to 7.5(Mohr Scale)

Porosity .83 to 7.14 Varying with depth

UCS 217kg/cm2

Pont Load Test Index 395.0 to 545.0 kg/cm2

Modulus of elasticity .36 to .52kg/cm2


BH-35(Hauz Khaz Metro Station) LOCATION AS SHOWN IN FIGURE BORING METHOD-SHELL AND AUGER BORING

BH-35

From existing ground surface to 8.00 m depth consists predominantly of fine gained

soils i.e. sandy silt of low plasticity (CL/ML-CL) having SPT field ‘N’ values mostly

ranging from 11 to 29 showing stiff to very stiff consistency of the strata. From depth

8.00 m to 35.45 m depth consists predominantly of fine gained soils i.e. sandy silt of

low plasticity (CLJML-CL) having SPT field 'N’ values mostly ranging from 30 to

more than 100 showing hard consistency of the strata.

BH-36

At the location of bore hole BH-36. From existing ground surface to 1.00 m depth

consists of filled-up soil. From depth 1.00 m to 6.00 m depth consists predominantly

of fine grained soil i.e. 3,33, of low plasticity (ML-CL) having SPT field 'N' values

mostly ranging From 16 to 25 showing very stiff consistency of the strata. from depth

BORE HOLE NO COORDINATE E : N

REDUCED LEVEL(m)

DEPTH OF BORE HOLE(m)

DEPTH OF GROUND WATER TABLE (m)

BH-35 12977.800 -2802.410 224.200 35.45 32.10

BH-36 12865.590 -2777.610 224.500 35.45 32.60


6.00 m to 35.45 m depth consists predominantly of fine grained soils i.e. sandy silt of

low plasticity (CL/ML-CL) having SPT field `N' values mostly ranging from 32 to

more than 100 showing hard consistency of the strata.

The depth of ground water table was checked/measured in all the bore holes. After

completion of bore holes & on full stabilization of ground water table. The ground

water table was encountered only at the locations of bore holes BH-34A. BH-35 &

BH-36 at depths 10.90 m. 37.66 m. 32.10 m & 32.60 m respectively below the

existing ground level .

From the results of chemical analysis of two water samples from bore holes BH-35 &

BH-36.it is revealed that PH value ranged from 7.1 to 7.2. Chloride content (as CL)

from 40 ppm to 55 ppm & Sulphate content (as SO3) from 29 ppm to 37 ppm. From

the study of above results it is revealed that the various contents are within

permissible limits as per IS:456-2000 & no precautions are required due to this.

Above test results & interpretations are drawn based upon the field data collected

from the locations of various bore holes and results.

SHELL&AUGER DRILLING




DEPTH(m) GRAVEL (%)

SAND (%)

SILT (%)

CLAY (%)

LL

PL PLASTICITY INDEX(IP )

COHESION (KG/CM2)

Refer To Graph

1.5 4 39 52 5 24 18 6 .35 3 2 33 55 10 27 20 7 .45 6 1 11 73 15 33 21 12 .65 9 2 13 76 9 30 20 10 .75 12 3 13 72 12 32 21 11 1.20 15 0 46 46 8 24 18 6 1.30 18 4 34 56 6 24 18 6 1.4 21 12 26 47 15 29 20 9 1.64 24 2 34 54 10 28 19 7 - 27 6 21 65 8 29 20 9 - 30 8 18 63 11 30 20 10 -

33 7 30 48 15 29 20 9 -



GRADATION CURVES OF THE SOIL SAMPLES OBTAINED FROM A SPT AND SUBJECTED TO

SIEVE ANALYSIS.

TEST RESULTS FOR TRIAXIAL HEAR TEST(UUT)

BORE HOLE-35

DEPTH-1.50M

COHESION-.35kg/cm2

ANGLE OF FRICTION-14DEG

DENSE SAND AND OVER

CONSOLIDATED CLAY

BORE HOLE-35

DEPTH-18M

COHESION-1.35kg/cm2

ANGLE OF FRICTION-14DEG

DENSE SAND AND OVER

CONSOLIDATED CLAY

1

2


CONSOLIDATION STUDIES FOR SOIL

DEPTH-1.5M

There are various methods for determining the pre consolidation pressure from

lab data. The data is usually arranged on a semi log plot of the effective stress

(frequently represented as σ'vc) versus the void ratio. This graph is commonly

called the e log p curve or the consolidation curve.

CONSOLIDATION

PRIMARY -Time Dependent

-Due To Expulsion of Pore Water

SECONDARY

-Time Dependent

-Very Slow

-Due To Plastic Readjustment of soil

CONVEX IN

SHAPE HENCE

THE SOIL IS

OCC OCS-OVER CONSOLIDATED SOIL

NCC-NORMALY CONSOLIDATED

Cr= (.2 to .1)CC

Cc= -(e2 – e1 )/log(0--- 1 – 0---

2 )

Cc=.156

1-2 VIRGIN COMP CURVE

2-3 SWELLING CURVE

SOIL TYPE-ML-CL

DEPTH-1.5M

NCC

STRAIGHT

LINE

1

2

3


TIME FAVTOR(Tv)

Time factor is a parameter which relates to DOC (Degree of compaction and time

required for that consolidation. It depends upon following

Degree of Consolidation

Length of Drainage Path

Time of Consolidation

Coeff of Consolidation(Cv)

We will determine Cv using Taylors Method (Square Root For Time fitting

Method).By making use of time required for 90% Consolidation.

3.4

90% Of

Consolidation

point

Di

D0

T90=3.42=11.56Min

Drainage Path Length=1cm

Cv=(.848*1)/(11.56*60) = .00124cm2/sec

Refer To side graph for steps of construction


SIMILAR PROCEDURE WERE ADOPTED TO FIND Cv And Cc With

Changing Depth.

Increment of .5kg/Cm2 of pressure for finding Cv through T90


Geotechnical report suggested using

1. Bottom-up Construction technique for construction at VASANT VIHAR SITE

2. Top To Bottom Construction for HAUZ KHAS SITE.

1.5, 0.353, 0.45

6, 0.659, 0.75

12, 1.215, 1.3

18, 1.4

21, 1.64

00.10.20.30.40.50.60.70.80.9

11.11.21.31.41.51.61.71.8

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

CO

HES

ION

DEPTH

COHESION VS DEPTH BORE HOLE-35

BOTTOM-UP CONSTRUCTION AND TOP TO BOTTOM CONSTRUCTION

As suggested by the testing and Geotechnical report Suitable methods are selected for

construction at sites according to the location and soil properties. Here we are going to

discuss about 2 such methods

Bottom Up construction

Top to Bottom construction

The choice of selection of method depends on a so many factors like-

Soil Profile- As suggested by the geotechnical investigation.

Site Location-The site is located in an isolated environment or urban dwellings.

Cost Incurred -Depends

Surrounding Environment-Weather the Surrounding environment consists of existing

structures and road networks.

Time Constrain-The total time available for completion of project.

Availability of Material-The availability of material for filling and construction

Activities to be carried out.

Both the methods have their own merits and demerits and we will study about the

methods one at a time.

BOTTOM-UP CONSTRUCTION

Vasant Vihar is the only metro station of the project CC-27 which is

constructed using Bottom-Up construction methodology. The ground

profile of this station is medium hard rocks. As a result of this, bottom

method is preferred for this particular station.

TOP VIEW-VASANT VIHAR


In bottom-up construction, a trench is excavated more than the required

size of the station. Then the trench is backfilled and the surface is restored afterwards

Important components in bottom up approach are

Earthworks

Excavation and Temporary Retaining structures- Rock

anchoring/ Strut waler arrangement.

RCC Works- Columns, Beams, Slabs, External Wall.

Plunge in Column

1. EXCAVATION

Excavation should be carried out by

mechanized method up to the formation

level at stages. The activities for carrying

out excavation are mainly rock excavation,

shot Crete, rock bolting, disposal of

excavated materials and grout monitoring.

Excavation should be carried out in proper

sequence. Before excavating, a trial trench

is dug for a depth of 1.5m.

Also, the site should be checked for utility lines and proper diversions should be done

beforehand. Traffic divers on plans should be made and it should be diverted before

starting the excavation.

According to IS 3764:1992

All trenches in soil more than 1.5 m deep shallbe securely shored and timbered.

All trenches in friable or unstable rock exceeding2 m in depth shall be securely

shored and timbered.

Excavation of the soil can be done in two ways depending on the soil profile.

EXCAVATION BEING CARRIED OUT


Braced excavation method-

Installing horizontal struts (use lateral

pressure against lateral soil pressure) in

front of retaining walls to resist the earth

pressure on the backs of walls is called

the braced excavation method. The

bracing system consists of horizontal and

diagonal struts, Waler beams, king posts

and runner beams. In Project CC- 27,

the structural steel used for fabrication of all these components of the bracing system

using UB 610. The function of Waler beams is to transfer the earth pressure on the back of

the walls to the strut assembly. Installation of the bracing struts is done by excavating soil

locally around the strut and only continuing the excavation once preloading is complete.

Cross-lot bracing makes sense in narrow excavations (60ft to 120ft) when tieback installation

is not feasible. The struts can bend excessively under their own weight if the excavation

spacing is too large. In addition, special provisions have to taken to account for thermal

expansion and contraction of the struts.

SOLDIER PILES-Soldier piles or soldier beams are H-piling set in predrilled holes around

the periphery of an excavation. Predrilling as opposed to driving is used to provide close

control of alignment and location. These piles are then grouted in place with weak concrete.

Lagging is the timber placed horizontally between the soldier piles to retain the soil behind

the excavated area. Pairs of soldier beams are driven to a depth slightly below the final

excavation. Their spacing is in the order of 2-4 meter so that available timber can be used for

lagging. The lagging timber, which is slightly shorter than the spacing but on the order of 2 to

4 inches thick, are installed behind the front flange to retain the soil as excavation proceeds.

Some hand excavation is usually required to get the lagging into the place.

INITIAL STAGES OF SOLDIER PILE INSTALLATION AT SITE


Soldier piles are installed with conventional pile-driving equipment or in augured holes. The

horizontal sheeting or lagging is installed behind the flange closest to the excavation (inside

flange). The sheeting can be installed on the inside face of the front flange and held in place

by various methods such as clips, welded studs, or bars, etc. Figure 5 shows two photos of

excavation supports using soldier beam and lagging. The soldier pile and lagging method is

inappropriate for perfectly cohesionless soil. For cohesionless soils sheeting must be used.

PROCEDURE

A. Strike soldier piles into soil. In non-urban areas, it will be all right to strike them into

soil directly. In urban areas, however, static vibrating installation would be the better

way to have soldier piles penetrated into the soil. If encountering a hard soil layer,

pre-bore the soil (AS DONE ON SITE).

B. Place laggings as excavation proceeds. Then backfill the voids between soldier piles

and laggings.

C. Install horizontal struts in proper places during the excavation process once excavation

is completed, begin constructing the inner walls of the basement. Then remove struts

level by level and construct floor slabs.

ADVANTAGES DISADVANTAGES

I Easier and faster construction with lower cost.

2 Piles can be easily pulled out.

3 It is necessary that less ground disturbance is caused

when pulling out the piles, compared to pulling out sheet

piles.

4 The pile tip can be strengthened with special steel

materials for use in gravel soils.

5 Soldier piles are reusable.

I Sealing is difficult. In sandy soils with high

groundwater level some dewatering measures may be

necessary.

2 Installing soldier piles by striking will cause much

noise and vibration. The latter will render sandy soils

below the foundation denser in such a way that uneven

settlement of the adjacent buildings may occur.

3 Backfilling is necessary if soldier piles are driven

using pre-boring.

5 Removing piles will disturb the surrounding soil.

2-4 Meters


Anchored Excavation Methods-

Anchored excavation methods substitute anchors force to counteract the lateral earth

pressure. The configuration of an anchor can be divided into

(a) The fixed section- which offers anchoring force

(b) The free section- which transfers the anchoring force to the anchor head.

(c) The anchor head- which locks the tendons and transfers the anchoring force to the

structure.

The anchored excavation counts solely on soil

strength to offer the anchoring strength. The higher the soil strength, the stronger the

anchoring force and vice-versa. Granular soils as sandy soils or gravel soils have high

strengths and thus offer strong anchoring force while clay has weak strength and creep will

further decrease the anchoring force. Therefore, the anchoring section should avoid being

installed in clay.

The anchorage process involves the following steps

o Drilling Processes

o Anchor installation and grouting

o Waler beam installation

o Pre Stressing

o De-Stressing

o Quality Assurance and quality control(Qa-Qc Procedures)


DRILLING PROCESS-

-Drilling is carried out typically inclined at an angle of

(20+ -5deg) to the horizontal as required Using a

suitable anchor drilling rig with appropriate drill tools

to frill a hole of( 152mm Dia and length from 7m to

13m)

-It shall be ensured to have full length casing during

drilling process with due considerations to collapse in-

site soils, in order to stabilize the boreholes. However

casing is not required when drilling through rock mass

as it is not a collapsible stratum.

-During the drilling operation the sequence of strata in

the ground needs to be observed continuously. It must

be ensured that the fixed/bond length of the anchor

does not

Fall under a soil stratum that is significantly different from that of the idealized soil strata.

-Once the required depth of the borehole has been reached the hole is flushed out using air

and the drill tools are removed from the hole.

Anchor Installation and Grouting

-High tensile strength strands shall be used conforming to IS14268:1995 to achieve the

desired structural capacities and the prefabricated anchor shall be tied together with HDPE

grout pipe for grouting process (secondary Grouting)

-A shrink free grout mixture is used (typically water cement ratio shall be .35 to .4) with

approved OPC grade 53 shall be used with the admixture CEBEX 100.

-The prefabricated anchor assembly is then inserted into the borehole and grout is injected

either through HDPE grout pipe or gravity flow from top of the bore hole using grout station

(Consisting of a colloidal mixer, agitator and high pressure grout pump)

-During this process the casing shall be withdrawn in stages and the gap formed due to

retrieval of casing shall be filled-up with the grout. This procedure is repeated until the entire

casing is retrieved,


-Following primary Grouting process a secondary grouting process shall be commenced after

a time lapse of about 24 Hours. During secondary grouting through the Pre-Installed HDPE

grout pipe, High grout pressure for effective bonding between the primary and secondary

grout.

GROUT MATERIAL& PROPERTIES

-The purpose of grouting is to provide is to provide permanent bond in the fixed length of the

tendon. This also helps in stabilizing drilled holes in the free length. Grout also fills up void

spaces, expelling the water collection if any

GROUT PROPRTIES

o The cement grout is prepared based on W/C of .35 to .4

o The admixture Cebex-100 shall be added as of 225grams per 50kg cement bag.

o 100mm cube samples shall be taken from the grout mix for strength checks

o The grout temperature is maintained at 25deg Celsius.

GROUT STATION

GROUT MIXTURE


o The cube shall attain a minimum strength of 17N/mm2 in 7 days

INSTALLATION OF BRACKETS AND WALERS

-The brackets for each location shall be measure &Fabricated at site for fixing to the soldier

piles. Walters will be installed as H-Piles &Welded completely as specified in the drawing.

The gap between the waler beam and the soldier pile wall will be filled with concrete.

Bearing Plate shall be installed prior to stressing.

PRE-STRESSING

-The grouted anchors are allowed to cure for a minimum period of 7-10 days before the

anchor strands are subjected to pre-stressing. The Stressing, operations must not commence

until the grout has attained the required crushing strength of at least 17 MPa or 7days after

grouting whichever is earlier.

-As per BS 8081: 1989 (clause 11.4.3, table 18). While pre-stressing. each stage loading in

the first cycle should be held only for the time necessary to record the displacement (as

shown in table below).

- Each stage loading in the second Cycle should be held for at least 1 min and the

displacement recorded at the beginning and end of each period. For proof loads, this period is

extended to at least 15min. with an intermediate displacement reading at 5min.

- On completion of the second load cycle, reload in one operation to 110% and lock off.

Reread the load immediately after lock-Off to establish the initial residual load.

- The anchors will be locked at 110%of the Pre stressing load.

In general anchor capacity and performance are influenced by four main factors

(a) the number of strands to achieve the desired structural capacity

(b) Ground characteristics, especially shear strength, to achieve the desired geotechnical

capacity

(c) Installation techniques and

(d) Workmanship attained in the field.


DESIGN CRITERIA FOR ANCHOR BOLTS

(example)

Structural Capacity

To achieve the desired structural capacity of the anchors i.e., say 80 tons, the anchors are

Fabricated using 6 Nos. of each 12.7mm diameter steel strands (7 ply) confirming to

IS: 14268-1995, clause-II, were used as per the following calculations:

Design capacity of the anchor = 80 T

Capacity of each strand of 12.7mm dia. = 18.74 T

(As per IS 14268:1995 For 7 ply, 12.7 mm nominal dia., clause II)

No. of strands = 6nos (say)

Total Structural capacity of the anchor = 18.74T x 6nos = 112.44T

Factor of safety against STRUCTURAL capacity of the anchor

= Theoretical capacity / design capacity

= 112.4 T / 80T

= 1.41 > 1.4 (as per BS 8081: 1989)

Geotechnical Capacity

The main components of the geotechnical capacity of the anchor are free and fixed length,

Which are arrived at based on the following calculations:

Design Capacity of the anchor = 80T

Length of anchor in the active wedge zone = 10.5m (as per to failure wedge analysis)

Free length of anchor = 12.5m (incl. 2m additional buffer length)

Fixed length of the anchor, L = 9.5m (say)


Geotechnical capacity of the anchor = π x D x L x τf (Sandy silt)

D, Dia of drill hole = 0.152m

τf (Sandy silt) is theoretical skin friction (> 400 kN/sq.m) for Sandy Silts having Consistency

Index, Ic=1.25, according to BS 8081: 1989, clause 6.2.5.3, Fixed Length in Type C

Anchorages

Considering, theoretical skin friction τf (Sandy silt) = 400 kN/sq.m

The ultimate geotechnical capacity of anchor = (π x 0.152 x 9.5) x 400

= 1,815 kN ~ 182T

Factor of safety against geotechnical capacity of the anchor

= Theoretical capacity / design capacity

= 182 T / 80T

= 2.3 > 2 (as per BS 8081: 1989)

Total length of the anchor = Free length + Fixed length

= 12.5m + 9.5m = 22m

SHORTCRETE

Shortcrete is concrete conveyed through a hose and pneumatically projected at high velocity

onto the excavated surface, as a technique for stabilizing the excavated face. Shortcrete is

usually an all- inclusive term that can be used for both wet-mix and dry-mix versions.

Shortcrete undergoes placement and compaction at the same time due to the force with

which it is projected from the nozzle. Cement, sand, aggregates and water are the main

constituents of shotcrete. Prior to the application of shotcrete, all surfaces to receive

shotcrete shall be cleaned with compressed air.

o Admixtures: Admixtures for the improvement of performance, workability, etc.

o Water: Water free from solid suspended matter and organic particles confirming to

IS: 456-2000

o Flyash: Flash shall comply with Specification IS:3812.


o Accelerator: Accelerator will be Alkali free, and dose will be max. 6% by wt. of

Cement.

-After the preparation of surfaces 4mm wire mesh is

fixed to the concrete surface with pin/8m dia and to the

earth surface with 25-32mm dia reinforcement bar 1500-

3000mm c/c

-The operation temperature for Shortcrete is 5 – 32deg

Celsius

-MIX DESIGN PROPORTION USUALLY ARE 1:3

to 1:5 depending upon the surface.

-Shortcrete is transported by transit mixer from the

batching plant to site and will be delivered into hopper of

concrete spraying machine.

-The designed thickness of the Shortcrete will be built up

in layers of about 75mm thick. The nozzle for spraying will be kept at a distance of 1 to 1.4m

away from surface and always perpendicular to the surface.

-Before a subsequent layer of shortcrete is applied the percentage layer will be checked for

defects. Defects like voids, dry or sandy patches will be cut and then re-Shortcrete.

-The area of spray should not be less than 300mm*300mm

-Initially fix the wire mesh then spray the Shortcrete up to 75mm, after the drill hole for

installation of rock bolt. So Shortcrete around rock bolt is not required

-To check the thickness of the Shortcrete coring will be done.

ON FIELD

1) Clean the surface off the loose material and then clean with air compressor.

2) Apply a layer of shortcrete to the surface and wait for it to cure.

3) Apply the wire mesh on the surface and bind it to the surface using reinforcements.

4) Now apply the second layer of the shortcrete on the surface.


Following figures are used to provide structural visualization for VASANT VIHAR METRO STATION to help in subsequent topics.

BASE SLAB

CONCOURSE SLAB

ROOF SLAB

D

SECTIONAL FRONT VIEW


After excavation we will further study about the bottom-up construction in the

sequence of slabs.

2. SLABS

BASE SLAB-

The major work of the base slab is to support the tracks and resist the vertical pressure

from the ground. The construction process to construct this slab is also the same as the

roof slab and the concourse slab. The base slab is placed 6.86 meters below the base of

concourse slab and it is 900mm thick. The base slab structure is not flat but in shape of a

bucket with leaves at the ends.

For the construction of the base slab this soil is then lined with 75mm (min) thick PCC

layer and 3mm thick ply. These ply act as a base support for the concrete layer; it also

gives a fine finish. As shown in the above figure

BUCKET-LEAF STRUCTURE OF BASE SLAB


MATERIALS USED

-Concrete conforming to M40 grade shall be used for casting.

-Reinforcement conforming to FE500D shall be used on site.

-Water shall conform to IS456.

-Water Stops –PVC water stop will be used to arrest the water leakage as specified in the

drawing.

-Binding wire used for binding reinforcement has a core dia of 1.25mm

-Formwork panel would be made of film coated plywood.12mm thick and shall be placed

along the alignment and the verticality, fine and level shall be checked.

-Cover blocks should be used depending on clearance that needs to be provided to the

reinforcement.

-Minimum lift period for the formwork are as follows-

-Vibrator of 60mm dia 4NOS

Type of Formwork Minimum Period Before

Striking Formwork

a) Vertical formwork to columns, walls , beams 16-24 hours

b) Soffit formwork to slabs (Props to be refixed

immediately after removal of formwork)

3 days

c) Soffit formwork to beams (Props to be refixed


7 days

d) Props to slabs:

1. Spanning up to 4.5 m

2. Spanning over 4.5 m

7 days

14 days

e) Props to beams and arches:

1. Spanning up to 6m

14 days


2. Spanning over 6m 21 days

CONCRETING

-Before concreting the pore are shall be

cleaned using a boom pressure with air or

water.

-M40 grade of concrete shall be used along

with waterproofing admixture of

crystalline type which would be mixed

with the concrete at the batching plant

during mixing.

-Concreting temperature shall be between 32 deg Celsius to 5deg Celsius and concrete shall

be placed using boom placer/bucket whoever serves the purpose.

-In order to avoid cold joints the concrete shall be placed in continuous layers not exceeding

300mm and it should be kept in mind to compact each layer efficiently and completely by

immersion of vibrators before second layer is laid down

-Reason for cold joints-Cold joints are formed primarily between two batches of concrete

where the delivery and placement of the second batch has been delayed and the initial placed

and compacted concrete has started to set. The full knitting together of the two batches of

concrete under vibration to form a homogeneous mass is therefore not possible, unlike the

compaction of two fresh workable batches of concrete. This could be a potential plane of

weakness.

Remedy for cold joints-Proper compaction of the layer beneath and subsequent poring of

second layer without any delay so that the layer below is still green (FRESH).

COLD JOINT BW 2 Layers


COMPACTION

The concrete shall be compacted before the initial setting of the concrete has started.

Immersion vibrators shall be used for the compaction of concrete and the immersion

vibrators shall be used in a near vertical position and shall penetrate the full depth of the

layer of concrete and just in to the layer below as shown in the above figure. Vibration shall

be done continuously until the expulsion of air has practically ceased and in manner which

does not promote segregation of the ingredients. The vibrator shall not be allow to come into

contact with the reinforcement and formwork. Screed vibrators may be used for vibration of

the surface Screed vibrators are very useful for smooth finish and compaction of green

concrete preventing the formation of thermal crack on the top layer.

The pour sequence for concrete adopted is shown below in the figure and should be followed

strictly.

Needle Vibrators Being used at Site


CURING

After the final set has taken place wet hessian cloth shall be placed and covered by polythene

sheet. The hessian cloth shall be kept permanently damp

-After 24Hours hessian cloth and the polythene sheet shall be removed and the area would be

ponded with water .For vertical curing the hessian cloth along with polythene sheet shall

secure the surface for at least 7 days before next vertical pouring begins. The hessian cloth

should be damp all the time.

MIX DESIGN OF CONCRETE (M-40)

MATERIAL QUANTIY(KG) TYPE

CEMENT 380 ULTRA TECH(OPC 53 GRADE)

FLYASH 80 Ashtech:IS3812(NTPC BADARPUR)

AGGREGATE(10mm) 481 Kotpulti


RIVER SAND 677 Yamuna Nagar

W/C RATIO .35

ADMIXTURE @ .85% 3.91 Glenium 147,Suretec(BASF)

W/P CAMPOunds@1% 4.6 MasterPel 760(BASF)

WATER 161 R.O Water at Batching Plant

CURING OF ROOF SLAB UNDER WAY


CONCOURSE SLAB

Outlook of the station is said to be concourse slab. The activities at the station other than the

train tracks are all available on this slab. The slab serves as the gallery of the metro station. It

contains the entry and exit gates to the station, the ticket counters, and security and fire

escape provisions. The construction of the concourse slab is carried out in the same manner

as the roof slab. This slab contains larger temporary cut- outs than the roof slab. These cut-

out spaces help in the laying and development of the base slab and lowering of TBM for

tunneling. These cut-outs are closed during the final phase of the construction. These cutouts

are initially supported by beams to provide stability to the D-walls. These beams are

removed after the structure is stabilized by the construction of the base slab. The concourse

slab is placed 5.25m below the base of the roof slab. Its thickness is 550mm. The concourse

slab contains exhaust vents (Over Track Exhaust ducts) at the sides of the slab. The

concourse slab contains the cavity provided to place the service lines inside the station. The

concourse slab is connected to the base slab with the help of stair case, escalator and lift.

MATERIALS USED

-Concrete conforming to M40 grade shall be used for casting.

CONCOURSE SLAB/ INTERMEDIATE SLAB


-Reinforcement conforming to FE500D shall be used on site.

-Water shall conform to IS456.

-Water Stops –PVC water stop will be used to arrest the water leakage as specified in the

drawing.

-Binding wire used for binding reinforcement has a core dia of 1.25mm

-Formwork panel would be made of film coated plywood.12mm thick and shall be placed

along the alignment and the verticality, fine and level shall be checked.

-Cover blocks should be used depending on clearance that needs to be provided to the

reinforcement.

-Minimum lift period for the formwork are as follows

Type of Formwork Minimum Period Before

Striking Formwork

f) Vertical formwork to columns, walls , beams 16-24 hours

g) Soffit formwork to slabs (Props to be re fixed


3 days

h) Soffit formwork to beams (Props to be re fixed


7 days

i) Props to slabs:

3. Spanning up to 4.5 m

4. Spanning over 4.5 m

7 days

14 days

j) Props to beams and arches:

3. Spanning up to 6m

4. Spanning over 6m

14 days

21 days


FORMWORK & STAGING

Formwork shall provide concrete of the shape, lines and dimensions shown on the drawing.

L&T Formwork System would be used for staging & formwork preparation as per the

approved drawing

For staging purpose Heavy Duty Towers shall be erected and fixed at positions and spacing

as per the drawing with bracing as required to prevent lateral tilting. Such an arrangement

would provide sufficient strength, support and rigidity during placing and compacting of

concrete.

As per the drawing, the top tower spindle of the HDT would be attached to U-head. U-head

will provide a resting platform to the steel waler at 100mm back to back spacing, which

would run along the span of the slab. Over the steel waler, H-16 would be laid

perpendicularly at 300 mm c/c. The steel waler will act as the primary span member &

timber H-beams would act as secondary beam members. Over this, plywood of 12 mm

thickness shall be fixed. Slab will rest over this arrangement.

Formwork will be placed along the alignment and the verticality, line and level shall be

checked. Appropriate formwork arrangement shall be provided at the cut-out portions of the

slab as per the drawing.

Inserts, if any to be fixed within the shutter shall be fixed as per the design and drawing.

The verticality of side shutter shall be checked using Plumb bob.

The straight line of the shutters shall be checked with the help of line thread/ total station.

Starter shutter for RCC wall above concourse slab shall also be fixed.

TEMPORARY SUPPORT TO CONCOURSE SLAB

At per the locations mentioned in drawing composite steel structure would be provided to

give temporary support to the roof slab beam. As the locations of the permanent columns lie

in the cut-out portion of the station, hence for temporary support temporary columns would

be provided.

Three sections of UC 610 x 229 x 125.1 mm shall be butt welded & fabricated (as mentioned

in the drawing) as a single vertical member of length as mentioned in the drawing. Towards


the bottom side of the fabricated column head plate of 32mm thickness MS plate of size 660

x 775 mm will be welded. Similarly, base plate will be welded on the bottom end.

This set up will be lowered through the cut-out portion of the slab above and then positioned

into its place. After positioning it, it will be erected as such the top of the column is pressed

up against the top sab and the gap created in the bottom will be then grouted by prepacked

high early strength non-shrink grout which will give strength of 40 Mpa at the end of 28

days.

Towards the shorter dimension of the column, diagonal lacing at 458 mm spacing c/c would

be provided using ISA 75 x 75 x 6 mm. It will be welded as mentioned in the drawing. 12

mm thick stiffeners will be provided and welded as shown in the drawing.

-As in Base slab cold joints should be avoided, follow the procedure mentioned in base slab.

-Pouring sequence for concrete in concourse slab is as follows-

-Compaction and curing procedure same as base slab.

-Placement of water bar in construction joint should be as follow


ROOF SLAB

The base slab supports the whole weight of the station. The diaphragm walls of the station

sustain huge amounts of lateral pressure from the backfill. This makes the diaphragm wall

act as a cantilever and it tends to lean inwards, but to sustain the pressure the roof slab is

constructed. The roof slab provides the support at one point. The concourse slab built after

the roof slab provides extra support to the D-wall. When the roof slab is constructed, it

completes the box structure and provides additional support and gives stability to the

structure, the roof slab is designed to take the weight of filling and any subsequent structure

that may be built on it. At the time of making of roof slab, several cut-outs are left for further

excavation required for construction of concourse and base slab and for lowering of TBM for

tunneling. The thickness of roof slab is 1.8- 2 meters.

Material required- Same as above

And all other considerations are same as those of base slab and concourse slab. Except that

water proofing has to provide over roof slab, which has been discussed later in the project.

3) WALL

ROOF SLAB SATELLITE VIEW WITH CUT OUTS IN THE ROOF SLAB

CONCRETING ON SITE

CONCRETING ON SITE

DESIGN MIX M-40

M30 would have been suitable according to the load consideration but M40 was used to fulfill the

criteria of design life of 125 years and provide a more sustainable structure.

FOLLOWING ADMIXTURES WERE USED IN THE MIX

1) Masterglenium 147 provides

Description

Polycarboxylic Ether Based High Range Water Reducer / Versatile Super plasticizer Concrete

Admixture.

Masterglenium 147 provides

Extended workability

Providing the ultimate high strength, especially ready

Advantages

Highest quality available with or without pump on site.

MATERIAL QUANTIY(KG) TYPE CEMENT 380 ULTRA TECH(OPC 53 GRADE) FLYASH 80 Ashtech:IS3812(NTPC

BADARPUR) AGGREGATE(10mm) 481 Kotpulti AGGREGATE(20mm) 666 Kotpulti RIVER SAND 677 Yamuna Nagar W/C RATIO .35 ADMIXTURE @ .85% 3.91 Glenium 147,Suretec(BASF) W/P CAMPOunds@1% 4.6 MasterPel 760(BASF) WATER 161 R.O Water at Batching Plant

CONCRETING ON SITE

Favors reinforced concrete elements easy to place & has Self-Compacting Concrete properties.

Allows the provision of maintaining the quality of concrete without losing consistency,

affordable, low water / cement ratio concrete.

Using a single product for many applications.

Application Method

Add to the mixture 80% -90% of the calculated water for the concrete mix and then, with the

remaining water masterglenium 147 must be added to the mixture.

For the efficient dispersion of mastergenium 147 give 100sec or the calculated laboratory time

should be given to mixture with the constant stirring.

Dosage

The use ratio from 0.8 to 1.5 kg is recommended. Depending on the use of laboratory

experiments.

Shelf Life: 12 months from the production date

2) MasterPEL760

Description- MasterPel 760 is a crystalline powder admixture for concrete to achieve high resistance to

water ingression. Free Flowing grey powder with a bulk density of 1.350 ± 0.02 gm/cm3 and is

approved by IS:2645-2003. MasterPel 760 is available in 5 Kg & 25 kg pack.

HOW IT WORKS?

CONCRETING ON SITE

It is based on a blend of Portland cement, processed silica sand and special catalytic agents which

converts hydration by-products to solid crystalline formation in the water transporting capillary tracts

and hydration pores thus preventing water seepage.

Shelf Life: 6 months after date of production

Where it should be used?

MasterPel 760 should be used in all structural concrete that is constantly or intermittently in contact with

water such as

Sea walls

Tunnels

Basements

Structural and pre-cast concrete.

ADVNTAGES

Provides resistance to water penetration either under hydrostatic pressure or capillary absorption.

Imparts integral water tightness to structures

Protects from waterborne corrosive agents.

Permanently active - crystalline action is reactivated by contact with water.

Equally effective against both positive and negative water pressure or osmotic pressure.

Reduced sulfate attack.

Reduced efflorescence.

Do not reduce compressive strengths

Powder – easy to use in pre-batched renders.

Low dosage – Economical

Important points to remember

Ensure water / cement ratio is less than 0.5 .Addition of good plasticizer from the

MasterRheobuild or MasterGlenium range is advised to achieve minimum water/cement ratio.

Place concrete quickly and compact it well.

Ensure complete curing with a MasterKure curing compound.

CONCRETING ON SITE

APPLICATION

MasterPel 760 is a ready-to-use powder which is dispensed into the concrete together with the cement.

Following sequence of mixing shall enable best performing waterproofing mix:

1. Batch course aggregates.

2. Batch fine aggregates.

3. Batch cement & mineral admixtures.

4. Sprinkle MasterPel 760.

5. Dry mix for 1 to 2 minutes to achieve even.

6. Dry mixture.

IN CASE OF BATCHING PLANT (PRESENT CASE)

In case of addition at the batching plant, use a 5Kg (USED 4.6KG) Dosage per cubic meter and add

separately After introducing all other mix ingredients in the mixer and ensure uniform mixing.

MATERIAL QUANTIY(KG) TYPE

CEMENT 410 ULTRA TECH(OPC 53 GRADE)

MICRO SILICA 22 TAM CEM



RIVER SAND 765 Yamuna Nagar

W/C RATIO .37

ADMIXTURE @ .85% 2.16 Glenium sky 777

WATER 151 R.O Water at Batching Plant

CONCRETING ON SITE

DESIGN MIX M50

IMPORTANT CONSTITUENTS

GLENIUM SKY 777

MasterGlenium SKY 8777 is the super plasticizer based on second generation polycarboxylic ether

polymers, developed using nano-technology. The product has been primarily developed for applications

in high performance ready-mix concrete to facilitate TOTAL CONCRETE PERFORMANCE. It helps

to produce high performance concrete with longer workability retention, and high early strength. Mostly

compatible with all OPC, PPC, PSC and can be used with high pozzolonic material.

TOTAL CONCRETE PERFORMANCE- Ensures that ready-mix producers, contractors and engineers

get a concrete that is of the same high quality as originally specified; starting from production at the

batching plant, to the delivery and application into place and followed by its hardening process.

Utilising. Rheodynamic Concrete technology, it provides a concrete mix with exceptional placing

characteristics and accelerated cement hydration for early strength development and high-quality

Concrete.

CONCRETING ON SITE

ADVANTAGES

Capability of delivering high quality concrete at any time to the job site in place.

Production of concrete with low w/c ratio that meets international guidelines for consistency

classes (EN 206-1) without loss of workability.

Single product for many application needs.

MICRO SILICA (TamCem)

TamCem Micro Silica is composed of silicon dioxide (5i02).Collected from silicon metal and

ferrosilicon. TamCem Micro Silica will react with the Calcium Hydroxide from the cement, which will

form more of the Calcium Silicate hydrate, increasing the strength of the concrete. Using Tamcem

Micro Silica will also increase the durability of the concrete.

ADVANTAGES

Precast usage

Produces high early and higher ultimate compressive strengths

Eliminates steam curing, saving on heating costs.

Shotcrete usage

Less material wastage and greater efficiency of product use.

High impermeability and significantly less rebound loss.

Protects reinforcing steel from corrosion. Improved bonding strength.

Thicker applications with each nozzle pass and enhanced pump ability.

APPLICATIONS

High performance concrete.

Precast concrete.

Spray applied concrete.

CONCRETING ON SITE

Concrete exposed to environmental and chemical attack.

Marine concrete.

Ready mix concrete for high strength concrete.

DESIGN PROCEDURE FOR M50

Design stipulations for proportioning

Grade designation : M50

Type of cement : OPC 53 grade confirming to IS 12269

Maximum nominal size of aggregates : 20 mm

Minimum cement content : 320 kg/m3

Maximum water cement ratio : 0.45

Workability : 90-130 after 30 to 120 Minutes

Exposure condition : MODERATE

Method of concrete placing : Pumping

Degree of supervision : Good

Type of aggregate : Crushed angular aggregate

Maximum cement content : 450 kg/m3

Chemical admixture type : Super plasticizer

TEST DATA FOR MATERIALS

COARSE AGGREGATES

1) LOCATION- KOTPUTLI(HARYANA).

2) SPECIFIC GRAVITY -2.74(20MM) & 2.74(10MM)

3) WATER ABSORPTION-.27%(20MM)&2.74(20MM)

4) SIEVE ANALYSIS

SIEVE SIZE(MM) PERCENTAGE PASSING

FRACTION 1 FRACTION 2

20MM 10MM

40 100 100

CONCRETING ON SITE

20 96.1 100

10 6.4 86.4

4.75 .7 11.1

2.36 - .3

FINE AGGREGATE

1) LOCATION-YAMUNA NAGAR

2) SPECIFIC GRAVITY-2.64

3) WATER ABSORPTION-1.02%

4) SIEVE ANALYSIS

TARGET STRENGTH FOR MIX PROPORTIONING

f’ck = fck + 1.65 s

Where

f’ck = Target average compressive strength at 28 days,

fck = Characteristic compressive strength at 28 days

s= Standard deviation

SIEVE SIZE(MM) PERCENTAGE PASSING

(%)

10 100

4.75 94.15

2.34 84.02

1.18 71.05

600 54.57

300 21.76

150 1.24

CONCRETING ON SITE

From Table 1 standard deviation, s = 5 N/mm

Therefore target strength = 50 + 1.65 x 5 = 58.25

N/mm2

2) SELECTION OF WATER CEMENT RATIO

From table 5 IS456:200 the max water content for M40

is =.40 so based on experience adopt a water content of

.35 and 0.35<.0.40

3) SELECTION OF WATER AND SAND CONTENT

Trials were conducted with 41% sand content and 59% coarse aggregate content to get the good

cohesive mix and water contents 151 lts/cum as we are using admixtures to get the required

workability.

4) DETERMINATION OF

CEMENT CONTENT

Water content ratio - 0.35

Water -151lts

Cement Content -410Kgs

M silica -22Kg

SG Cement-3.15

CONCRETING ON SITE

5) DETERMINATION OF COARSE AND FINE AGGREGATE CONTENT(IS:10262-2009)

Volume of concrete = 1 m3

Volume of cement= 410/3.15*1000= 0.135 m3 (a)

Volume of water= 151/1000= 0.151m3 (b)

Total volume of aggregates(CA+FA)= 1 - (a + b) = 1-(.135+.151)= 0.714m3

Volume of coarse aggregates= 0.714 * 0.59* 2.74 *1000= 1154kg.

Volume of Fine

aggregates=.714* 0.41*2.64*

1000= 773kg.

Slump Value for the MIX

CONCRETING ACTIVITIES ON SITE

Any concreting activity on site happens in the following sequence.

Pouring plan

Before proceeding with concrete pouring plan to be prepared which shows

How concrete is to be done?

In how many layers?

Where is the positioning of concrete equipment like boom placer, Concrete pump?

TIME

SLUMP

(MM)

INITIAL 180

60Min 150

90 MIN 125

120MIN 110

CONCRETING ON SITE

Standby arrangements?

Time Management is the key factor for a successful pouring operation. Pour cards are prepared for

effective and efficient pouring operation.

Compaction of concrete

Compaction is the process which expels entrapped air from freshly placed concrete and packs the

aggregate particles together so as to increase the density of concrete.

It increases significantly the ultimate strength of concrete and enhances the bond with reinforcement. It

also increases the abrasion resistance and general durability of the concrete, decreases the permeability

and helps to minimize its shrinkage-and-creep characteristics.

ON SITE-Vertical Vibration using needle vibrators was done.

The time of application of application of vibration at a location is from 5-10 sec.

Vibrator should be at least 150mm into the layer.

Over vibration can lead to segregation so sharp monitoring of workman is required.

When proper vibration is done he probability of getting a cold joint reduces and high strength

RCC is obtained.

Finishing

Concrete finishing should be done after concrete immediately but no need to smooth finishing

on surface to avoid minor cracks.

Curing Of Concrete

After final set has taken place wet hessian cloth shall be placed and covered by polythene sheet.

The hessian cloth shall be kept permanently damp.

After 24 hours hessian cloth and polythene sheet shall be removed.

CONCRETING ON SITE

The area shall be ponded for 7 days.

Defects encountered on site and repair techniques used

BULGED CONCRETE

Bulged Concrete – Bulging in concrete takes place due to displacement of formwork.

Surface preparation: The bulged area on concrete surface shall be hacked with chisel to required line, level. All dirt, dust shall be cleaned with brush and water.

Repairing: Hacked area will be patched up with cement: sand mortar of proportion 1:4. On the completion of patch up work, the exposed area shall be thoroughly cured.

Grout Loss Exposed aggregate surface created by exit of cement slurry/grout mortar from the gaps of formwork due to excessive vibration, unsealed joint of formwork during pouring of concrete. Repair

The concrete surface is cleaned and free from dust/oil/grease etc by using broom or wire mesh by scrubbing vigorously.

After removal of loose particles surface is washed with water.

Patch-up is done at cleaned surface with non-shrink Grout conbextra GP2 (Fosroc)/

Rendroc RG (Fosroc)/ Concressive 2200 (BASF)/Emaco S88CT. The material mixing shall be as per manufacturer recommendation. On the completion of patch up work exposed area shall be thoroughly cured.

CONCRETING ON SITE

Honey Combing It is due segregation of aggregates and mortar into the concrete. Honeycomb creates in structures due to mainly improper compaction in terms of excessive/insufficient vibration at the time of placing of concrete or several grout loss. Types

Minor Honeycombing Minor honeycomb is those which create small void within the cover of reinforcement.

Major Honey combing Major honeycomb is those defects which extend beyond the reinforcement bar and create big void on the surface.

Repair Surface Preparation The loose aggregate that are exposed shall be removed by gently tapping on it. After removal of all loose aggregate, dust, dirt etc. by wire/Soft brush then surface will be cleaned with Water. Patchup is done by using conbextra GP2/Rendroc RG/Concressive 2200/Emaco S46 T/Masterflow 918 or mix prepared at site as per site mix design on the cleaned surface with non-Shrink material. The material mixing shall be as per manufacturer recommendation. On completion of the patchup work, exposed area is thoroughly cured.

CONCRETING ON SITE

Exposed Reinforcement Bar Reinforcement bars exposed is mainly due to improper/insufficient cover block placement at the time of fixing of reinforcement bars, loose formwork erection (Mortar flows through the gap of formwork). Repair Surface Preparation- Concrete is chipped off up to 25mm behind the reinforcement for the area where there is exposure of reinforcement bars takes place. Remove all loose particle, dust etc with clean water. The exposed rebar is treated by coating with cement slurry.

The patch-up work is carried out using non shrink grout conbextra GP2/Concresive 1315/Sika Injectocem-190/Emaco S46 T or as per prepared site mix design. The material mixing shall be as per manufacturer recommendation. The finishing of surface is beyond the reinforcement forming a smooth curvature. On the completion of patch work, the repaired area is thoroughly cured

Concreting Operation in Hot Weather

While hot weather conditions are commonly encountered in summer, combinations of High ambient temperatures & Low relative humidity could result in conditions leading to problems with concrete placement and finishing at any time during HOT WEATHER.

Following points must be followed to ensure good concreting operations during hot weather conditions.

PLANNING

Planning should be done before hand of the operation with proper estimation of quantity and surface should be prepared for concreting operation.

-Concrete supply should be continuous without any delays.

-Standby machinery and additional manpower must be present on site.

CONCRETING ON SITE

-Slump of value of each batch of concrete should be checked before placing.

Concrete production also plays an important role in case of hot weather concreting and following points

should always be kept under consideration.

-Shade should be used over the stockpile of aggregates

-Paint the mixer and storage bins white to minimize absorption of heat from the sun.

-Use ice as part of the mix water or cool the concrete with liquid nitrogen

DELIVERY AND DISCHARGE

-Transportation time should be minimized and transportation should be preferred during the time period when the intensity of traffic is less.

-Avoid prolonged mixing. Transit mixer trucks should be discharged as soon as possible after the water has been added to the mix.

-Consider batching and mixing the materials using a job-site plant.

CONCRETE POUR CARD (A DOCUMENT USED FOR KEEPING A CHECK

ON QUANTITY AND PROPERTIES OF CONCRETE COMING ON SITE)

CONCRETING ON SITE

-Water should not be added to concrete at the job site unless it is part of the amount required initially for the specified maximum water-cement ratio and the specified slump.

PLACING AND FINISHING

-Schedule placement for the cool time of the day

-Equipment and workers ready to receive and handle concrete, especially the first delivery.

-Use sunshades and/or windbreaks.

-Keep all equipment that are in contact with the concrete cool ( pump lines, tremies, reinforcement and vehicles ).

-Use low temperature water or ice to reduce the temperature in TM(Transit Mixer).

-Use a thermometer to monitor the temperature.

-Shorten finishing time.

EVAPORATION CONTROL

-Be alert in eliminating the damaging practice of ‘wet wiping’ or spraying water onto the dry patches

during trowelling of the concrete Significantly reduces surface crusting.

-A dry surface layer may appear to indicate that the concrete has set, but can lead to a ‘spongy concrete’

effect, as the concrete below is still plastic. This may result in flaking and an uneven surface finish.

CURING AND PROTECTION

CONCRETE REQUEST SLIP (A DOCUMENT USED FOR PLACING A

REQUEST FOR CONCRETE TO A BATCHING PLANT)

CONCRETING ON SITE

-Curing should start immediately after the CONCTERE has been finished.

-Curing methods include PONDING WITH WATER, use of WET HESSIAN or COTTON MATS, continuous spray mist, covering with PLASTIC SHEETING or sprayed on CURING COMPOUNDS.

DESIGN SPECIFICATIONS FOR STRUCTURE

1

Design life of the structure

The design life of a structure is that period for which it is designed to fulfil its intended

function when inspected and maintained in accordance with agreed procedures. The

assumption of a design life for a structure or component does not necessarily mean that the

structure will no longer be fit for its purpose at the end of that period. Neither will it

necessarily continue to be serviceable for that length of time without adequate and regular

inspection nor shall routine maintenance. All Design Life criteria be confirmed.

Underground civil structures -120 yrs.

Above ground building structures -50 yrs.

Asphaltic pavements -15 yrs.

Concrete pavement -25 yrs.

Tunnel Walkways -20 yrs.

Steel Paintwork Systems -05 yrs.

Nonstructural components -30 yrs.

Waterproofing membrane -10 yrs.

Steps to be taken to ensure a design life of 12yrs for the structure are-

Use of Micro Silica conforming to Is15388:2003(or other suitable admixtures)

Water permeability should not exceed 10mm

Rcpt (RAPID CHLORIDE PERMEABILITY TEST)-Value should be less than

1000coulombs

Minimum Cement content for underwater structure per M3 should not be less than

400kg.

Contractor should further submit a report in context to design, construction &material

so as to achieve 120 years of design life.


2

RCPT TESTING

Corrosion of reinforcing steel due to chloride ingress is one of the most common

environmental attacks that lead to the deterioration of concrete structures. Corrosion related

damage to concrete structures is a major problem. This durability problem has received

widespread attention in recent years because of its frequent occurrence and the associated

high cost of repairs. Based on the charge that passes through the sample, a qualitative rating

is made of the concrete’s permeability.

Design Loads and Calculations

Railway Load

The railway loadings considered are as per “Modern Rolling Stock” type with following axle

configuration. However loading due to rolling stock can be modified after the proposed

rolling stock has been finalized.

For the purpose of computing stresses and deformations the following loads and

consequential effects shall be taken into account.

• Dead loads DL

• Live loads LL

• Dynamic effects Dl

• Forces due to curvature or eccentricity of track CF

• Temperature effects T

• Longitudinal forces LF

• Racking forces RE


3

• Forces on parapets

• Wind pressure effect WL

• Earth Pressure EP

• Water Pressure WP

• Forces and effect due to earthquake EQ

• Erection forces and effects DEL

• Buoyancy B

• Differential settlement DS

Modern Rolling Stock Loading

2A= 2250 + 2B= 2500 + C=12600 = 22100mm

Design load shall include the effect of

Static Loading These shall consist of loads due to:

Track: Load due to 60 Kg (UIC) rails and guard rail and fittings

Track bed: RCC blocks or concrete pour or precast slabs in RCC with inserts and

finings. In case of ballast less track (450 to 600 mm thick) or PSC sleepers over

250/300 mm thick for ballasted track.

Fatigue Loading

Those structures subjected to repeated fluctuations of stress. These fluctuations

may cause fatigue failure of members or connections at lower stresses than those

at which they would fail under static load. Such failures are primarily due to stress


4

concentrations introduced by the constructional details. To overcome such

problems the concept fatigue loading is employed.

The nominal loading for the design of members in accordance with BS 5400: Part

10 shall comprise trains with six individual cars each having four axles.

Dynamic Loading

When live loads are applied rapidly to a structure, they cause larger stresses than

those that would be produced if the same loads would have been applied gradually.

This dynamic effect of the load is referred to as impact. Live loads expected to cause

such a dynamic effect on structures are increased by impact factors.

Coefficient of Dynamic impact (CDA): Impact factor for longitudinal analysis shall

be 1.2 while for transverse analysis the same shall be 1.67. Dynamic loading shall not

be applied to piles, pile caps. Centrifugal loads or braking/traction loads.

Longitudinal Loading

It acts due to braking of large trucks or trains on bridges, ships entering a harbor or

cranes on a rail.

Longitudinal loads from braking and traction shall be 18% and 20% of live load per

track. When a structure carries two tracks, both tracks shall be considered to be

occupied simultaneously. Traction forces shall act on one track and braking forces

acting on the other, with both acting in the same direction simultaneously to produce

the worst loading condition

Centrifugal load

Train Derailment Load: For tracks on a curve, centrifugal force (CF) shall be considered as a

horizontal load applied toward the outside of the curve above top of rail. The centrifugal

force (CF) is a function of the train live load, impact (I), and horizontal radius of curvature:

As per latest Design Code ACI 358.1R-92, for derailment check, derailment load corresponds

to the application of 50% of one coach weight, applied horizontally as a 5m long uniform

Impact load.

Wind loading


5

WL will be applied to above ground structures. Calculation of Wind Load is based on IS-875

(Pad 3) - 1987.

The minimum design wind pressure to be used is: pz = 609 kN/m2

Temperature Loading – (Not Used).

Seismic Loading

Seismic effects shall be considered on all structures. Other details for seismic design shall

conform with IS 1893 and other guidelines obtained after soil testing and study.

DELHI is located in ZONE 4(HIGH RISK ZONE) according to Seismic studies.

IMPORTANCE

FACTOR (I):It is a

factor used to obtain the

design seismic force

depending on the

functional use of the

structure, characterized

by hazardous

consequences of its

failure, its post-

earthquake functional

need, historic value, or

economic importance.

STRUCTURAL RESPONSE FACTOR (Sa/g): It is a factor denoting the acceleration

response spectrum of the structure subjected to earthquake ground vibrations, and depends on

natural period of vibration and damping of the structure.


6

ZONE FACTOR Z: It is a factor to obtain the design spectrum depending on the perceived

maximum seismic risk characterized by Maximum Considered Earthquake (MCE) in the

zone in which the structure is located. The basic zone factors included in this standard are

reasonable estimate of effective peak ground acceleration.

Response Reduction Factor (R): It is the factor by which the actual base shear force that

would be generated if the structure were to remain elastic during its response to the Design

Basis Earthquake (DBE) shaking, shall be reduced to obtain the design lateral force. Taken as

4.

For all buried structures an incremental dynamic load should be applied. For the

purposes of implementing this method a design seismic coefficient of (Ah) 0.1125 shall be

adopted at ground Level linearly reducing to 0.056 at 30 m depth as permitted by.

These coefficients already include the Importance Factor of 1.5 required.

NOTE-Based on the performance record, it is undoubtedly fair to say that underground

structures are less vulnerable to earthquakes than surface structures

Temporary elements such as scaffolding, temporary excavations need not be designed for

earthquake forces.

EARTHQUAKE DEFINATIONS:

OPERATIONAL DESIGN EARTHQUAKE (ODE): The earthquake for which a structure is

designed to remain operational, with the damage being readily repairable following the event.

The ODE/OLE is likely to occur during the design life of the structure. Based on probabilistic

methods, and is generally the 50%/50 year earthquake motion.

Controlling Earthquake or Maximum Design Earthquake (MDE): The earthquake that is

expected to produce the strongest level of shaking at a site. Often used interchangeably with

MCE (above), but is based on ground motions, not earthquake size. The MDE can be based

on deterministic or probabilistic methods. For critical structures, the MDE may equal the

MCE from a specific fault or seismic source.

Effect of earthquake on above ground and underground structures.


7

Above Ground Under Ground

Above ground structures need to transmit the seismic forces towards the foundation since soil is not available on sides.

Design becomes uneconomical when approach is centered towards designing structure for MDE

Surface structures are not only directly subjected to the excitations of the ground.

Comparatively lower redundancy to earthquakes.

For aboveground structures, the seismic loads are largely expressed in terms of inertial forces

Underground structures, such as underground stations, subjected to seismic actions don´t need to transfer inertia forces to the foundations, since those forces are directly transferred to the surrounding soil.

Feasible though not recommended to design for MDE

Directly subjected to shaking of ground due to transfer from surrounding soil strata.

Shows greater redundancy towards earthquake

The design and analysis for underground structures should be based, however, on an approach that focuses on the displacement/deformation aspects of the ground and the structures

Operating Design Earthquake (ODE). For the ODE, the seismic design loading combination depends on the performance requirements of the structural members. Generally speaking, if the members are to experience little to no damage during the lower level event (ODE), the inelastic deformations in the structure members should be kept low.

GENERAL INSTRUMENTS USED ON CONSTRUCTION SITE

1

INSTRUMENTS USED ON SITE

Tiltmeter

A Tiltmeter is an instrument designed to measure very small changes from the vertical level, either on the ground or in structures

A similar term, in less common usage, is the inclinometer. A sensitive instrument can detect changes of as little as one arc second. It consists of

tilt plates, a portable tilt meter & a readout unit

USED AT SITE- Used on Buildings around Vasant Vihar Station.

Frequency of taking the readings

The frequency of taking the readings of instruments is twice a day.


2

Building settlement, ground settlement & optical survey readings are taken by surveyors.

Inclinometer, Tiltmeter, Tape Extensometer, Crack meter, Load Cell & Piezometer readings are taken by Instrument-Rite Engineers.

CRACKMETER

It is used to monitor cracks in buildings affected due to construction or excavation activities.

It is installed by drilling 5mm diameter & 50mm deep holes.

USED AT SITE -VASANT VIHAR

ROOF SLAB


3

Tape Extensometer It is used to measure small changes in distance between two reference points

in any orientation

To give deformation of underground openings, excavations, tunnels,

movement of unstable slopes etc.

The tape extensometer forms an

important part in investigations during tunnelling,

especially the New Austrian Tunnelling Method

(NATM) for effectiveness of the roof of a

underground cavity and monitor its behavior during

the excavation operation.

HOW IT WORKS??

o To obtain distance reading

between pair of reference anchor bolts grouted into

any structure, the operator is required to stretch the

tape between two anchors, adjust its tension and note the tape and

digital readings. This is not the true distance between the two reference

points. This is only used as an initial reading. The variation from the

initial reading, gives the change in distance (convergence or

divergence) between two anchorage points with a measurement

sensitivity of ± 0.01 mm (± 0.0005”)

USED AT SITE-


4

LOAD CELLS

It is used to measure and monitor load on the struts, which are used for

externally supporting the soil pressure due to excavation.

The load cell is ideally suited for measurement of compressive load or forces.

USE AT SITE-VASANT VIHAR


5

STAND PIPE PEIZOMETER It is used to measure depth of ground water level in standpipes, boreholes &

wells.

The stand pipe Piezometer consists of a pipe that is sealed along its entire

length and installed in a borehole such that it must be open to water flow at

bottom and open to atmosphere at the top.

Ideal for simple ground water monitoring.

HOW IT WORKS?

The stand pipe is set in a bore hole, which is drilled into the soil/foundation to

a pre-determined depth to intercept ground water. The perforated pipe is

connected by a socket to same diameter plastic stand pipe extending to the

surface. The borehole is filled with pea gravel. The top of borehole is

Sealed with cement bentonite plug the Ground water seeps into the stand pipe

Ground water level through the slotted end and attains a level equal to ground

water. This level is determined by an electrical sounding device.


6

GROUND SETTLEMENT POINT It is used to monitor vertical settlement on the ground surface. It is installed by making a pit of 1000mm deep & 500mm square at the top & filled with soil & concrete. The steel bar is kept at the centre of GI pipe.

READINGS

Water Proofing Of Roof Surface

1

WATERPROOFING OF STRUCTURE

In the case of underground concrete structures which are usually surrounded by moisture the

need to keep the water out is critical. Therefore, waterproofing shall be done on roof slab to

ensure water tightness of the structure.

What is water proofing?

Waterproofing is the creation of a relatively impervious membrane, coating, or sealer used in

concealed locations to prevent water from entering or passing through either horizontal or

vertical building materials.

Chemicals used:

FOR PRIMING

Master Emaco 2525 is a solvent free, high-performance, versatile epoxy binder that can be

used to produce a range of epoxy resin based mortars. Master Emaco 2525 can be applied to

both dry and damp surfaces and adheres to most substrates after proper preparation.

Recommended use:

Structural bonding of new to old concrete

Production of epoxy resin mortars for floor toppings

Production of epoxy resin mortars to grout bolt holes

Steel bonding

Rapid structural repair of concrete

Grouting dowels

Priming of concrete floors prior to applying Master top Flooring Systems and

MasterSeal.

Membrane Systems to achieve structural bond


2

Advantages:

Adheres to wet or damp surfaces – Wide application area

solvent free - Low VOC and non-shrink

Pre-proportioned packaging - No job site errors

Multi-purpose binder - Many uses

Low viscosity - Easy to apply as primer

High abrasion and chemical resistance

Can be used as wearing surface Approved to AS/NZS 4020:2002 – Suitable for contact

with Potable Water.

Cures hard at low temperatures – Wide application rang

0Properties of the chemical:

FOR WATER PROOFING

Master Seal M800

Description- A highly elastic, solvent free, ultra-fast curing, spray applied polyurethane

coating and it is used in waterproofing applications. MasterSeal M800 is a solvent free,

two component.

It is highly reactive and can only be applied by special two component spray equipment

Master Seal M800 is used in a variety of waterproofing applications including roofing,

balconies, podium and car park decks, cut and cover tunneling and basement

waterproofing.


3

FEATURES AND BENEFITS

• Easy application to complicated details

• Fast installation

• Can be applied to a wide range of substrates with the appropriate primer

• Monolithic – no welds or seams

• No welding, no torches, no hot works

• High water vapor permeability – low risk of blistering

• Excellent mechanical properties

• Excellent crack bridging properties

• Root resistant

• Resistant to standing water

• Application to vertical surfaces without runs

SUBSTRATE CONDITION

The primer, or base layer to which Master Seal M800 is to be applied must be clean and dry and

free from oil, grease and loose material and any other contamination which might impair

adhesion.

STEP WISE PROCEDURE OF WATER-PROOFING.

SURFACE CONDITIONS

The RCC surface shall be dry before waterproofing.

Any ingress for water seepage shall be identified and treated.

Construction Joint shall be filled with high performance water stop grout of crystalline

growth.


4

The gap between D-wall and slab shall be filled with micro concrete(As shown in

figure)

The concrete shall be fully cured before The surface

shall be cleaned with wire brush to remove all algae, fungus

and voids, pinholes, cracks shall be treated to level and

smoothen the surface are starting of waterproofing works.

MIXING:

Proportion part kits accurately mixing only what can be used in less than 30 minutes.

Thoroughly stir Part A, add Part B (3:1 parts by volume respectively) and blend thoroughly using

a slow speed mixer fitted with a suitable paddle.

MIXING OF COMPONENT A & B


5

Primer Application

Thin coat of mixed primer (RESIN + HARDNER) on the surface shall be mechanically

& uniformly applied, ensuring continuous film soon after surface preparation is

complete.

Moisture content in the substrate shall be less than 5 %.

The drying period of primer depends on the ambient temperature and relative

humidity.

MOISTURE METER BASF AGGREGATES

BASF AGGREGATES are sprinkled over

the primer layer immediately after

application of the primer. Aggregates

help in roughening the surface of

primer for proper bonding between

the primer layer and the

waterproofing membrane layer.

APPLICATION OF PRIMER LAYER

Master seal M800 Being heated to a

temperature of 60 deg Celsius before being

applied using gun.


6

APPLICATION OF WATER PROFFING MEMBRANE

Water proofing membrane shall be applied in double layers such that dry film thickness

of the membrane is minimum of 2.5 mm. The entire 2.5 mm layer shall be single

monolithic layer built in two applications.

MasterSeal M800 can only be applied by means of a suitable two component spray

machine. The choice of machine depends on the type and size of work and the ease of

access.

MasterSeal M800 is available with the Part A coloured white

and the Part B coloured black. This results in a uniform grey colour

of the sprayed material thus giving the sprayer a visual control of

the quality of the mixing, and machine faults become immediately

obvious. If the membrane colour changes, stop spraying and check

machine settings etc

MasterSeal M800 is normally applied at 1.5–2.0kg/SQM this

corresponds to a thickness of 1.5–2.0mm.

APPLICTION OF WATER PROOFING MEMBRANE ON PRIMER LAYER

SPECIAL TWO COMPONENT SPRAY GUN

FOR WATER PROOFING


7

PACKAGING

MasterSeal M800 is supplied in drums.

Component A 210 kg

Component B 220 kg

Mixing ratio

By weight 100:73

By volume 100:70

Requirements on site

Dry Film Thickness – 2.5 mm

Tensile Strength- 4.0 Mpa min

Membrane Elongation at break- 130 % min

Peel Adhesion to concrete – 2 Mpa min

Static crack bridging – 2 mm min

Termination

The setting time for the arrangement is 2-3 seconds

and the surface becomes tack free in 45 Seconds.

Testing

The metallic thickness should not be less than 2.3mm

as shown above it should be checked per 10sqm

Holiday Testing

PONDING(DONE AT SITE)

2.6MM

THCIKNESS OF MEMBRANE


8

Ponding of water shall be done over the roof slab for minimum 72 hours to access

leakage if any from the membrane.

Protective arrangement for waterproofing membrane

The membrane shall be protected with 25 mm thick extruded polystyrene boards, which

shall be spot bonded to the membrane.

A 6-mill polyethylene separating membrane shall then be laid before covering with

protective slab of lean mix of min 75 mm thickness.

Where the roof slab has been cast against a diaphragm or other face, the protective slab

shall be provided with an up stand at the perimeter to provide a min 75 mm concrete

protection.

75mm PCC COVER

6-mill polyethylene

separating membrane

Waterproofing Membrane

25 mm thick extruded

polystyrene boards

STUDY ON PREFABRICATED CONCRETE SEGMENTS & CASTING YARD (MUNDKA)

LOCATION- MUNDKA, New Delhi

Products

Segments for Rings (Tunnel)

OTE(over track extract duct)

List of major equipment’s at site

MATERIAL USED-

CONCRETE-Concrete of grade M50&M40 in accordance with code IS456:2000 shall be used.

S.No Equipment Nos Capacity

1 Batching Plant 1 30cum/hr

2 Transit Mixer 2 6cum

3 Steam Boiler 1 600kg/hr

4 Casting Yard 1

6 Rebar cutting 2 -

7 Gantry crane 2 5T

8 Vacuum lifter 1 -

9 EOT crane 4 10T

10 Office 1 -

11 Reinforcement yard 1

12 QA/QC LAB 1

13 Storage Yard -

1

13

11 10

4

12


REINFORCEMENT-Reinforcement of grade Fe500 shall be used

WATER –Clean water shall be used in preparing concrete. Water shall be free from solid suspended matter and organic matter and should comply with IS456

EMBEDMENT-All embedments should be prepared as per the drawings

CONSTRUCTION PROCEDURE

Rebar Cage Fabrication&Cage placement

All reinforcemnt bending,sutting and fixing activities shall take place within the reinforcement yard

and should be done according to the provided BBS.

The rebars shall then be placed in the jogs as per the spacing and then tack welding should be used at

intersections.

2.55mm welding bars conforming to IS6013 shall be used from the approved list of vendors.

Accepted reinforcement cages shall be tagged with BLUE TAG

Rejected reinforcement cages shall be tagged with RED Tag

Cage shall be placed in to the mould using the gantry crane and spacers should be provided as per the

drawings.


Concrete Batching & Placing

CONCRETE BATCHING

Concrete Shallbe produced from 30cub/batching Plant.All

materials shall be checked and approved and the batching shall be

done by WEIGHT

M50 grade concrete shall be used for preparation od tunnel

segments and M40 for OTE ducts.

Slump testing should be done every day before placing the

concrete into the mould as per IS1199.

Temperatire should be checked regularly of the produced

concrete and chilling systems shoul be used whenever necessary for

bringing down temperature(MAX 32 degree celcius)

Cube samples shall be taken out for 150mm cubes and filling should be done on a vibrating table or

using the tamping rods.

CONCRETE PLACING

Concrete shall be supplied by In-house batching plants and should be transported by Transit Mixer.

The concrete shall be transferred into a crance bucket from transit mixer after all the parameters have

been checked.Bucket shall than be lifted using a

gantry crane over the mould that has to be casted

Concrete shall be discharged by opening the

bucket and the vibrator attached to the bucker and

care shall be taken that the falling height of the

concrete shall be less than 1m.

During hot weather ,additional precautions

should be made to prevent premature setting and loss

ON SITE BATCHING PLANT


of water during the placing and compaction of concrete in the formwork.

Compaction of Concrete

The mould used for placement are equpped with a total of 5 motor operated vibrators

below the bottom (4 corners +1 Middle).These should be used during the time of

filling the concrete along witht the needle vibrators.

Surface Finishing

After the compaction of concrete ,The mould cover shall be opened.Top cover of the

segment shall be worked(PLANED) using a squoare plastic pipe whose width is

equal to the width of the segment.To get the accurate thickness.

EARLY FINISHING Within 30 Minutes of working with the Pipe trowel shall be

used on the surface to avoid the pinholes.

FINAL FINISHING After 2-3 hours of casting,top surface of segments shall be

finished by steel trowel to get very smooth surface.

BEFORE AFTER


Testing Of Concrete

Samples of concrete shall be taken regulary in starting for

7 DAYS-3

28 Days-3

12Hours-2

for every batch however the frequency can be reduced later.Sampls

shall be taken for for both M50 and M40 grade.

In case of failure the sement shall be tagged RED as Rejected.


Checking Of The Moulds

Checking of the mould shall be done using the

following precission tools

Micrometer Gauge-1500mm

Measuring Steel Tape- 30m

Set of shim for reading the gaps.

Angular templates and depth gauges

Application of Steel Mould

Side plates and end plates shall be kept in unfolded

position.

Aplly to coats of release agent(chemical) on the surface

of the mould REEBOL(Forsoc),Rheofinish249W on the surface of the mould .

Place the Prefabricated rebar Cage in the mould and then the side plates of both the sides shall be pushed

towards the base and then fasten them together using lock bolts.

Adjust the radial and longitudnal core rod.Care should be taken while installing the weight lifting arm in

the centre.

Adjust the cover and then pour the concrete.

Concrete shall be placed from farend to centre using bucket and crane.

After initial setting of concrete top cover is removed and extrados in finishing using steel float.

Dimensional checking for mould shall be done once a month and if necessary be re-adjusted

Demoulding procedure

After concrete attains strength of 12Mpa in normal condition,removal

of segment shall be taken up.However for attaining early strength of

concrete steam curing shall be done.

Dismantle the core rod of the side plate.

Dismatle the core rod of the end plate.

Lossen the lock bolt of the end plate and open the end plate by

switching device.


Lft the concrete segment using vacum lifter and placed on stand for minor repais

applicatio if curing campound(EMCROIL-MC Bauchemic Make)And final inspection

before shifting to stck yard.

Cncrete moulds shall be cleaned properly and slag should be cleared neatly.

Steam Curing Procedure(WHY IS IT IMPORTANT)

The development of the strength of concrete is a

function of not only time but also that of

temperature.When concrete is subjected to higher

temperature it accelerates the hydration process

resulting in faster development of strength.Dry heat

cannot be used as presence of moisture is also necessary

for hydration process.Stem curing hence helps in

subjecting the moulds to higher temperature and at the

same time maintaining the required wetness.

However young concrete should not be

subjected to sudden high temperatur as certain amount

of delay is desirable because concrete subjected to

steam curing exhibits a sligthly higher drying shrnkage

and moisture movement.

Steam curing at ordinary pressure is applied

mostly on prefabricated elements .Once the segment concrete undergoes initial setting

after 3 hours the whole mould is covered with tarpaulin system.Companion concrete

mould(SAMPLES) are suitably placed inside the tarpulin.

Steam is admitted into each of the mould by valve system in sych a way that

temperature is raised at the rate of about 20Degree celcius per hour.

Max temperature is kept at about 60 Dgree celcius .

At about 4Hours of steam curing the steam is topped and the segments are allowed to

cool for 2 hours .The companion cube is taken out,de moulded and tested .IF AND

ONLY if the strength of the cube is more than 12Mpa or more the segments are de-

Moulded.

MARKING

Segments are marked suitably with the date of casting,Segment Type and tapered before

stacking

All Marking shall be made on the radial joint face,which can be observed easily a the

area.


The segments which are finally selected for lining are maked with the segment number

while others are rejected.

REPAIR

After inspection repair of segemnts for concrete shall be done accordingly treating

problems like blowholes,sharp edges,chamfered edges etc.

Chamfered edges 5mm-50mm depth and corner edge 5mm-70mm shall be repaired

using high strength cement shrinkage compensated mortar;a bonding agent may be

used if required.

Repair Methods for Minor Surface Defects

1.Corners-Less than 5mm deep-No Repair Required.

2.Blowholes-greater than 2mm

Remove all losse concrete fragments and dusts using wire brush to form a

clean rough and structurally sound concrete.


Pre wet the substarte thoroughly to saturate the pores completely with water

Use sandpaper to smoothen the surface after the repair material has hardened.

3.Corner-5mm to 70mm Deep

Cut back damage periphery edge of spalled segment to a depth of not less than

10mm using disk cutter to form squqre edges on plan.in section,the edge

should be inclined away from the spalled are provide tail key at the repair join

edge.Remove all losse material fragments and apply repair in two layers.

Ring Recesses rapair is as shown in figure

Storage & Handling

After demolding using a vacum lifter the segment should be placed on a prepared surface for repair.

After repairing the segments shal be turned 180 degree with intrados facing upwards by turning device,transported to storage are and stored in a stack,one ring high by gantry crane with sling belt.

Delivery and Transportation

Upon unloading from site the segments shall be checked carefully and if they are damaged during the transportation responsible people shall be notified on site to do repair.

The Transportation is Adviced at NIGHT or at a suitable time when roads are on free run o accommodate the large vehicle.

Each lorry shall tranport 2 rings at a time. As shown in fig


Construction Tolerance Limits. Circumferential Length +3mm-0mm Thickness +5mm-0mm Width +1mm-1mm Internal Diameter of completed ring

+8mm-0mm

Bolt Hole size Position +1mm-0mm

Sketch of steel mould

Application of mould

Open the side plate and end plate of a steel mould to check whether its inner

surface and mating surface are free of rubbish slag. Note: before opening the

steel mould, first loosen the, lock bolts of the side plate and the end plate:

manually open the side plate to the end plate with the switching device km

the end plate

Apply several Coatings of the release agents.

Adjust The reinforcement cage

First of all, Pull the end plates of both sides and the base together by using

the switching device and then fasten them with lock bolts.

Afterwards push the side plates of both sides to the base and then fasten

them together with lock bolts

1 COVER

2 LOCK BOLT

4 POSITIONING PIN

5 GUIDING RAIL(SIDE PLATE)

6 SIDE PLATE

7 FIXED CLAMP INSERT

8 INSERT FOR FITTING

9 LONGITUDNAL MOULD CORE

10 LONGITUDNAL CORE ROD

11 RADIAL MOULD CORE

12 RADIAL CORE ROD

13 END PLATE

14 SWITCHING DEVICE END PLATE

15 LOCKING DEVICE CORE ROD


The lock bolts shall be fastened from the centre of the steel mould to both

sides symmetrically and smoothly.

Adjust the longitudinal core rod.

Adjust the radial core rod

Install the insert for lifting of the weight lifting arm

Adjust the cover

Pour the concrete into the mould.

108

TUNNELING

Tunnels are feasible alternatives to cross a water body or traverse through physical barriers such as

mountains, existing roadways, railroads, or facilities; or to satisfy environmental or ecological

requirements. The tunneling in CC-27 project is taken care by SUCG Infrastructure Pvt. Ltd. There are

different techniques of tunneling viz. drilling and blasting, NATM, hydraulic splitter, slurry shield

machine, etc. All the tunnels in project CC-27 are to be made using TBM. A Tunnel Boring Machine

(TBM), also known as a "mole", is a machine used to excavate tunnels with a circular cross section

through a variety of soil and rock strata. TBMs and associated back-up systems are used to highly

automate the entire tunneling process, reducing tunnelling costs. In certain predominantly urban

applications, tunnel boring is viewed as quick and cost effective alternative to laying surface rails and

roads. Expensive compulsory purchase of buildings and land, with potentially lengthy planning

inquiries, is eliminated.

USE OF TUNNELS BY DMRC

Tunnels & Underground stations were provided due to environmental & space constrains further tunnels

allow for estate developments over them. Underground structures have an added advantage of a longer

structure life as compared to those on ground.

TYPES OF TBM

SINGLE SHIELD TBM:

A single shield machine uses pre-fitted segments to exert the blast force on the working face. Digging

time represents approximately 80% of operating time, the remaining 20% corresponding to segment

fitting.

1) Cutter head

2) Shield 3) Belt conveyor 4)

Excavated material removal

trolley

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DOUBLE SHIELD TBM (USED AT VASANT VIHAR)

Machines allow for faster tunnel excavation as the segments are fitted in concurrent operation time

during blasting (digging). In this case, digging time approaches 100% of operating time. The rear shield

is fitted with grippers.

Machine progress is a 3-step process:

Gripping of the rear shield onto the excavated surfaces,

Digging by the cutter head (front shield advance), and laying of the lining,

Rear shield advance (hence gripper advance) to the next digging position and

1. 1)Cutter head

2. 2)Shields

3. 2a - Front shield

4. 2b - Double shield

5. 2c - Rear shield and gripper

6. 3)Belt conveyor

7. 4)Excavated material removal

trolley

The TBMs operating in Project CC-27 are: DOUBLE SHIELD TBM HK (Herrenknecht) was used on site for tunnel towards Shankar Vihar

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1. THI 1 TBM

2. THI 2 TBM

3. Okumura TBM

4. Herrenknecht TBM

5. Mitsubishi TBM

Selection of TBM depends on many factors of which the most important factor is the ground profile. These TBMs can also be broadly classified into Soil TBM, Mixed TBM and Rock TBM. A TBM typically consists of one or two shields (large metal cylinders) and trailing support mechanisms. At the front end of the shield is a rotating cutting wheel. Behind the cutting wheel is a chamber where, depending on the type of the TBM, the excavated soil is mixed with slurry. Systems for removal of the soil are also incorporated into the machine system. Behind the chamber there is a set of hydraulic jacks supported by the finished part of the tunnel which push the TBM forward.

The action here is much like an earthworm. The rear section of the TBM is braced against the tunnel

walls and used to push the TBM head forward. At maximum extension the

TUNNEL VASANT VIHAR TO SHANKAR VIHAR

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The systems are mainly planted for the works such as dirt removal, slurry pipelines if applicable, control

rooms, and rails for transport of the precast segments. The cutting wheel cut the rock face into chips or

excavate soil (known as muck). Depending on the type of TBM, the muck will fall onto a conveyor belt

system and be carried out of the tunnel, or be mixed with slurry and pumped back to the tunnel entrance.

Depending on rock strata and tunnel requirements, the tunnel may be cased, lined, or left unlined. This

may be done by bringing in precast concrete sections that are jacked into place as the TBM moves

forward, by assembling concrete forms, or in some hard rock strata, leaving the tunnel unlined and

relying on the surrounding rock to handle and distribute the load.

TBM(TUNNEL BORING MACHINE) ASSEMBLY ORIGINAL ABOVE AND ANIMATED SHOWN BELOW

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The segmental lining has been designed to withstand thegroundwater, soil pressure and permanent loads.

Design loads parameters include Earth Pressure, Groundwater pressure, Grouting Pressure, Jacking

forces, Short term & Long term handling force, Segment misalignment and Bolt & gasket forces. Initial

setups to be done before drive:

1. Ground Treatment

2. Installation of Cradle

3. TBM lifting & assembly

4. Installation of Reaction Frame

5. Installation of Temporary segments

6. Tunnel Eye breaking

Before starting the tunnelling activities, it is necessary to improve the soil characteristics at the head of

the launching shaft /retrieval

shaft and along the cross

passage. High Pressure Jet

grouting method to improve

the soil stabilization (350 to

400 bar pressure). Cradle is

fixed according to the tunnel

centre line before TBM

unloading. Reaction frames

are erected to guide to Initial

Push for TBM without any

Backup Gantry. Tunnel eye is

broken by hacking along the

Tunnel circumference

alignment.

COMPENSAION GROUTING