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50
th
IG
C
50th
INDIAN GEOTECHNICAL CONFERENCE
17th
– 19th
DECEMBER 2015, Pune, Maharashtra, India
Venue: College of Engineering (Estd. 1854), Pune, India
SHALLOW FOUNDATION ON DUMPED SOIL
R. R. Darange1, Milinda Mahajan
2, Ajitkumar Kumbhar
3, H. B. Dhonde
4, R. Acharya
5
ABSTRACT
Dumped soils, formed by man-made deposition of excavated earth material generally without any
engineering treatment are a common occurrence in industrial sector throughout India. Such soils are
seldom used to support buildings owing to their perceived unpredictable and erratic behavior.
Nonetheless, supporting minor and non-critical structures on sufficiently consolidated and relatively
strong dumped soils using shallow foundation may be a lucrative option, though very few cases are
available on this topic. Guidelines and recommendations specifically for dumped soil characterization,
testing protocol, and analysis are not available.
The paper presents a case study of an engine storage building constructed with pre-engineered steel and
supported on dumped soil. The column service loads were of light-to-medium magnitude in the range of
500 to 1200 kN. About 7 m thick dumped soil was placed at the proposed building location during
previous construction about 4 years back over a preexisting Black Cotton (BC) soil layer of
approximately 2 m thick, with hard weathered rock strata at the bottom. However, strong rock strata was
available at relatively lower depths in the rest of the footprint area. Thus, long-term differential settlement
of foundation and its effect on the superstructure was a major concern.
(Not to Scale)
Fig. A Case Study of Shallow Foundation on Dumped Soil
R. R. Darange, Milinda Mahajan, Ajitkumar Kumbhar, H. B. Dhonde, and R. Acharya
Options such as deep seated footing on hard strata, and deep foundation were evaluated but found to
be expensive and overly-conservative solution for the structure that is not critically important nor
heavily loaded. Moreover, advantage of the pre-consolidated BC layer having low swelling potential,
located close to or below the plausible depth of insignificant stress intensity (isobar), to carry part of
the load, was ignored in this option. Eventually, a practical and economical shallow footing with soil
improvement - by partial replacement of the dumped soil with appropriate cohesive non-swelling
compacted fill, was chosen.
Extensive soil investigation and laboratory tests were carried out to ascertain the extent and
engineering characteristics of each soil layer. Several bore holes were taken with standard penetration
tests conducted at suitable levels. Large diameter plate load tests were carried out on soil before and
after the soil improvement . Considering permissible soil strength and settlement limits, a safe shallow
foundation with soil improvement was provided to support the industrial storage structure. The
footing settlements were monitored by telltale markings on site. It has been 8 months post-
construction with 3 months of wet season, and no significant/recordable settlements were noted.
A parametric analysis of subsoil behavior considering different types of soil-layered systems is also
presented, and results of conventional analysis of shallow foundation are compared with software tool
such as SAFE and MIDAS FEA. The study indicated that the depth at which significant displacement
occurred (of about 25 mm), was approximately 1B and 0.5B in case of relatively strong non-cohesive
and cohesive soils, respectively (where B is the footing width). Settlement in soil strata was found to
be greatly affected by the depth of relatively soft BC soil layer below the footing level. The estimated
safe bearing capacity and subgrade modulus by software for the various soils compared well with the
presumptive values typical for such soils.
The study demonstrates practicality and feasibility of providing shallow foundations to support minor
loads on dumped soils. Opting for shallow foundation supported on adequately strong dumped soils
could save considerable cost, but may entail larger spending later due to settlement damages. The
decision to go for shallow or deep foundation depends on the importance and utility of the structure,
suitable soil characteristics, and on the ability and willingness of the client to take an informed and
calculated risk.
Keywords: Dumped soil, black cotton soil, shallow foundations, case study, bearing capacity,
settlement, parametric analysis
__________________
1Er. R. R. Darange, Graduate Student, Department of Civil Engg., VIIT, Pune, India, [email protected]
2Dr. Milinda Mahajan, Associate Prof., Department of Civil Engg., VIIT, Pune, India, [email protected]
3Er.Ajitkumar Kumbhar, Manager, Mahindra Vehicle Manuf. Ltd, Chakan, India, [email protected]
4Dr. H. B. Dhonde, Associate Prof., Department of Civil Engg., VIIT, Pune, India, [email protected]
5Er. R. Acharya, Graduate Student, Department of Civil Engineering, VIIT, Pune, [email protected]
50
th
IG
C
50th
INDIAN GEOTECHNICAL CONFERENCE
17th
– 19th
DECEMBER 2015, Pune, Maharashtra, India
Venue: College of Engineering (Estd. 1854), Pune, India
SHALLOW FOUNDATION ON DUMPED SOIL
R. R. Darange, Graduate Student, Department of Civil Engineering, VIIT, Pune, [email protected]
Milinda Mahajan, Associate Professor, Department of Civil Engineering, VIIT, Pune, [email protected]
Ajitkumar Kumbhar, Manager, Mahindra Vehicle Manufacturing Ltd, India, [email protected]
H. B. Dhonde, Associate Professor, Department of Civil Engineering, VIIT, Pune, [email protected]
R. Acharya, Graduate Student, Department of Civil Engineering, VIIT, Pune, [email protected]
ABSTRACT: Dumped soils behave erratically and therefore are seldom used to support buildings. Nonetheless,
supporting minor and non-critical structure on suitable dumped soil using shallow foundation may be a worthwhile
option. The paper presents a case study of an industrial steel building supported by a shallow foundation with soil
improvement, on dumped soil. Parametric study of engineering behavior of various classes of dumped soils formed
by a combination of different types of soil layers is also presented. Furthermore, comparison of the performance of
shallow foundation by conventional analysis and software tools is presented. The study demonstrates feasibility of
providing shallow foundation to support minor loads on dumped soils.
INTRODUCTION
Innovative engineering solutions to practical
problems usually extend beyond the standard codes
of practice. One such eminent problem faced by
today’s industrial sector is lack of space and
therefore to optimally utilize the area filled with
old or recently dumped soil, also known as non-
engineered filled-up soil or reclaimed infill or land-
fill. Dumped soil, as the name suggests – is a soil
that is usually excavated, locally transported and
dumped on adjoining site. The process of dumping
in general is uncontrolled and random and in many
cases the origin, history and ingredients of dumped
soil are unknown. Engineering behavior of dumped
soil is believed to be uncanny and erratic [1].
Generally, as per code practice shallow
foundations need to be placed below the zone of
dump or any loose fill. There is dearth of literature
and lack of regulatory guidelines on analysis and
design of shallow foundations on dumped soils in
India.
Dumped soil is a common occurrence at industrial
sites. Newer dumped soils usually will be weak in
strength and susceptible to excessive settlement
and shear yielding under nominal loads than
consolidated aged dumped soils. Most commonly,
a costly option of deep foundation is prescribed
even for a non-critical structure with light-to-
medium range of loads (i.e. warehouse or holding
area). Therefore, the prospect of a cost-effective
shallow foundation supporting a light-to-medium
weight steel structure on a dumped soil may be a
lucrative yet challenging option to an engineer. In
geotechnical context, it is a challenging task to
ascertain the properties, behavior and performance
of shallow foundation on dumped soil. Practical
solution to such problem, not necessarily confining
to the realm of code practice, and involving some
impending risks that are accepted by all
stakeholders, is required.
The best estimation of bearing capacity and
settlement of dumped soil under a load is possible,
if pressure-settlement characteristic of founding
soil are estimated for that size of footing. In case of
dumped soil, bearing capacity is usually governed
by settlement performance rather than shear
strength. Extensive geotechnical investigation may
be required to reliably establish the soil
characteristics needed for foundation analysis and
design. It may be appropriate to consider dumped
soil as layered soil and conventional theories
R. R. Darange, Milinda Mahajan, Ajitkumar Kumbhar, H. B. Dhonde, and R. Acharya
supported by software computations could be used
to predict the behaviour of dumped soil.
RESEARCH SIGNIFICANCE
In recent years, populations of cities are increasing
and cities are expanding. Due to lack of space it is
necessity to construct a light-to-medium loaded
structure on locally available and already existing
dumped soil. Commonly, fill of relatively cheap
materials such as waste or dumped soil are required
to raise the formation level of structure to support
lighter superimposed loads. Usually, a hard stratum
is available at greater depth below a dumped fill
for seating a deep foundation, thereby making the
option costly and time consuming.
The demand to support structure on cost effective
shallow foundation on dumped soils is ever
increasing. Practical and economically viable
solutions to support the structures on dumped soils
are available. However, suitable analysis and
design guidelines supported with real-life examples
are required to confidently implement such
solutions. An attempt is made here to provide a
general protocol for the prerequisite soil
investigation, soil testing, analysis and design of
shallow foundation on dumped soil by presenting a
case study, backed by parametric and software
analysis of the case study and various different
classified groups of dumped soils.
LITERATURE REVIEW
In case of any building founded on dumped soil,
the soil is the weakest link. Hence, reliable
identification and characterization of the dumped
soil is important to warrant a safe and serviceable
structure. The characterization of dumped soil can
be based on engineering and physical properties,
content of mineral composition and particle size
distribution [1]. These soil properties could then be
used to determine the soil behaviour pertaining to
settlement and strength. The qualitative and
quantitative identification of the weakest or
problematic materials (such as waste and debris)
in dumped soil is important. Waste type can be
determined by particle size distribution analysis,
physical and chemical tests on representative
dumped soil samples [1].
Previous studies have recommended a soil
mechanics based model for settlement
determination of dumped soil [2]. Ground
improvement techniques such as lime stabilization,
mechanical compaction, pre-loading, vibro-
floatation, stone-piling and soil-draining have been
found effective in reducing the settlement and
enhancing the strength characteristics of dumped
soil [3, 4, 5]. CASE STUDY
Construction of a 19,500 m2
– 10 m high Pre
Engineered steel Building (PEB) was carried out at
Mahindra Heavy Engines Pvt. Ltd. (MHEPL),
Chakan, Pune, MH-India, as depicted in Fig.1. The
building is to be used for engine manufacturing,
assembly, and engine and material storage, hence
without any provision of an over-head crane in
filled up area. The column service loads were of
light-to-medium magnitude, i.e. in the range of 500
to 1200 kN.
Fig.1 PEB Footprint with Dumped Soil at MHEPL
Dumped soil was deposited on a 3025 m2 area
during previous construction about 4 years back,
over a small stream consisting of a layer of Black
Cotton (BC) soil, with hard strata at the bottom; on
the south-eastern part of the proposed new
construction shown in Fig. 1. Hard rock strata was
available at relatively lower depths in the rest of
the footprint area. Thus, long-term differential
settlement of foundation and its effect on the
superstructure was a major concern. Options such
Dumped Soil
50
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INDIAN GEOTECHNICAL CONFERENCE
17th
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DECEMBER 2015, Pune, Maharashtra, India
Venue: College of Engineering (Estd. 1854), Pune, India
as shallow independent footing with soil
improvement, deep seated footing on hard strata,
and deep foundation were studied.
Ground Condition at Site
Fig. 2 Ground Conditions at MHEPL Project Site
The soil profile at site was obtained from two bore
holes and an examination pit as depicted in Fig. 2,
along with a photograph of the exposed soil profile
[6]. A 2 m thick BC soil layer is sandwiched
between the dumped soil at top and virgin
weathered hard rock with traces of gravel at
bottom. 47 PEB columns out of a total of 147 were
located over the dumped soil area. The dumped
soil was found to be a random mixture of majorly
gravel and some proportions of boulders (0.5 m
size), sand, clay, silt, concrete waste and other
debris. Standard Penetration Test (SPT) N values
for the dumped soil varied from 11 to refusal (most
likely false-refusal due to presence of large
boulders). The N values of dumped soil at 2 m
below GL i.e. proposed Bottom of Footing (BOF)
level, were significantly large (N = 26 to 33),
owing to the compaction of this soil by 4 years of
vehicular traffic. Plate Load Test (PLT, 600 mm
diameter plate) data on the dumped soil at BOF
level, indicated a settlement of only 5 mm for a
recommended bearing capacity of 1500 kN/m2.
Consolidation test data revealed the BC soil to be
in a pre-consolidated state, due to overburden of
dumped soil for several years [6]. Thus, in this case
compressibility and lower strengths of the soil
layers would either require major soil
improvement/replacement or provision of deep
foundation to support the structure.
Recommendation by Consultants
The client (MHEPL) sought solution options from
several consultants on this case, as presented
below;
Option-1: Deep Seated Foundation
It was perceived that constructing foundation on
soft cohesive BC soil could suffer excessive
settlement. Hence, one of the consultants proposed
a seemingly large R.C.C. isolated footing with
slender pedestal column stiffened with lateral tie
beams to be placed on the virgin hard strata at
about 12 m (4-stories) below Final Formation
Level (FFL), as shown in Fig. 3.
Fig 3 Deep Seated Foundation with Lateral Ties
Lateral Tie Beam Dumped Soil
Layer-1
Black Cotton Soil Layer-2
-3m BOF
SPT-N = 4
SPT-N = 26
SPT-N = 100
12.2m BOF
R. R. Darange, Milinda Mahajan, Ajitkumar Kumbhar, H. B. Dhonde, and R. Acharya
The main intention of this option was to provide an
absolutely positive bearing and full transfer of
superimposed loads on to the hard strata so as to
eliminate the potential differential settlement as
well as to offer a high-factor of safety with very
low associated risks. However, a general consensus
over this option was that it would be too costly and
overly-conservative solution for the structure that
is not critically important nor heavily loaded.
Moreover, advantage of the pre-consolidated BC
soil layer, located close to or below the plausible
depth of insignificant stress intensity (isobar), to
carry part of the load, was ignored in this option.
Option-2: Shallow Foundation with Soil Improvement
Based on the findings of an extensive geotechnical
investigation and soil testing, two of the other
consultants independently recommended a shallow
foundation with soil improvement (see Fig. 4)
instead of Option-1. The design basis for their
solution was that practically, all types of
construction can be founded on fills, provided the
structure is suitably designed to tolerate the
anticipated settlement, soil shear failure is avoided,
and the fill is properly placed and compacted [7].
Fig. 4 Shallow Foundation on Dumped Soil
The key idea of Option-2 was to support the
structure on compacted engineered fill over the
existing dumped soil, which was resting on a well
consolidated BC soil with low swelling potential.
This option required excavations of only 4 m
depth, partial replacement of the existing dumped
soil by well compacted Cohesive Non-Swelling
(CNS) soil, and short pedestal footing, thus saving
an estimated Rs. 1.15 Crs., compared to the cost of
Option-1. However, particular caution was
required to implement Option-2. Considering that
the footings on the boundary of the dumped soil
zone would be supported on relatively rigid hard
rock, and the foundations were to be supported at
different formation levels and on different soil
formations, possibility of excessive differential
settlement is high. It was therefore imperative to
design a stiff and stable foundation with suitable
provisions in the PEB superstructure to resist the
expected differential settlement, without causing
unacceptable damage to the superstructure,
cladding, and roofing elements.
Analysis and Methodology
Following protocol was adopted for implementing
the Option-2 solution,
1. Sub surface investigation of soil
2. Determination of the physical and engineering
properties of all soils in the subsoil
3. Bearing capacity and settlement estimates
4. Settlement evaluations by software
5. Structural design of square footing
6. Monitoring and present status
Subsurface Investigation
An extensive geotechnical investigation was
carried out to satisfactorily establish the nature and
various properties of the soil strata on this project.
Subsurface investigation was carried out in two
stages i.e. preliminary and detailed. Preliminary
investigation was restricted to determination of
depth, thickness, extent, composition of soil
stratum, water table levels, geological features,
history and information regarding soil strata by
digging trial pits and preliminary drill holes. A
total of three 100 mm diameter boreholes were
drilled to refusal across the area of dumped fill. A
large variation in thicknesses of the 3-layers of
soils was observed from the borehole data. Water
table level was recorded to be about 5.7 m below
GL. Field tests such as the large-diameter PLT and
SPT were carried out to estimate the bearing
50
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INDIAN GEOTECHNICAL CONFERENCE
17th
– 19th
DECEMBER 2015, Pune, Maharashtra, India
Venue: College of Engineering (Estd. 1854), Pune, India
capacity and settlement behavior of the soil, as
explained in the previous section.
Physical and Engineering Properties of Subsoil
Suitable laboratory and field tests on soil were
carried out to ascertain the physical and
engineering properties of soil layers at the site.
However, it is difficult to determine the qualitative
and quantitative nature of the debris contents in the
dumped soil, by any field or laboratory tests.
Representative soil samples were tested for general
classification of the soils. These properties of the
dumped soil (Layer-1) and BC soil (Layer-2) are
shown in Table 1 and 2. Based on these tests, the
BC soil (SPT-N value-range = 4 to 14) was
classified as Silty-Clay with High plasticity (MH-
CH; as WL>50%). The BC soil was designated as
relatively weak soil of poor bearing strength, as
also affirmed by the low value of SPT-N. It had a
medium degree of expansion and marginal degree
of severity with regards to swelling pressure [8].
Table 1 Properties of BC soil (MH) at MHEPL
Physical
Property
Sy
mb
ol
Un
it SPT-UDS SPT-DS
Sample Sample
1 2 3 4
Moisture
Content w % 37.51 43.81 32.13 36.13
Dry Density γdry g/cc 1.33 1.3 - -
Bulk Density γbulk g/cc 1.83 1.87 - -
Liquid Limit WL % 82 63 64 86
Plastic Limit PL % 38 42 29 36
Plasticity
Index IP % 44 21 35 50
Free Swell
Index FSI % 58 75 46 82
Compression
Index Cc - 0.22 0.217 - -
UDS – Undisturbed Sample, DS – Disturbed Sample
Table 2 Properties of dumped soil (G) at MHEPL
Property Unit Value
Grain
Size
Analysis
Gravel % 78
Sand % 12
Silt % 10
Specific Gravity - 2.8
Moisture Content % 8.7
The dumped soil was found to be non-cohesive
Gravel (G), with about 80% of gravel content and
some large boulders.
Bearing Capacity and Settlement
The estimated bearing capacities and settlements
for the layered soil system by analytical and
experimental methods is presented in Table 3.
Table 3 Estimated engineering performance of soil
Total estimated settlements are within tolerable
limits and bearing capacity of soil strata based on
field-tests and analytical methods are also
satisfactory for the superimposed loads. Footing is
safe against the estimated swelling pressure from
BC soil. Hence, from the estimated results it is
clear that the shallow foundation placed on the
dumped soil and underlain by BC soil can be
deemed safe and serviceable.
Settlement Evaluation by Software
Engg.
Property Calculated Value / Criteria Remarks
Settlement
of BC Soil
Total settlement = 23 mm
Differential settlement = 17 mm
Designed
superstructure can sustain this
deformation
Uplift/
Swelling
of BC Soil
Total vertical stress on top of BC
soil = 140 kN/m2 (min.)
and 170 kN/m2 (max.)
Maximum swelling pressure of BC
soil [6] = 30 kN/m2
Safe against soil uplift / swelling
pressure
Safe
Bearing
Capacity
Field Method-
BC soil = 200 kN/m2 (by SPT)
Compacted CNS fill = 150 kN/m2
(by PLT)
Analytical Method-
BC soil:
Terzaghi’s equation = 206 kN/m2
Dumped soil (G) and CNS Fill:
Terzaghi’s and Peck’s equation =
132.6 kN/m2 @ 25 mm settlement
Result by field-test and
analytical
method are nearly equal.
Footing can
safely support a
superimposed service load of
2000 kN, i.e.
twice the actual load.
Footing is Safe
in Bearing
Capacity.
Consolidat-
ion Time-
BC Soil
Time required for consolidation of
BC soil, Tfield = 2.3 years
Long term
settlement
monitoring reqd.
R. R. Darange, Milinda Mahajan, Ajitkumar Kumbhar, H. B. Dhonde, and R. Acharya
Elastic soil settlement under the shallow
foundation was determined using software tool
(SAFE), considering soil properties of various
layers, before and after ground improvement. The
results of elastic and time-dependent consolidation
soil settlements obtained from the software
analysis and analytical calculation, respectively are
shows in Table 4. The benefits of ground
improvement i.e. partially replaced dumped soil
with compacted CNS soil, on the settlement
performance are evident, with over 50% reduction
in total settlement.
Table 4 Estimated settlements for footing
Ground
Condition
Modulus of
Subgrade
(kN/m3)
Settlement (mm)
Elastic Consolidation# Total
Before
Ground
Improvement
G-Layer 1
=15000
BC-Layer 2
=20000
10 23 33
After Ground
Improvement
Layer 1 & 2
=31500 3 12 15
# - Calculated by conventional analysis
Structural Design of Square Footing
The isolated footing was designed for a total
service gravity load of 1000 kN, considering the
estimated safe bearing capacity based on settlement
criteria, and choosing optimum footing width such
that the resulting extent and magnitudes of isobars
would be satisfactory. The structural design for
strength was verified for the ultimate factored
loads. Thickness of footing was governed by the
maximum punching shear stress. Table 5, depicts
the design details of the shallow footing.
Table 5 Details of the shallow footing
Property Value
Grade of Steel/Concrete Fe415/M30
Footing Size 4m x 4m
Column Size 600 mm x 600 mm
Footing thickness 430 mm
Reinforcement 4580mm2 E.W.-T&B; ɸ20mm
Monitoring and Present Status
The footing settlements were monitored by telltale
markings on site. It has been 8 months post-
construction with 3 months of wet season, and no
significant/recordable settlements were noted.
Also, no signs of differential settlements were
observed in the structure.
PARAMETRIC ANALYSIS
Soil Properties and Soil Models
The objective of carrying out the parametric
analysis of lightly loaded shallow foundation on
dumped soil with different possible combinations
of layers of soils having typical range of properties
was to evaluate the performance of the substructure
and soil strata under different soil conditions. This
study would provide the readers a basic guideline
with examples of range of situations of shallow
foundation on dumped soil.
Fig. 5 Parametric Analysis for Soil Model-11
(MHEPL Case Study)
Parametric study was carried out using 2D MIDAS
FEA software with different soil models, as shown
in Fig. 5. 35 different soil models were analyzed
considering combinations of three soil layers (i.e.
Gravel, Sand and BC soil) having different strength
class (i.e. soft/loose, medium, and stiff/dense). Soil
0
6.0
8.5
10.5
1000 kn
Pressure Distribution
L.Gravel
BCS
Hard Rock
kN Soil Model -11
50
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INDIAN GEOTECHNICAL CONFERENCE
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DECEMBER 2015, Pune, Maharashtra, India
Venue: College of Engineering (Estd. 1854), Pune, India
models were analyzed with rigid - 4m x 4m
footing, 1m below GL under 1000 kN column
service load. Safe bearing pressure, subgrade
modulus and vertical settlement (Fig. 5) were
determined for the soil models. Table 6 indicates
the summary of analytical results for various soil
models.
Table 6 Result summary of parametric analysis
The total settlements computed by the software and
conventional analytical methods for majority of the
models were close. The depth at which significant
displacement occurred (of about 25 mm), was
found to be approximately 1B and 0.5B in case of
relatively strong non-cohesive and cohesive soils,
respectively (where B is the footing width). Settlement in soil strata was found to be greatly
affected by the depth of relatively soft BC soil
layer below the footing level. As the depth to BC
soil layer increased the settlement decreased.
The estimated safe bearing capacity and subgrade
modulus by software for the various gravel and BC
soils compared well with the presumptive values
typical for such soils. In case of Soil Model-11
(MHEPL case study), it can be noted that the
calculated and software (by SAFE and MIDAS)
settlement estimates were close and within the
permissible limits.
COST COMPARISON
Material cost estimates of shallow and deep
foundation designs were done considering three
representative soil model cases having low,
medium and high bearing capacity and subgrade
modulus, as shown in Table 7. In case of low
strength dumped soils, shallow foundation is
costlier than deep foundation. Therefore, it is
rational to provide deep foundation in case of very
soft soils. However, in case of medium to high
strength dumped soils, it is viable to provide
shallow foundation.
Table 7 Material cost comparison for foundations Item Case 1 Case 2 Case 3
Bearing Capacity Very Low Medium High
Subgrade Modulus, kN/m3 ≤ 12000 12000-30000 ≥30000
Shallow Foundation , Rs. 1,51,200 10,640 8220
Deep Seated Footing, Rs. 79,298
Opting for shallow foundation supported on
adequately strong dumped soils could save
considerable cost. Nonetheless, shallow
foundations in such cases may be prone to
differential settlement and damages there of that
would entail larger spending later. On the other
hand, deep foundations may prove to be
economical in the long run, especially in case of
supporting important structures.
CONCLUSIONS
The paper demonstrates the feasibility of providing
shallow foundations to support light-to-medium
loaded structure on suitable dumped soils. The
availability of acceptable depth to reasonably
R. R. Darange, Milinda Mahajan, Ajitkumar Kumbhar, H. B. Dhonde, and R. Acharya
strong strata plays an important role in deciding
between shallow or deep foundation to support a
structure on dumped soil. For a shallow foundation
to be safely supported on dumped soil, the extent
and magnitude of resulting isobars up to the
significant depth of influence is an important
consideration.
Hence, in such situations appropriate geotechnical
investigation is vital for establishing satisfactory
and reliable design parameters. Consequently, it is
important to provide a stable foundation on
dumped soil and suitable superstructure to safely
resist the anticipated differential settlements.
Resting a footing on soft or loose soil directly or
indirectly, may be risky unless proper measures are
taken to ensure its safety against bearing and
settlement failures. The decision to choose between
shallow or deep foundation depends on the
importance and utility of the structure, suitable soil
characteristics, and on the willingness of the client
to take an informed and calculated risk.
REFERENCE 1.
1. Pauzi, N.I.M., Omer, H., Huat, B.B.K. and
Misran, H. (2014), Characterization of waste
soil of open dumping area, Electronic Journal
of Geotechnical Engineering, Vol. 19, Bundle-
F,1265-1279, http://www.ejge.com.
2. Pauzi, N.I.M., Omer, H., Huat, B.B.K. and
Misran, H. (2010), Settlement model for waste
soil for dumping area in Malaysia, Electronic
Journal of Geotechnical Engineering, Vol. 15,
Bundle-R, 1917-1929, http://www.ejge.com.
3. Arifuzzaman Md. and Hasan, A. (2013),
Evaluation of foundation difficulties over soft
organic soil, Jordan Journal of Civil
Engineering, Vol. 7, No. 4, 440-449.
4. Ramasubbarao G.V. (2011), Foundation
practices and rehabilitation of structure on
expansive soil, NBM&CW Magazine, Issue:
June, India.
5. Murthy, S.B.R. (2012), Case studies in
geotechnical engineering construction:
Construction of buildings on 6m thick filled
up soil, 34th
IGS Annual Lecture, Indian
Geotechnical Conference, 13th
Dec, New
Delhi, India.
6. Soiltech (I) Pvt. Ltd., Geotechnical Consultant
(2014), Geotechnical Report for MHEPL,
Chakan-India, Private Report.
7. Guyer, J.P. (2013), An introduction to
foundations on fill and backfilling, 1st
Ed.,
CreateSpace Publishers, Delaware USA.
8. IS 1498-1970 (Reaff. 2007), Classification
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