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GEOTECHNICAL INVESTIGATION
REPORT
FINAL REPORT ON SOIL INVESTIGATION WORK FOR PROPOSED 2 x 25 MVA 66/11kV G-1
SUB-STATION AT DWARKA, NEW DELHI.
RAO ENGINEERING ENTERPRISES (GEOTECHNICAL CONSULTANTS & LAND SURVEYOURS)
91/D3, STREET NO. 1, EAST MOTI BHAG, OLD ROHTAK ROAD, DELHI-110007 PHONE: 011-23698806, 011-23691434, MOB: 09310502435, 09811108174
E-MAIL: [email protected], [email protected]
.
June 17th, 2017 Project No. 17079 M/s. BSES Rajdhani Power Limited 1st Floor, C-Block, BSCS Bhawan, Nehru Place, Delhi - 110019 Sub: Final Report on Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-
Station at Dwarka, New Delhi. We have carried out the soil investigation work in accordance with your Work Order No. SER/DSC/23558177 dated June 2nd, 2017. We thank you for your business, and hope that you are satisfied with our services rendered. This Final Report presents our findings based on the soil investigations conducted by us at the project site. This report presents the field and laboratory test data, along with our engineering recommendations, which shall help you in deciding the optimum foundation arrangement for use on site. We have prepared this report based on our findings on site, as well as our experience gained in our previous projects completed over the past 10 years. We appreciate the opportunity to perform this investigation for you and have pleasure in submitting this report. Please contact us when we can be of further service to you. Yours faithfully, RAO ENGINEERING ENTERPRISES
(G.R.RAO)
Project No. 17079 i
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
TABLE OF CONTENTS Page No
1.0 INTRODUCTION 1 1.1 Project Description 1 1.2 Aim of Soil Investigation 1 1.3 Scope of Work 1
2.0 FIELD INVESTIGATIONS 1 2.1 Soil Borings 1 2.2 Groundwater 2 2.3 Electrical Resistivity Tests 2
3.0 LABORATORY TESTS 3
4.0 GENERAL SITE CONDITIONS 3 4.1 Site Stratigraphy 3 4.2 Groundwater 4
5.0 FIELD TEST RESULTS 4 5.1 Electrical Resistivity Test Result 4
6.0 FOUNDATION ANALYSIS 4 6.1 General 4 6.2 Liquefaction Susceptibility Assessment 5 6.3 Foundation Type and Depth 5 6.4 Allowable Bearing Pressure 5 6.5 Sample Calculations 6
7.0 RECOMMENDATIONS 7
8.0 CHEMICAL RESULTS 7
9.0 VARIABILITY IN SUBSURFACE CONDITIONS 8
ILLUSTRATIONS
Caption Figure Layout Plan 1 Soil Profiles 2 to 9 Summary of Borehole Profiles 10 & 11 Standard Cone Penetration Test Results 12 to 15 Electrical Resistivity Test Results 16 & 17 Grain Size Test Results 18 to 25 Chemical Test Results 26
-------------------------------------------------------
Project No. 17079 Page 1 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
1.0 INTRODUCTION
1.1 Project Description
This soil investigation work, whose results are being presented herewith, has been
carried out for Proposed 2 x 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
The geotechnical investigation work on site has been carried out in accordance with Drawing No. BRPL-GIDW-DEE-B-0002 entitled “LAYOUT OF 2x25 MVA 66/11kV G-1 DWARKA GRID” dated April 7th, 2017 issued to us. A layout plan illustrating the test locations of our field investigation is presented on Fig 1.
1.2 Aim of Soil Investigation
Soil investigation has been conducted at the site in order to evaluate the parameters required for design of foundations. These parameters are:
a) Type of foundation on which the proposed super structure will be supported.
b) Depth of foundation, and
c) Allowable bearing pressure at the founding level.
To evaluate these parameters, following engineering properties of the Sub-Soil have
been studied: Sub-soil penetration resistance characteristics which have been determined insitu.
Properties like particle size distribution, atterberg limits, bulk density, moisture content, and shear strength parameters; which have been determined in the laboratory by conducting testing of both disturbed as well as undisturbed samples.
1.3 Scope of Work
The stipulated scope of work comprised of the following:
1. Mobilization of equipment and personnel to the site and back.
2. Sinking eight (8) boreholes to 10.0 m depth or refusal whichever is encountered earlier, observing ground water table levels, conducting required field and laboratory tests and their analysis.
3. conducting one (1) electrical resistivity test (ERT’s) to provide data for the
grounding systems;
4. Preparation and submission of technical report in triplicate.
2.0 FIELD INVESTIGATIONS
2.1 Soil Borings The boreholes were progressed using mechanized shell and auger drilling rig to the
specified depth. The diameter of the borehole was 150 mm. Where caving of the borehole
Project No. 17079 Page 2 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
occurred, casing was used to keep the borehole stable. The work was in general accordance with IS: 1892-1979.
Standard Penetration Tests (SPT) were conducted in the boreholes at 1.5 m depth
interval up to 15 m depth. The tests were conducted by connecting a split spoon sampler to ‘A’ rods and driving it by 45 cm using a 63.5 kg hammer falling freely from a height of 75 cm. The tests were conducted in accordance with IS: 2131-1981.
The number of blows for each 15 cm of penetration of the split spoon sampler was
recorded. The blows required to penetrate the initial 15 cm of the split spoon for seating the sampler is ignored due to the possible presence of loose materials or cuttings from the drilling operation. The cumulative number of blows required to penetrate the balance 30 cm of the 45 cm sampling interval is termed the SPT value or the ‘N’ value.
Where the split spoon sampler did not penetrate the initial 15 cm seating in a total of
100 blows, it is indicated “Ref" for an indicated amount of penetration. The ‘N’ values are presented on the soil profile for each borehole.
Disturbed samples were collected from the split spoon after conducting SPT. The
samples were preserved in transparent polythene bags. Undisturbed soil samples were collected by attaching 75 mm diameter thin walled ‘Shelby’ tubes and driving the sampler by light-hammering using a 63.5 kg hammer in accordance with IS: 2132-1986. The tubes were sealed with wax at both ends. All samples were transported to our laboratory for further examination and testing.
2.2 Groundwater
Groundwater level was measured in the boreholes after drilling and sampling was completed. The measured water levels are recorded on the individual soil profiles.
2.3 Electrical Resistivity Tests
Electrical resistivity of the substratum (soil) at the site was determined at specified
locations. The electrical resistivity test is used for shallow subsurface exploration by means of electrical measures made at the ground surface. Resistivity measurements are made by driving four electrodes about 10 to 15 cm in to the ground at pre-selected electrode spacing. We used the Wenner electrode configuration for this study.
The schematic arrangement of electrodes is shown below:
NOTE: I1 AND I2 ARE CURRENT ELECTRODES
P1 AND P2 ARE POTENTIAL ELECTRODES
Project No. 17079 Page 3 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
The four electrodes were spaced at equal distance along a line. The test procedure is
in accordance with IS: 3043:1987 RA 2006. Measurements are made by causing a current, ‘I’, to pass through the earth and
distribute within a relatively large hemispherical earth mass. The portion of the current that flows along the surface produces a voltage drop, ‘V’. The resistance ‘R’, ratio of voltage drop ‘V’ to current ‘I’ is directly measured by Digital Earth Resistance Tester. The resistivity is determined from the following equation:
ρ = 2 π a R
where:
ρ = apparent resistivity, ohm-m a = spacing between the electrodes, meter R = resistance, ohms
Results are presented as semi-logarithmic plot of apparent resistivity versus electrode
spacing, as well as in the form of polar curves, as specified by IS: 3043:1987 RA 2006. 3.0 LABORATORY TESTS
Laboratory tests have been conducted on various selected soil samples in the
laboratory:
Laboratory Test IS Code Referred Bulk Density By calculations Natural moisture content IS : 2720 (Part-2)-1973, RA-2010 Specific Gravity IS : 2720 (Part-3)-1980, RA-2007 Grain size analysis IS : 2720 (Part-4)-1985, RA-2010 Liquid Limit and Plastic Limit IS : 2720 (Part-5)-1985, RA-2010 Unconfined compression test IS : 2720 (Part-10)-1991, RA-2010 Unconsolidated Undrained triaxial shear test IS : 2720 (Part-11)-1993, RA-2007
pH value IS : 2720 (Part 26)-1987, RA-2007 Sulphates IS : 2720 (Part-27)-1977, RA-2010 Chemical Analysis
of soil Chlorides IS : 3025 (Part-32)-1988, RA-2009
4.0 GENERAL SITE CONDITIONS
4.1 Site Stratigraphy A heterogeneous fill of sandy silt with brick bats is met to about 1.5 m depth. Below
this, sandy silt / silty sand is encountered to the final explored depth of 10.45 m. The field SPT N-values generally range form 5 to 9 to about 2.0 m depth. Below this,
field SPT N-values generally range from 7 to 19 to about 4.5 m depth and 15 to 32 to about 7.5 m depth. Below this, SPT N-values range from 26 to 53 to about 9.0 m depth and range from 51 to 90 m to the final explored depth of 10.45 m.
Project No. 17079 Page 4 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
All test results are presented on the individual soil profiles on Fig. 2 to 9. A summary of
the borehole profiles is illustrated on Fig 10 & 11. Plots of field and corrected SPT values versus depth are presented on Fig. 12 to 15.
4.2 Groundwater
Based on our measurements in the completed boreholes, groundwater was not met to
the final explored depth of 10.45 m during the period of our field investigations (June, 2017). Fluctuations may occur in the measured ground levels due to seasonal variations in rainfall, surface evaporation rates.
5.0 FIELD TEST RESULTS
5.1 Electrical Resistivity Test Result One (1) electrical resistivity test was conducted at the project site as per IS: 3043-1987.
The test was conducted using the Wenner configuration. The apparent resistivity value obtained has been analyzed to generate the polar curve. The polar curve is used to compute the mean resistivity.
Mean resistivity value at the electrical resistivity test (ERT) location is summarized in
the table below: Test
Designation Mean Resistivity,
ohm-m Corrosion potential* Presentation of Results
ERT-1 26.1 Moderately Corrosive Fig. 8 & 9 * As per Clause 8.6.1 of Amendment No. 2 to IS: 3043-1987, dated January 2010. The above value may be used for design of the electrical grounding system. The data
may also be used to assess the corrosion potential for buried utility lines as per the guideline given in IS 3043-1987.
6.0 FOUNDATION ANALYSIS
6.1 General For designing the foundation system, the following parameters are required:
a) Suitable type of foundation on which the proposed super-structure can be supported.
b) Depth of these foundations, and
c) Allowable bearing pressure at the founding level corresponding to various footing
sizes. A suitable foundation for any structure should have an adequate factor of safety against
exceeding the bearing capacity of the supporting soils. Also the vertical movements due to compression of the soils should be within tolerable limits for the structure. We consider that foundation designed in accordance with the recommendations given herein will satisfy these criteria.
Project No. 17079 Page 5 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
6.2 Liquefaction Susceptibility Assessment
Liquefaction is defined as the transformation of a granular material from a solid to a
liquefied state as a consequence of increased pore-water pressure and reduced effective stress (Marcuson, 1978)(1). Increased pore pressure may be induced by the tendency of granular materials to compact when subjected to cyclic shear deformation, such as in the event of an earthquake.
As per IS: 1893-2002, liquefaction is likely to occur in loose fine sand below water
table. Since groundwater was not met to the final explored depth of 10.45 m during the period of our field investigation (June, 2017).
On the basis of our preliminary assessment on limited data, we are of the opinion that
liquefaction is not likely to occur at the project site in the event of an earthquake. According to Fig.1 of IS: 1893 (Part-1)-2002 showing seismic zones, the project site
falls under Zone-IV. The design for seismic forces should be done considering the project site in Zone-IV.
6.3 Foundation Type and Depth
Type of foundation to be adopted for a particular structure depends upon the loading
intensity at the foundation level and the configuration of loading points. Reviewing the stratigraphy of the site on the basis of limited borehole data, SPT values
& laboratory test results, we are opinion that open foundation are feasible foundation scheme to support the structural load. Our recommendations of net allowable bearing pressures at minimum 2.0 m for open foundation are presented in the section of 7.0.
Interconnecting beams should be provided either at plinth level or at foundation level in
order to restrict differential settlements and to provide rigidity to the structure during earthquakes.
6.4 Allowable Bearing Pressure
Following criterion have been considered for evaluating the bearing capacity values:
(a) Settlement criteria
(b) Shear failure criterion
Shear failure condition as per I.S. 6403 has been considered for allowable bearing pressure computation. Allowable settlement value of 50 mm has been considered for deducing shear strength value.
(1) Marcuson, W.F. (III) (1978), “Definition of terms related to liquefaction”, J. Geotech Engg. Div,, SCE, 104(9),
1197-1200.
Project No. 17079 Page 6 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
6.5 Sample Calculations
Type of foundation Open foundation Depth of foundation 2.0 m. below EGL Width of foundation 3.0 m
I. SETTLEMENT CRITERIA (AS PER IS-8009, PART-1,1976, FIG.9, PAGE-17)
Weighted Average minimum Corrected ‘N’ value 11.0 Settlement undergone by footing per unit pressure 29.8 mm Settlement undergone by footing per Unit pressure considering water table Correction factor taken as 0.6 for Worst condition
47.7 mm
Allowable bearing pressure Corresponding to 50 mm allowable Settlement. 10.0 T/m²
II. SHEAR FAILURE CRITERION
The bearing capacity equation used is as follows:
qnet safe = 1 [cNcζc dc+ q(Nq-1) ζqdq+ 0.5 Bϒ Nγζγ dϒ Rw]
F
Where:
qnet safe = safe net bearing capacity of soil based on the shear failure criterion. q = overburden pressure Rw = water table correction factor
F = Factor of safety, taken as equal to 2.5 in accordance with IS: 1904-1986. ζc,ζq,ζγ = Shape factors. For Strip footings, ζc = ζq = ζγ = 1
For Square footing, ζc = 1.3, ζq = 1.2, ζγ = 0.6 dc ,dq, dγ = Depth factors For φ ≤ 10, dc = 1 + 0.2 tan (45 + φ / 2) D / B, dq = dγ = 1 For φ > 10, dq = dγ = 1 + 0.1 tan (45 + φ / 2) D / B Cohesion , c = 6.0 T/m² Angle of shearing resistance, ø = 6 degrees Bearing Capacity factors:
General Shear Failure : Nc = 6.81 Nq = 1.72 Nγ = 0.57
Local Shear Failure : Nc' = 6.19 Nq
' = 1.43 Nγ' = 0.34
Project No. 17079 Page 7 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
Overburden density , γ = 1.65 gms./cc
Net Safe Bearing Capacity , Q = 18.8 T/m² (considering average of Local & general shear criteria )
7.0 RECOMMENDATIONS
The following table presents our recommended values of net allowable bearing pressures for open foundations bearing at 2.0-2.5 m depth.
Recommended Net Allowable Bearing Pressure, T/m² Foundation Depth
below existing ground level, m Total Settlement =
40 mm Total Settlement =
50 mm
2.0 8.0 10.0
2.5 8.8 11.0
The above values include a safety factor of 2.5. Total settlement of foundation designed
for the above net bearing pressure is expected to be about 50 mm. Net bearing pressure for foundations at intermediate depths may be interpolated linearly
between the values given above. Fill placed above EGL should be treated as surcharge load. Foundation should be seated 0.5 m into natural soil.
In order to restrict the influence of adjacent footings on each other, the lateral edge-to-
edge spacing between the foundations should at least be equal to “0.8B” where ”B” is the width of the larger footing.
8.0 CHEMICAL RESULTS Results of chemical test on selected soil samples are presented on Fig No. 26. The results indicate that the soils contain 0.07-0.12 percent sulphates and 0.01-0.03
percent chlorides. The pH value of soil is 7.1-7.8. IS: 456-2000 recommends that precautions should be taken against chemical
degradation of concrete if
sulphates content of the soils exceeds 0.2 percent, or groundwater contains more than 300 mg /litre of sulphates (SO3).
Comparing the test results with these specified limits, the sulphate content of the
groundwater is higher than the specified limit. Groundwater was not encountered during our field investigation (June, 2017) and is not likely to influence foundation concrete. Therefore, strata at the site may be treated in Class-1 category as described on IS: 456-2000.
In our opinion, the soils at site are not aggressive to foundation concrete. We
recommend the following as a good practice to limit the potential for chemical attack:
Project No. 17079 Page 8 of 8
RAO ENGINEERING ENTERPRISES - - - GEOTECHNICAL REPORT
(1) The cement content in foundations concrete should be at least 280 kg/m3. (2) Water cement ratio in foundation concrete should generally not exceed 0.55. (3) A clear concrete cover over the reinforcement steel of at least 50 mm should be
provided for all foundations. (4) Foundation concrete should be densified adequately using a vibrator so as to form a
dense impervious mass.
9.0 VARIABILITY IN SUBSURFACE CONDITIONS
Subsurface conditions encountered during construction may vary somewhat from the conditions encountered during the site investigation. In case significant variations are encountered during construction, we request to be notified so that our engineers may review the recommendations in this report in light of these variations.
1
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Plan of Field Investigations
BH-1
BH-8
BH-7
ERT-1
BH-2
BH-3
BH-4
BH-5 BH-6
L E G E N D
Borehole (BH)
SYMBOL TYPE OF TEST
Electrical Resisitivity Test (ERT)
10-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 6 24 64 6
1.50 1.95 SPT-1 8 25.2 18.9 6.3
2.25 2.55 UDS-1 2.66 1.71 1.54 11.2 UUT 0.55 9
3.00 3.45 SPT-2 9 4.50 24.9 18.2 6.7
4.50 4.95 SPT-3 12 0 56 44 0 N P -
5.25 5.55 DS-2
6.00 6.45 SPT-4 39 N P -
7.50 7.95 SPT-5 26 2.63
8.25 8.55 DS-3 N P -
9.00 9.45 SPT-6 45
10.00 10.45 SPT-7 90 10.45 0 78 22 0 N P - 2.67
2
Client:10-Jun-17
1707910.45 Project No.M/s. BSES Rajdhani Power Limited
Date of Start: Date of Completion:
Atterberg Limits
Spe
cific
Gra
vity
SOIL PROFILE (BH-1)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No.
Termination Depth (m):
SOIL DESCRIPTION
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
Brown silty sand (SM)
Density and Moisture
Brown sandy silt of low plasticity (ML-CL)
Shear TestsGrain Size Analysis
Dep
th o
f Stra
ta, (
m)
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
11-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 1.50
1.50 1.95 SPT-1 5 25.6 19.7 5.9
2.25 2.55 UDS-1 3 22 68 7 2.66 1.65 1.52 8.4 UUT 0.45 7
3.00 3.45 SPT-2 7 4.50 23.9 18.2 5.7
4.50 4.95 SPT-3 13 N P -
5.25 5.55 DS-2 6.00 0 36 61 3 N p - 2.65
6.00 6.45 SPT-4 16 26.8 20.7 6.1
7.50 7.95 SPT-5 44
8.25 8.55 UDS-2 25.5 18.5 7.0 2.67 1.90 1.68 12.8 UCS 1.25 -
9.00 9.45 SPT-6 56
10.00 10.45 SPT-7 85 10.45 6 15 72 7 27.3 20.5 6.8
Brown sandy silt of low plasticity (ML-CL)
Fill: Silty sand
Grey sandy silt of low plasticity (ML-CL)
Grey sandy silt of non plasticity (ML)
Grain Size Analysis Atterberg Limits
Spe
cific
Gra
vity
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Date of Start: Date of Completion: 11-Jun-17Density and
Moisture
Termination Depth (m): 10.45 Project No.
M/s. BSES Rajdhani Power Limited
Shear Tests
17079
SOIL PROFILE (BH-2)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 3
Client:
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
11-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 1.50
1.50 1.95 SPT-1 9 0 18 74 8
2.25 2.55 UDS-1 27.2 20.8 6.4 2.66 1.70 1.57 8.1 UUT 0.65 6
3.00 3.45 SPT-2 12
4.50 4.95 SPT-3 20 24.8 18.6 6.2
5.25 5.55 UDS-2 0 24 69 7 2.65 1.86 1.66 12.3 UCS 0.85 -
6.00 6.45 SPT-4 28 7.50 26.8 20.1 6.7
7.50 7.95 SPT-5 50
8.25 8.55 UDS-3 29.2 21.1 8.1 2.68 1.89 1.68 12.4 UCS 1.10 -
9.00 9.45 SPT-6 62
10.00 10.45 SPT-7 87 10.45 5 15 71 9 25.5 19.1 6.4
Grey sandy silt of low plasticity (ML-CL)
Brown sandy silt of low plasticity (CL)
Grain Size Analysis Atterberg Limits
Fill: Silty sand
Spe
cific
Gra
vity
Density and Moisture
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
Date of Start: Date of Completion: 11-Jun-17
Shear Tests
Termination Depth (m): 10.45 Project No. 17079
SOIL PROFILE (BH-3)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 4
Client: M/s. BSES Rajdhani Power Limited
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
11-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1
1.50 1.95 SPT-1 8 25.6 18.9 6.7
2.25 2.55 UDS-1 2.66 1.71 1.54 11.2 UUT 0.50 8
3.00 3.45 SPT-2 9 0 22 71 7
4.50 4.95 SPT-3 12 5.00 26.1 19.5 6.6
5.25 5.55 UDS-2 3 36 58 3 N P - 2.64 1.82 1.66 9.6 UCS 0.75 -
6.00 6.45 SPT-4 39
7.50 7.95 SPT-5 26 N P -
8.25 8.55 DS-2 9.00 0 43 57 0 N P -
9.00 9.45 SPT-6 45 24.5 18.6 5.9 2.65
10.00 10.45 SPT-7 90 10.45 6 28 61 5
Brown sandy silt of non plasticity (ML)
Brown sandy silt of low plasticity (ML-CL)
Grain Size Analysis Atterberg Limits
Grey sandy silt of low plasticity (ML-CL)
Spe
cific
Gra
vity
Density and Moisture
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
Date of Start: Date of Completion: 11-Jun-17
Shear Tests
Termination Depth (m): 10.45 Project No. 17079
SOIL PROFILE (BH-4)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 5
Client: M/s. BSES Rajdhani Power Limited
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
12-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 24.5 18.4 6.1
1.50 1.95 SPT-1 9 0 33 62 5 2.66
2.25 2.55 UDS-1 1.71 1.55 10.2 UUT 0.55 9
3.00 3.45 SPT-2 14 4.50 25.1 18.6 6.5
4.50 4.95 SPT-3 22 0 61 39 0 N P -
5.25 5.55 DS-2
6.00 6.45 SPT-4 54 N P -
7.50 7.95 SPT-5 47 0 63 37 0 2.63
8.25 8.55 DS-3 N P -
9.00 9.45 SPT-6 63
10.00 10.45 SPT-7 87 10.45 N P - 2.68
Grain Size Analysis Atterberg Limits
Spe
cific
Gra
vity
Density and Moisture Shear Tests
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
Project No. 17079 Date of Start: Date of Completion: 12-Jun-17Client: M/s. BSES Rajdhani Power Limited Termination Depth
(m): 10.45
Brown sandy silt of low plasticity (ML-CL)
Brown silty sand (SM)
SOIL PROFILE (BH-5)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 6
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
12-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 1.50
1.50 1.95 SPT-1 12 26.8 19.6 7.2
2.25 2.55 UDS-1 0 19 73 8 2.66 1.71 1.55 10.2 UUT 0.60 7
3.00 3.45 SPT-2 14 4.50 24.5 18.9 5.6
4.50 4.95 SPT-3 17 0 63 37 0 N P - 2.63
5.25 5.55 DS-2 6.00 N P -
6.00 6.45 SPT-4 26 27.2 20.5 6.7
7.50 7.95 SPT-5 28 2.67
8.25 8.55 UDS-2 26.1 18.5 7.6 1.87 1.66 12.8 UCS 1.09 -
9.00 9.45 SPT-6 44
10.00 10.45 SPT-7 66 10.45 4 26 64 6 25.2 19.3 5.9
Grain Size Analysis Atterberg Limits
Spe
cific
Gra
vity
Density and Moisture Shear Tests
Date of Start: Date of Completion: 12-Jun-17
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Termination Depth (m): 10.45 Project No. 17079
SOIL PROFILE (BH-6)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 7
Client: M/s. BSES Rajdhani Power Limited
Fill: Silty sand
Brown sandy silt of low plasticity (ML-CL)
Brown silty sand (SM)
Brown sandy silt of low plasticity (ML-CL)
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
13-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 1.50
1.50 1.95 SPT-1 11 0 19 73 8 26.8 19.9 6.9
2.25 2.55 UDS-1 2.66 1.73 1.55 11.3 UUT 0.60 7
3.00 3.45 SPT-2 12 25.7 18.5 7.2
4.50 4.95 SPT-3 15
5.25 5.55 UDS-2 0 23 70 7 26.2 19.2 7.0 2.67 1.82 1.62 12.3 UCS 0.82 -
6.00 6.45 SPT-4 16
7.50 7.95 SPT-5 26 24.7 17.5 7.2
8.25 8.55 UDS-3 0 18 77 5 1.89 1.67 13.1 UCS 1.20 -
9.00 9.45 SPT-6 53 24.5 18.6 5.9 2.65
10.00 10.45 SPT-7 71 10.45
Grain Size Analysis Atterberg Limits
Spe
cific
Gra
vity
Density and Moisture Shear Tests
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
Project No. 17079 Date of Start: Date of Completion: 13-Jun-17Client: M/s. BSES Rajdhani Power Limited Termination Depth
(m): 10.45
Fill: Sandy silt with concret
Brown sandy silt of low plasticity (ML-CL)
SOIL PROFILE (BH-7)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 8
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
13-Jun-17
From
To Gra
vel (
%)
San
d (%
)
Silt
(%
)
Cla
y (%
)
Liqu
id (
%)
Pla
stic
(%
)
Pla
stic
ity In
dex
(%)
Bul
k D
ensi
ty
(gm
s/cm
3 )
Dry
Den
sity
(g
ms/
cm3 )
Moi
stur
e C
onte
nt
(%)
Type
of T
est
Coh
esio
n In
terc
ept,
'c' (
kg/c
m2 )
Ang
le o
f Int
erna
l Fr
ictio
n, f
(deg
rees
)
0.50 1.00 DS-1 24.9 17.2 7.7
1.50 1.95 SPT-1 27 6 24 63 7
2.25 2.55 UDS-1 25.8 18.9 6.9 2.65 1.72 1.58 8.6 UUT 0.60 8
3.00 3.45 SPT-2 19
4.50 4.95 SPT-3 32 4 23 67 6
5.25 5.55 UDS-2 6.00 25.2 19.6 5.6 2.66 1.78 1.63 9.2 UCS 0.77 -
6.00 6.45 SPT-4 58 N P -
7.50 7.95 SPT-5 47
8.25 8.55 DS-2 N P -
9.00 9.45 SPT-6 62 0 58 42 0 2.63
10.00 10.45 SPT-7 75 10.45 N P -
Grain Size Analysis Atterberg Limits
Spe
cific
Gra
vity
Density and Moisture Shear Tests
SOIL DESCRIPTION
Dep
th o
f Stra
ta, (
m)
Depth, m
Sam
ple
No.
Fiel
d V
alue
, N
Sym
bol
Project No. 17079 Date of Start: Date of Completion: 13-Jun-17Client: M/s. BSES Rajdhani Power Limited Termination Depth
(m): 10.45
Brown sandy silt of low plasticity (ML-CL)
Brown silty sand (SM)
SOIL PROFILE (BH-8)
Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Water Table (m): Not Met Sheet No. 9
UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +
10
SYMBOL DESCRIPTION
Sandy silt (ML)
Filled upSandy silt (CL)
LEGEND
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Sandy silt (ML-CL)Silty sand (SM)
Summary of Borehole Profiles
Dep
th, m
0
1
2
3
4
5
6
7
8
9
10
11
12
N-Value
10.45 m
BH-1
12
9
26
39
8
45
4.5m
90
10.45 m
N-ValueBH-2
13
7
44
16
5
56
4.5m
85
6.0m
1.5m
N-Value
10.45 m
BH-3
20
12
50
28
9
62
7.5m
87
1.5m
N-Value
10.45 m
BH-4
20
11
40
25
11
61
5.05m
82
9.0m
11
SYMBOL
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Sandy silt (ML-CL)Silty sand (SM)
Summary of Borehole Profiles
DESCRIPTION
Sandy silt (ML)
Filled upSandy silt (CL)
LEGEND
Dep
th, m
0
1
2
3
4
5
6
7
8
9
10
11
12
N-Value
10.45 m
BH-5
22
14
47
54
9
63
4.5m
87
N-Value
10.45 m
BH-8
32
19
47
58
27
62
4.5m
75
N-Value
10.45 m
BH-6
17
14
28
26
12
44
4.5m
66
1.5m
6.0m
N-Value
10.45 m
BH-7
15
12
26
16
11
53
51
1.5m
12
Symbol
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
BH-1
Borehole Number
BH-6BH-5BH-4
Borehole Details
Field SPT Values vs. Depth
BH-3BH-2
Standard Penetration Test IS : 2131-1981, RA-2007
0
1
2
3
4
5
6
7
8
9
10
11
12
0 10 20 30 40 50 60 70 80 90 100
Field SPT Value (N)
Dep
th, m
13
Symbol
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
BH-6BH-5BH-4BH-3
Borehole Details
Corrected SPT Values vs. Depth
Standard Penetration Test IS : 2131-1981, RA-2007
BH-2BH-1
Borehole Number
0
1
2
3
4
5
6
7
8
9
10
11
12
0 10 20 30 40 50 60 70 80 90 100
Corrected SPT Value (N")
Dep
th, m
14
Symbol
Borehole Number
Borehole Details
IS : 2131-1981, RA-2007
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Field SPT Values versus Depth
BH-7
Standard Penetration Test
BH-8
0
1
2
3
4
5
6
7
8
9
10
11
12
0 10 20 30 40 50 60 70 80 90 100
Field SPT Value (N)
Dep
th, m
15
Symbol
BH-8BH-7
Borehole Number
Borehole Details
IS : 2131-1981, RA-2007
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Corrected SPT Values versus Depth
Standard Penetration Test
0
1
2
3
4
5
6
7
8
9
10
11
12
0 10 20 30 40 50 60 70 80 90 100
Corrected SPT Value (N")
Dep
th, m
16
E-WE-W
(Reverse)
SE-NWSE-NW
(Reverse)
N-SN-S
(Reverse)
SW-NESW-NE
(Reverse)
6.1 6.0 9.5 9.4 9.1 9.0 9.3 9.3
15.7 15.8 17.0 16.8 16.8 16.7 16.3 16.3
24.6 24.0 27.0 26.4 25.8 25.4 24.0 23.9
38.5 38.7 45.2 45.2 36.2 37.4 37.7 37.2
30.9 30.5 41.5 40.7 54.7 55.4 33.9 33.9
35.7 37.2 35.2 34.2 30.7 31.2 37.7 37.2
24.5 23.2 28.3 27.6 28.3 27.6 31.4 30.810.0
0.5
Electrode Spacing, m
ERT-1
Test Details
Test No. :
Apparent Resistivity, Ohm-m
8.0
1.0
6.0
Apparent Resistivity Values & Curves
29 2727
26.1 ohm-m
2525 29 2929
IS: 3043-1987, RA-2006
4.0
Electrical Resistivity Test No.: ERT-1
2.0
Mean Resistivity
Mean Resistivity Value, ohm-m :
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
1
10
100
1000
0 2 4 6 8 10 12
Electrode Spacing , m
App
aren
t Res
istiv
ity ,O
hm-m
E-W E-W (Reverse)
SE-NW SE-NW (Reverse)
N-S N-S (Reverse)
SW-NE SW-NE (Reverse)
17
26.1 ohm-m
Test Details
Test No. : ERT-1
Total Area of Polygon :
Polar Resistivity Curves
2135
Radius of Equivalent Circle=Mean Resistivity :
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Electrical Resistivity Test No.: ERT-1IS: 3043-1987, RA-2006
20.6, -20.6
0.0, -29.0
-20.2, 20.2
0.0, 28.8
19.0, 19.0
-19.2, -19.2
-25.1, 0.0 25.1, 0.0
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30W
N
SSESW
NW NE
E
18
GRAVEL SAND SILT CLAY
% % % %
1 0.50 5 24 65 6
1 4.50 0 56 44 0
1 10.00 0 78 22 0
Sandy silt ( ML-CL )
Silty sand (SM )
Silty sand (SM )
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Grain Size Analysis
DEPTH (m)SYMBOL DESCRIPTIONBH
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
19
GRAVEL SAND SILT CLAY
% % % %
2 2.25 3 22 68 7
2 5.25 0 36 61 3
2 10.00 6 15 72 7
DEPTH (m)SYMBOL DESCRIPTIONBH
Sandy silt ( ML-CL )
Sandy silt ( ML-CL )
Silty sand (SM )
Grain Size AnalysisSoil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New
Delhi.
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
20
GRAVEL SAND SILT CLAY
% % % %
3 1.50 0 18 74 8
3 5.25 0 24 69 7
3 10.00 5 15 71 9
Sandy silt ( ML-CL )
Sandy silt ( CL )
Sandy silt ( ML-CL )
Grain Size AnalysisSoil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New
Delhi.
DEPTH (m)SYMBOL DESCRIPTIONBH
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
21
GRAVEL SAND SILT CLAY
% % % %
4 3.00 0 22 71 7
4 5.25 3 36 58 3
4 10.00 6 28 61 5
DEPTH (m)SYMBOL DESCRIPTIONBH
Sandy silt ( ML-CL )
Sandy silt ( ML-CL )
Sandy silt ( ML )
Grain Size AnalysisSoil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New
Delhi.
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
22
GRAVEL SAND SILT CLAY
% % % %
5 1.50 0 33 62 5
5 4.50 0 61 39 0
5 7.50 0 63 37 0
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.
Sandy silt ( ML-CL )
Silty sand (SM )
Silty sand (SM )
Grain Size Analysis
DEPTH (m)SYMBOL DESCRIPTIONBH
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
23
GRAVEL SAND SILT CLAY
% % % %
6 2.25 0 19 73 8
6 4.50 0 63 37 0
6 9.00 4 26 64 6
DEPTH (m)SYMBOL DESCRIPTIONBH
Sandy silt ( ML-CL )
Sandy silt ( ML-CL )
Silty sand (SM )
Grain Size AnalysisSoil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New
Delhi.
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
24
GRAVEL SAND SILT CLAY
% % % %
7 1.50 0 19 73 8
7 5.25 0 23 70 7
7 8.25 0 18 77 5
Sandy silt ( ML-CL )
Sandy silt ( ML-CL )
Sandy silt ( ML-CL )
Grain Size AnalysisSoil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New
Delhi.
DEPTH (m)SYMBOL DESCRIPTIONBH
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
25
GRAVEL SAND SILT CLAY
% % % %
8 1.50 6 24 63 7
8 4.50 4 23 67 6
8 9.00 0 58 42 0
DEPTH (m)SYMBOL DESCRIPTIONBH
Sandy silt ( ML-CL )
Silty sand (SM )
Sandy silt ( ML-CL )
Grain Size AnalysisSoil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New
Delhi.
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Particle Size, mm
Perc
ent F
iner
by
Wei
ght
GRAVELFINE MEDIUM
S I L TCOARSE
S A N DCLAY
26
SOIL :
Borehole No.
pH Value
1 7.4
2 7.4
3 7.6
4 7.5
5 7.3
6 7.8
7 7.1
8 7.7
3.00 0.11 0.02
3.00 0.12 0.03
0.00 0.08 0.02
2.25 0.09 0.03
1.50 0.10 0.01
CHEMICAL TEST RESULTS
Depth, (m)
Sulphate Content ,% (SO3)
Chloride Content ,%
2.25 0.07 0.01
3.00 0.10 0.01
1.50 0.12 0.03
Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.