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.

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1 . 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 PHONE: , , MOB: , raoraoengg@rediffmail.com, raogr@yahoo.com

2 . June 17 th, 2017 Project No M/s. BSES Rajdhani Power Limited 1 st Floor, C-Block, BSCS Bhawan, Nehru Place, Delhi 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/ dated June 2 nd, 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)

3 RAO ENGINEERING ENTERPRISES GEOTECHNICAL REPORT TABLE OF CONTENTS Page No 1.0 INTRODUCTION Project Description Aim of Soil Investigation Scope of Work FIELD INVESTIGATIONS Soil Borings Groundwater Electrical Resistivity Tests LABORATORY TESTS GENERAL SITE CONDITIONS Site Stratigraphy Groundwater FIELD TEST RESULTS Electrical Resistivity Test Result FOUNDATION ANALYSIS General Liquefaction Susceptibility Assessment Foundation Type and Depth Allowable Bearing Pressure Sample Calculations RECOMMENDATIONS CHEMICAL RESULTS 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 Project No i

4 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 7 th, 2017 issued to us. A layout plan illustrating the test locations of our field investigation is presented on Fig 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 Page 1 of 8

5 RAO ENGINEERING ENTERPRISES GEOTECHNICAL REPORT occurred, casing was used to keep the borehole stable. The work was in general accordance with IS: 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: 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: 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: I 1 AND I 2 ARE CURRENT ELECTRODES P 1 AND P 2 ARE POTENTIAL ELECTRODES Project No Page 2 of 8

6 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 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: where: ρ = 2 π a R 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 LABORATORY TESTS Laboratory tests have been conducted on various selected soil samples in the laboratory: Laboratory Test Bulk Density Natural moisture content Specific Gravity Grain size analysis Liquid Limit and Plastic Limit Unconfined compression test Unconsolidated Undrained triaxial shear test ph value Chemical Analysis Sulphates of soil Chlorides IS Code Referred By calculations IS : 2720 (Part-2)-1973, RA-2010 IS : 2720 (Part-3)-1980, RA-2007 IS : 2720 (Part-4)-1985, RA-2010 IS : 2720 (Part-5)-1985, RA-2010 IS : 2720 (Part-10)-1991, RA-2010 IS : 2720 (Part-11)-1993, RA-2007 IS : 2720 (Part 26)-1987, RA-2007 IS : 2720 (Part-27)-1977, RA-2010 IS : 3025 (Part-32)-1988, RA 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 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 m. Project No Page 3 of 8

7 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 Groundwater Based on our measurements in the completed boreholes, groundwater was not met to the final explored depth of 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: 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 Moderately Corrosive Fig. 8 & 9 * As per Clause of Amendment No. 2 to IS: , dated January 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 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 Page 4 of 8

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: , liquefaction is likely to occur in loose fine sand below water table. Since groundwater was not met to the final explored depth of 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) (b) Settlement criteria Shear failure criterion Shear failure condition as per I.S 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), Project No Page 5 of 8

9 RAO ENGINEERING ENTERPRISES GEOTECHNICAL REPORT 6.5 Sample Calculations Type of foundation Depth of foundation Width of foundation Open foundation 2.0 m. below EGL 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 47.7 mm 0.6 for Worst condition Allowable bearing pressure Corresponding to 50 mm allowable Settlement T/m² II. SHEAR FAILURE CRITERION The bearing capacity equation used is as follows: q net safe = 1 [cn c ζ c d c + q(n q -1) ζ q d q Bϒ N γ ζ γ d ϒ R w ] F Where: q net safe = safe net bearing capacity of soil based on the shear failure criterion. q = overburden pressure R w = water table correction factor F = Factor of safety, taken as equal to 2.5 in accordance with IS: ζ c,ζ q,ζ γ = Shape factors. For Strip footings, ζ c = ζ q = ζ γ = 1 For Square footing, ζ c = 1.3, ζ q = 1.2, ζ γ = 0.6 d c,d q, d γ = Depth factors For φ 10, d c = tan (45 + φ / 2) D / B, d q = d γ = 1 For φ > 10, d q = d γ = 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 : N c = 6.81 N q = 1.72 N γ = 0.57 ' ' ' Local Shear Failure : N c = 6.19 N q = 1.43 N γ = 0.34 Project No Page 6 of 8

10 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 m depth. Foundation Depth below existing ground level, m Total Settlement = 40 mm Recommended Net Allowable Bearing Pressure, T/m² Total Settlement = 50 mm 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-toedge 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 percent sulphates and percent chlorides. The ph value of soil is IS: 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 (SO 3 ). 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: 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 Page 7 of 8

11 RAO ENGINEERING ENTERPRISES GEOTECHNICAL REPORT (1) The cement content in foundations concrete should be at least 280 kg/m 3. (2) Water cement ratio in foundation concrete should generally not exceed (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. Project No Page 8 of 8

12 1 BH-8 BH-5 BH-6 BH-7 ERT-1 BH-3 BH-4 BH-1 BH-2 SYMBOL L E G E N D TYPE OF TEST Borehole (BH) Plan of Field Investigations Electrical Resisitivity Test (ERT) Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

13 Depth, m Project: Client: M/s. BSES Rajdhani Power Limited Date of Start: 10-Jun-17 Date of Completion: SOIL PROFILE (BH-1) Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. 10-Jun-17 Grain Size Analysis Water Table (m): Not Met Sheet No. Termination Depth (m): Atterberg Limits Project No. Density and Moisture Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS SPT Brown sandy silt of low plasticity (ML-CL) UDS UUT SPT SPT N P DS SPT-4 39 N P SPT-5 26 Brown silty sand (SM) DS-3 N P SPT SPT N P UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

14 Depth, m Project: Client: M/s. BSES Rajdhani Power Limited SOIL PROFILE (BH-2) Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Date of Start: 11-Jun-17 Date of Completion: 11-Jun-17 Grain Size Analysis Water Table (m): Not Met Sheet No. 3 Termination Depth (m): Atterberg Limits Project No. Density and Moisture Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS-1 Fill: Silty sand SPT UDS-1 Grey sandy silt of low plasticity (ML-CL) UUT SPT SPT-3 13 N P - Grey sandy silt of non plasticity (ML) DS N p SPT SPT UDS-2 Brown sandy silt of low plasticity (ML-CL) UCS SPT SPT UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

15 Depth, m Project: Client: SOIL PROFILE (BH-3) Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. M/s. BSES Rajdhani Power Limited Date of Start: 11-Jun-17 Date of Completion: 11-Jun-17 Grain Size Analysis Water Table (m): Not Met Sheet No. 4 Termination Depth (m): Atterberg Limits Project No Density and Moisture Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS-1 Fill: Silty sand SPT UDS UUT SPT-2 12 Grey sandy silt of low plasticity (ML-CL) SPT UDS UCS SPT SPT UDS UCS Brown sandy silt of low plasticity (CL) SPT SPT UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

16 Depth, m Project: Client: SOIL PROFILE (BH-4) Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. M/s. BSES Rajdhani Power Limited Date of Start: 11-Jun-17 Date of Completion: 11-Jun-17 Grain Size Analysis Water Table (m): Not Met Sheet No. 5 Termination Depth (m): Atterberg Limits Project No Density and Moisture Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS SPT UDS-1 Grey sandy silt of low plasticity (ML-CL) UUT SPT SPT UDS N P UCS SPT-4 39 Brown sandy silt of non plasticity (ML) SPT-5 26 N P DS N P SPT Brown sandy silt of low plasticity (ML-CL) SPT UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

17 SOIL PROFILE (BH-5) Depth, m Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Client: M/s. BSES Rajdhani Power Limited Termination Depth Date of Start: 12-Jun-17 Date of Completion: 12-Jun-17 (m): Grain Size Analysis Water Table (m): Not Met Sheet No. 6 Atterberg Limits Density and Moisture Project No Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS SPT Brown sandy silt of low plasticity (ML-CL) UDS UUT SPT SPT N P DS SPT-4 54 N P SPT-5 47 Brown silty sand (SM) DS-3 N P SPT SPT N P UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

18 Depth, m Project: Client: SOIL PROFILE (BH-6) Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. M/s. BSES Rajdhani Power Limited Date of Start: 12-Jun-17 Date of Completion: 12-Jun-17 Grain Size Analysis Water Table (m): Not Met Sheet No. 7 Termination Depth (m): Atterberg Limits Project No Density and Moisture Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS-1 Fill: Silty sand SPT UDS-1 Brown sandy silt of low plasticity (ML-CL) UUT SPT SPT N P Brown silty sand (SM) DS N P SPT SPT UDS-2 Brown sandy silt of low plasticity (ML-CL) UCS SPT SPT UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

19 SOIL PROFILE (BH-7) Depth, m Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Client: M/s. BSES Rajdhani Power Limited Termination Depth Date of Start: 13-Jun-17 Date of Completion: 13-Jun-17 (m): Grain Size Analysis Water Table (m): Not Met Sheet No. 8 Atterberg Limits Density and Moisture Project No Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS-1 Fill: Sandy silt with concret SPT UDS UUT SPT SPT UDS UCS Brown sandy silt of low plasticity (ML-CL) SPT SPT UDS UCS SPT SPT UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

20 SOIL PROFILE (BH-8) Depth, m Project: Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi. Client: M/s. BSES Rajdhani Power Limited Termination Depth Date of Start: 13-Jun-17 Date of Completion: 13-Jun-17 (m): Grain Size Analysis Water Table (m): Not Met Sheet No. 9 Atterberg Limits Density and Moisture Project No Shear Tests From To Sample No. Field Value, N Symbol SOIL DESCRIPTION Depth of Strata, (m) Gravel (%) Sand (%) Silt (%) Clay (%) Liquid (%) Plastic (%) Plasticity Index (%) Specific Gravity Bulk Density (gms/cm 3 ) Dry Density (gms/cm 3 ) Moisture Content (%) Type of Test Cohesion Intercept, 'c' (kg/cm 2 ) Angle of Internal Friction, f (degrees) DS SPT UDS UUT Brown sandy silt of low plasticity (ML-CL) SPT SPT UDS UCS SPT-4 58 N P SPT DS-2 Brown silty sand (SM) N P SPT SPT N P - UUT : Unconsolidated Undrained Triaxial Shear Tes DST: Drained Direct Shear Test, UCS : Unconfined Compressive Strength Remolded Sample +

21 10 0 BH-1 N-Value BH-2 N-Value BH-3 N-Value BH-4 N-Value m 5 1.5m m m m Depth, m m m m m m m m 12 SYMBOL LEGEND DESCRIPTION Filled up Sandy silt (CL) Sandy silt (ML) Silty sand (SM) Sandy silt (ML-CL) Summary of Borehole Profiles Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

22 11 0 BH-5 N-Value BH-6 N-Value BH-7 N-Value BH-8 N-Value m m m m Depth, m m m m m m m 12 SYMBOL Filled up Sandy silt (CL) Sandy silt (ML) LEGEND Silty sand (SM) Sandy silt (ML-CL) DESCRIPTION Summary of Borehole Profiles Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

23 12 Standard Penetration Test IS : , RA-2007 Borehole Details Symbol Borehole Number BH-1 BH-2 BH-3 BH-4 BH-5 BH-6 Field SPT Value (N) Depth, m Field SPT Values vs. Depth Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

24 13 Standard Penetration Test IS : , RA-2007 Borehole Details Symbol Borehole Number BH-1 BH-2 BH-3 BH-4 BH-5 BH-6 Corrected SPT Value (N") Depth, m Corrected SPT Values vs. Depth Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

25 14 Standard Penetration Test IS : , RA-2007 Borehole Details Symbol Borehole Number BH-7 BH-8 Field SPT Value (N) Depth, m Field SPT Values versus Depth Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

26 15 Standard Penetration Test IS : , RA-2007 Borehole Details Symbol Borehole Number BH-7 BH-8 Corrected SPT Value (N") Depth, m Corrected SPT Values versus Depth Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

27 16 Electrical Resistivity Test No.: ERT-1 IS: , RA-2006 Test Details Test No. : ERT E-W E-W (Reverse) SE-NW SE-NW (Reverse) Apparent Resistivity,Ohm-m N-S SW-NE N-S (Reverse) SW-NE (Reverse) Electrode Spacing, m Electrode Spacing, m E-W E-W (Reverse ) Apparent Resistivity, Ohm-m SE-NW SE-NW (Reverse ) N-S N-S (Reverse ) SW-NE SW-NE (Reverse ) Mean Resistivity Mean Resistivity Value, ohm-m : 26.1 ohm-m Apparent Resistivity Values & Curves Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

28 17 Electrical Resistivity Test No.: ERT-1 IS: , RA-2006 Test Details Test No. : ERT-1 NW , N 28.8 NE , , , , 0.0 W E , , SW , S SE Total Area of Polygon : Radius of Equivalent Circle=Mean Resistivity : ohm-m Polar Resistivity Curves Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

29 18 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Silty sand (SM ) Silty sand (SM ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

30 19 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Silty sand (SM ) Sandy silt ( ML-CL ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

31 20 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Sandy silt ( ML-CL ) Sandy silt ( CL ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

32 21 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Sandy silt ( ML ) Sandy silt ( ML-CL ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

33 22 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Silty sand (SM ) Silty sand (SM ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

34 23 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Silty sand (SM ) Sandy silt ( ML-CL ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

35 24 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Sandy silt ( ML-CL ) Sandy silt ( ML-CL ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

36 25 CLAY S I L T FINE S A N D MEDIUM COARSE GRAVEL Percent Finer by Weight Particle Size, mm SYMBOL BH DEPTH (m) DESCRIPTION GRAVEL SAND SILT CLAY % % % % Sandy silt ( ML-CL ) Sandy silt ( ML-CL ) Silty sand (SM ) Grain Size Analysis Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.

37 26 CHEMICAL TEST RESULTS SOIL : Borehole No. Depth, (m) Sulphate Content,% (SO 3 ) Chloride Content,% ph Value Soil Investigation Work for Proposed 2 X 25 MVA 66/11kV G-1 Sub-Station at Dwarka, New Delhi.