INTERIM REPORT

NCD/G/RPPL/4538A (1)/2023	12 April 2023

Renew Power Pvt Ltd.,

Sub :	G(D) 4538A Conducting Geotechnical Investigation for the Proposed Solar Power Plant 600MW SECI - IV RAJ 600MW, Rajasthan

INTRODUCTION

ReNew Power Pvt Ltd are in the process of constructing 600 MW SECI-IV RAJ solar project at Village Bhinajpura/Hastinapur, Tehsil Bhaniyana, District Jaisalmer, Rajasthan.

The stipulated scope of work for solar panels consisted of conducting boreholes down to a depth of 3m below the existing ground level in soil/refusal/rock strata at twelve locations.

This interim report is based on the geotechnical investigations results for a part of the investigations i.e. along with the results and analysis of the investigations and the recommendations thereof.

BOREHOLE INVESTIGATION :

All the twelve boreholes had been progressed down to the stipulated depth. The refusal depth, termination depths and coordinates of the four are as follows :

BHNo.	Refusal

depth (m) below EGL	Termination Depth (m) below EGL	Boreholes Coordinates (m)
X	Y
1	2.5	3	758937.46	2940287.00
2	2.5	3	759280.39	2939930.92
3	2.5	3	759031.90	2939984.66
4	2.5	3	759384.33	2939720.30
5	2.5	3	759478.66	2939531.39
6	1.5	3	759508.73	2939342.49
7	3.5	3.5	759661.66	2939153.59
8	4	4	759935.44	2938964.69
9	5	5	760158.71	2938775.79
10	3	3	760415.91	2938586.89
11	3.2	3.5	760377.25	2938397.98
12	2.2	3	760281.04	2938209.08

The results of the boreholes investigations indicate that the subsoil strata generally consists of silty sandy soils with significant percentages of gravel, pebble, conglomerate down to the depth of refusal strata below which substrata consists of highly weathered sandstone/ conglomerate down to the maximum depth investigated i.e. 5m below the existing ground level. The grain size distributions of the soil samples in the six boreholes have been presented in the form of grain size analysis curves in figs. 3a & 3b.

Ground water table had not been encountered in any of the boreholes down to the maximum depth investigated i.e. 5m below the existing ground level.

The standard penetration test values (N-values) vary between 22 and 97. The observed N-values indicate that the subsoil is in a medium dense state down to the depth of refusal strata.

The subsoil strata is non-plastic down to the depth of refusal strata.

The proposed structures are supporting structures for Solar Panels. Considering this, medium heavy can be anticipated on the foundations. Based on the above results and the probable loads on the foundations, the following recommendations are being made.

RECOMMENDATION :

Considering the above, the proposed structures can be supported over Short bored piles.

The parameters considered for the analysis of the pile capacities are given below :

S. No.	Parameter	Value
1	Effective length (m)	1.2 to 1.6
2	Cohesion (kg/cm²)	0.05
3	Angle of shearing resistance	32o
4	Density (g/cm3)	1.8
5	SPT Value at pile tip	25
6	Factor of safety for pile vertical capacity	2.5

The following pile capacity can be considered for 300mm diameter and various effective lengths of piles.

Pile Dia (mm)	Pile Effective Length (m)	Pile Vertical Load Capacity

(tons)	Safe Uplift Capacity of Pile (tons)	Safe Lateral Load Capacity (tons)

300	1.2	10	0.9	0.4
1.3	10	1	0.5
1.4	10	1.1	0.6
1.5	10	1.2	0.7
1.6	10	1.3	0.8

NOTE :	Factor of safety for determination of uplift capacity has been considered as 2 whereas factor of safety for determination of lateral capacity has been considered as 3.

The self weight of the pile has been added for the evaluation for the pile uplift capacities.

We hope you find this in order.

Thanking you,

Yours sincerely,

Y.S. Rana

Executive Consultant

encls :

1.	Compile Soil Profile

2.	Soil Profile Tables

3.	Grain Size Analysis Curves