What is Important of geotechnical site investigation ,Geotechnical site investigation report in civil technology?

1                  Important of geotechnical site investigation

  SITE GEOTECHNICS

1.          LITHOLOGY AND STRATIGRAPHY

 

The geotechnical investigations carried out at the site have revealed the presence of the following distinct lithological units:

Excevation work

 

BORE HOLE # 1

Plot No. 01

 

0.0	to	38.0 ft. depth	=	Sandy silty clay, brown, very stiff to hard, trace concretion,
				trace gravels, moist (CL-ML)
38.0	to	70.0 ft. depth	=	Shale with siltstone, reddish brown, loose to medium, moist
				(Sh)
70.0	to	85.0 ft. depth	=	Siltstone, reddish brown, loose to medium, slightly
				weathered, fractured (SiltSt)
85.0	to	100.0 ft. depth	=	Shale with siltstone, reddish brown, loose to medium, moist
				(Sh)

BORE HOLE # 2

 

 

0.0	to	35.0 ft. depth	=	Sandy silty clay, brown, hard, trace gravels and pebble,
				trace to little concretion, moist (CL-ML)
35.0	to	55.0 ft. depth	=	Shale, medium to hard, reddish brown, moist (Sh)
55.0	to	70.0 ft. depth	=	Siltstone, reddish brown, loose to medium, slightly
				weathered, fractured (SiltSt)
70.0	to	100.0 ft. depth	=	Shale, reddish brown, loose to medium, moist (Sh)

 

BORE HOLE # 3

 

 

0.0	to	11.0 ft. depth	=	Shale with silty clay, brown, very stiff, trace concretion,
				moist (CL-ML)
11.0	to	27.0 ft. depth	=	Clayey sand, brownish grey, medium dense, fine to medium
				grained, trace gravels, moist (SP-SC)
27.0	to	39.0 ft. depth	=	Sandy silty clay, blackish brown, hard, trace to little
				concretion, trace pieces of shale, moist (CL-ML)
39.0	to	100.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)

 

BORE HOLE # 4

 

 

0.0	to    35.0 ft. depth	=	Sandy silty clay, dark brown, hard, trace concretion, trace
			gravels, moist (CL-ML)
35.0	to    41.0 ft. depth	=	Sand stone, grey, loose to medium, fine grained, slightly
			weathered, fractured (SA)

 

 

41.0	to	48.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)
48.0	to	63.0 ft. depth	=	Siltstone, reddish brown, loose to medium, fine grained,
				slightly weathered, fractured (SiltSt)
63.0	to	100.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)

 

BORE HOLE # 5

 

 

0.0	to    35.0 ft. depth	=	Sandy silty clay, brown, hard, trace concretion, trace
			gravels, moist (CL-ML)
35.0	to    100.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)

 

BORE HOLE # 6

 

 

0.0	to	38.0 ft. depth	=	Shale with silty clay and concretion, reddish brown, medium
				to hard, moist (CL-ML)
38.0	to	52.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)
52.0	to	100.0 ft. depth	=	Silt stone, reddish brown, medium to hard, fracture (SiltSt)

 

 

 

BORE HOLE # 1

Plot No. 02

 

0.0	to	19.0 ft. depth	=	Silty clay, brown, hard, trace concretion, trace gravels,
				moist (CL-ML)
19.0	to	24.0 ft. depth	=	Gravels and pebbles, grey, very dense, gravels are rounded
				to sub rounded, moist (GP)
24.0	to	39.0 ft. depth	=	Sandy silty clay, brown, hard, trace concretion with gravels,
				moist (CL-ML)
39.0	to	46.0 ft. depth	=	Sandstone, grey, very dense, slightly weathered, fine to
				medium grained, fractured (SA)
46.0	to	100.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)

 

BORE HOLE # 2

 

 

0.0	to    38.0 ft. depth	=	Sandy silty clay, brown, hard, trace concretion with gravels,
			moist (CL-ML)
38.0	to    100.0 ft. depth	=	Shale, reddish brown, medium to hard (Sh)

 

BORE HOLE # 3

 

 

0.0	to    24.0 ft. depth	=	Sandy silty clay, brown, hard, trace concretion with gravels,
			moist (CL-ML)
22.0	to    24.0 ft. depth	=	Gravels and pebbles, grey, very dense, gravels are rounded
			to sub rounded, moist (GP)

 

 

24.0	to    41.0 ft. depth	=	Sandy silty clay, brown, hard, trace concretion with gravels,
			moist (CL-ML)
41.0	to    100.0 ft. depth	=	Siltstone, reddish brown, loose to medium, slightly
			weathered, fractured (SiltSt)

 

BORE HOLE # 4

 

 

0.0	to	35.0 ft. depth	=	Sandy silty clay, dark brown, hard, trace concretion, moist
				(CL-ML)
35.0	to	47.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)
47.0	to	63.0 ft. depth	=	Siltstone, reddish brown, loose to medium, fine grained,
				slightly weathered, fractured (SiltSt)
63.0	to	100.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)

 

BORE HOLE # 5

 

 

0.0	to	35.0 ft. depth	=	Sandy silty clay, brown, hard, trace concretion with gravels,
				moist (CL-ML)
35.0	to	70.0 ft. depth	=	Siltstone, reddish brown, medium to hard, slightly
				weathered, fractured (SiltSt)
70.0	to	81.0 ft. depth	=	Shale, reddish brown, hard, moist (Sh)
81.0	to	100.0 ft. depth	=	Siltstone, reddish brown, medium to hard, slightly
				weathered, fractured (SiltSt)

 

The subsoil profiles developed on the basis of revealed stratigraphy from Bore hole as appended to this report in the form of Borehole logs are enclosed at Appendix-B.

 

1.2             NATURAL MOISTURE CONTENT

 

The natural moisture content (NMC) recorded on the samples extracted from the depths indicates the value varying from 8 % to 18 %.

 

1.3             SEISMICITY

 

The project site is located in seismic zone of 2B as per “Revised Building Code 2007 (Seismic Provisions)” with peak ground acceleration of 0.16 g to 0.24 g.

 

1.4             GROUNDWATER

 

Groundwater was not encountered at site during the site investigation in March 2019.