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.
Comments