Oskarshamn site investigation RAMAC logging in boreholes ...
GEOTECHNICAL INVESTIGATION REPORT · at change of soil Strata in different Boreholes and S.P.T soil...
Transcript of GEOTECHNICAL INVESTIGATION REPORT · at change of soil Strata in different Boreholes and S.P.T soil...
2017
GEOTECHNICAL INVESTIGATION REPORT
NAME OF THE PROJECT: GEOTECHNICAL INVESTIGATION AT STUDIES WORK
FOR ANDHRAPRADESH MEDTECH ZONE (AMTZ) VISHAKAPATNAM,
ANDHRAPRADESH LOCATION: Manufacturing unit Dist: Vishakapatnam, Andhrapradesh.
BOREHOLE : 15
Sample Ref. No: IDAX/QC/SOIL/38 Report Ref. No: IDAX/REP/ICRPL‐2017060007/EXP‐GI/2017‐18/415 TESTING AGENCY:
IDAX CONSULTING & RESEARCH PVT.LTD. Plot No. - 5016, Duplex-E, Brundaban Enclave, VSS Nagar, Bhubaneswar-751007, Odisha (INDIA). Tel: +91-674-3199991, 2360019, Fax: +91-674-2360019 E-mail: [email protected] Web: www.idaxconsulting.com
Date of Test: 30.06.2017 Date of Submission of Report: 06.07.2017
IDAX CONSULTING & RESEARCH PVT.LTD.
P R E F A C E
IDAX CONSULTING & RESEARCH PVT.LTD. is pleased to submit the geotechnical
investigation report for BH-15 STUDIES WORK FOR ANDHRAPRADESH
MEDTECH ZONE (AMTZ) VISHAKHAPATNAM, ANDHRAPRADESH . The
objective of this investigation is to ascertain the characteristics of Sub-soil to present
necessary information for sub-surface. It was endeavored to study in detail the sub-
surface conditions at the project site.
The general soil profiles and the geological stratification have been determined.
The field and laboratory works have been conducted as per relevant IS Codes.
This is to certify that the samples are collected from the proposed site for the Bore
Hole – 15 STUDIES WORK FOR ANDHRAPRADESH MEDTECH ZONE (AMTZ)
VISHAKHAPATINAM ,ANDHRAPRADESH by IDAX CONSULTING & RESEARCH
PVT.LTD. VSS NAGAR, BHUBANESWAR-75100. The laboratory tests have been
performed under the supervision of qualified personal, as per the Indian standards
and this report is prepared on the basis of these tests results and experts
experience.
For IDAX CONSULTING & RESEARCH PVT.LTD.
Engineer – Civil (Soil) (Head - Civil)
Er. Pratiksha Ray Er. Deepak Kumar Mallick
B. Tech- Civil B. Tech (Hons.) – Civil (IIT Kharagpur)
Project Code: 2017060007_GI Page 1 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
CONTENTS
Sl. No. PARTICULARS PAGES
01. INTRODUCTION 03
02. SCOPE OF WORK 03 - 04
03. DETAILS OF FIELD WORK 05
04. LABORATORY TESTS 06 - 07
05. DETERMINATION OF ALLOWABLE BEARING CAPACITY 07
06. ANALYSIS OF SUB-SOIL INVESTIGATION 07 - 08
07. FOUNDATION & RECOMMENDATION 09
08. LIMITATION 09
09. CLOSURE 09
BORE LOG & LAB TEST RESULTS OF BORE HOLE
ABP CALCULATIONS
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IDAX CONSULTING & RESEARCH PVT.LTD.
1. INTRODUCTION
Intending to provide a safe, sound and economical foundation system for the Sub - Soil
Exploration work for BH-15 at Studies Work For Andhrapradesh MediTech Zone
(AMTZ) Vishakhepatnam , Andhrapradesh and the work for conducting detailed soil
investigation work has been awarded to M/s IDAX CONSULTING & RESEARCH PRIVATE
LIMITED, VSS Nagar, Bhubaneswar-751007.
i. Objectives of Sub-soil Exploration
The objective of this Geo-technical investigation is to optimize the Foundation system for
proposed Project within the safe bearing capacity of the soil and allowable settlement, it
consists of the following
• Determination of type, size and depth of foundation- system by analyzing the soil
properties
• To suggest a conclusive recommendation for the type of foundation System to be adopted
which would be economically viable and structurally safe for the proposed structures of the
projects.
ii. Limitations of Investigation
The scope of Geo-technical exploration is confined within limitations of the framework of
agreement drawn between AMTZ LIMITED and M/s IDAX CONSULTING & RESEARCH
PRIVATE LIMITED, Bhubaneswar-751007. All the field and laboratory experiments have
been carried out as per the Technical specification of the client and the relevant Indian
Standard Code of practice. However the directions issued by the authority in this respect has
been given due emphasis during the sub soil exploration work.
2. SCOPE OF WORK
The scope of work comprises of conducting detail soil investigation, laboratory testing,
conducting and estimation of safe bearing capacity for the above proposed work on drilled
borehole as shown by the Engineer-in charge.
i. Nature of Investigation Work
The all investigation consists of the following:
Visual reconnaissance of the site.
Field Work-Drilling of bore hole up to the required depth.
Laboratory experiments, determination of soil parameters.
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Analysis of field and Laboratory data
Arriving at the conclusive decision on foundation system to be adopted in the present
case using Our Engineering judgment, based on the current practice. The detailed
Geo-technical investigation work that was carried out consists of two parts.
ii. Field Investigation:
The field investigation consists of the following methods
Location of One number of bore hole with due consultation with the authority.
Boring / drilling up to 10.0m depth below N.G.L or refusal.
Conducting standard penetration test (SPT) & Collection of undisturbed sample
(UDS) at the locations prefixed by the Engineer-in-charge.
Observation of the depth of water table in the Borehole.
Study of site condition and surroundings with regards to the need of the Project.
Taking observation of surrounding structure to observe any deficiency in safety.
Transportation of all soil samples to laboratory for analysis with proper care.
iii. Laboratory Tests:
The Laboratory tests for the sample collected are given below
Determination of Grain size analysis
Determination of soil moisture content
Determination of liquid limit
Determination of plastic limit
Determination of specific gravity
Determination of Allowable Bearing Pressure of Rock.
Project Code: 2017060007_GI Page 4 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
3. DETAILS OF FIELD WORK
i. Selection of Borehole:
One Bore-hole was selected by the Engineer in charge in order to obtain comprehensive
sub-soil data for this site with a provision of borings up to 10.0m depth as required as per
IS:1892 - 1979. For detailed laboratory investigation SPT is conducted @ 1.50 m intervals or
at change of soil Strata in different Boreholes and S.P.T soil samples were collected for
laboratory analysis. Disturbed representative, soil samples from all the Boreholes were
collected at 1.5 m. interval for different tests.
ii. Boring:
It is the main part of sub soil investigation work as the soil samples were collected for
different tests at different levels. The sub-soil exploration work at the proposed site was
carried out manually / mechanically using 150 mm diameter shell and auger manual
equipment in soft strata and power operated Mechanical boring in hard strata using diamond
cutter , as per IS : 1892 – 1979 .
iii. Standard Penetration Tests:
Standard penetration test plays a major role in sub soil investigation termination of safe
bearing capacity of soil in non cohesive type soil, particularly in non-cohesive granular sandy
soil and where the UDS could not be collected either due to high liquidity or non cohesive
nature of soil .The SPT tests were conducted as per IS: 2131-1981 respectively, in different
levels of the bore holes in a continuous manner using spilt-spoon samplers at locations
decided by Engineer-in-charge. The SPT sampler was lower inside the borehole after drilling
the required level and is driven by a 63.50 kg Rammer with a free fall of 750 mm. driving 450 mm in One stages 150 mm each and the number of blows for each 150mm penetration for
2nd & 3rd 150 mm drive recorded as “N”. Refusal was considered for N>100. The details of
location of test and SPT value [N] are presented in bore log data annexed separately.
iv. Ground Water Table:
During exploration work of the Location, 24hours observation it is found that the water table
is at 1.95m depth in BH-15 within the Boring depth from the existing ground level depending
on the location of boring. The water table may be fluctuating due to change of season.
Project Code: 2017060007_GI Page 5 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
4. LABORATORY TESTS
The laboratory-tests were conducted on selected representative disturbed / undisturbed soil
samples collected from different Borehole drilled at the proposed site. The tests include
Grain size analysis, Natural moisture content, D.F.S, Specific Gravity and Liquid limit, Plastic
limit, Plasticity index, Shear test, and Particles size distribution tests on representative soil
sample were also carried out. All the tests conducted confirming to the requirements of I.S
specification. The results of all these tests have been annexed separately.
i. Grain Size Analysis:
The grain size analysis of different soil samples were done as per the requirement of IS:
2720 (Pt-IV) 1985 – method of test for soil, Grain size analysis. The details of the test results
are shown test result sheet separately. The results of grain size analysis are used to classify
the soil in various depths of boreholes. The results of all these tests have been annexed
separately.
ii. Natural Moisture Content:
The natural moisture content was determined from different undisturbed samples of different
Boreholes at different depths, as per IS: 2720(Pt-II)-1973: Method of test for soil,
determination of Water content. It is used for determining specific gravity, optimum moisture
content, S.B.C, settlement of foundation system. The results of all these tests have been
annexed separately.
iii. Determination of Specific Gravity:
The specific gravity of the UDS / DS samples have been determined at different levels as
per IS: 2720 (Pt-III) - 1980. It is used for determining void ratio, porosity, saturated density,
S.B.C, settlement of foundation system. The results of all these tests have been annexed
separately.
iv. Determination of Void Ratio:
The void-ratio of the UDS / DS samples has been determined at different levels and the
results are shown separately. It is used for determining specific gravity, optimum moisture
content, S.B.C, settlement of foundation system. The results of all these tests have been
annexed separately.
Project Code: 2017060007_GI Page 6 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
v. Determination of Liquid Limit / Plastic Limit:
The liquid and plastic limits of soils were other index properties of soil have also been
determined as per the relevant as per IS: 2720(Pt-v)-1985 Code of practice. The liquid and
plastic limits of soil samples have been determined in the laboratory and it is used for
determining S.B.C, settlement of foundation system etc. The results of all these tests have
been annexed separately.
5. DETERMINATION OF SAFE BEARING CAPACITY (SBC)
Borehole Depth in mtrs.
Net Safe Bearing Gross Safe Bearing
Capacity in T/m2. Capacity in T/m2.
BH – 15
1.0 17.60 18.68
2.0 42.36 44.36
6. DETERMINATION OF ALLOWABLE BEARING PRESSURE OF
(ABP)
The allowable bearing pressure has been calculated as per IS: 2131 & IS: 8009 (Part-I) at
different depth from the existing ground level. The details of the calculation are annexed
separately.
Depth in mtrs.
Allowable Bearing Pressure in T/m2
25mm 40mm 75mm
2.0 17.64 28.23 52.93
3.0 22.12 35.38 66.35
Borehole-15
4.0 27.70 44.31 83.09
5.0 31.48 50.37 94.45
6.5 33.85 54.16 101.55
8.0 36.80 58.87 110.39
9.0 38.13 61.00 114.38
10.0 39.65 63.44 118.95
ANALYSIS OF THE SUB-SOIL INVESTIGATION
LOCATION: Manufacturing Unit
CO-ORDINATES:- N:1950610.736 E:729089.751 RL:39.0mtr
Project Code: 2017060007_GI Page 7 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
Borehole No. - 15 was have explored up to a depth of 10.0m the sub soil strata of the
Borehole is summarized as follows. LAYER- 1
The layer from 0.0m to 3.0m & 8.0m to 9.0m consists of Poorly graded clayey sand. The soil
sample in this layer was tested and results are summarized. The average weight was
Gravel- 7%, Sand- 60%, and Silt & Clay- 33%. The engineering classification of the soil is
SC as per IS: 1498-1970. LAYER- 2
The layer starts from 3.0m to 5.0m consists of Poorly Graded Gravel. The soil sample in this
layer was tested and results are summarized. The average weight was Gravel- 58%, Sand-
35%, and Silt & Clay- 7%. The engineering classification of the soil is GP as per IS: 1498-
1970. LAYER- 3
The layer starts from 5.0m to 6.50m consists of Poorly Graded Sand. The soil sample in this
layer was tested and results are summarized. The average weight was Gravel- 0%, Sand-
97%, and Silt & Clay- 3%. The engineering classification of the soil is SP as per IS: 1498-
1970. LAYER- 4
The layer starts from 6.50m to 8.0m & 9.0m to 10.0m consists of Poorly Graded Silty Sand.
The soil sample in this layer was tested and results are summarized. The average weight
was Gravel- 10%, Sand- 77%, and Silt & Clay- 13%. The engineering classification of the
soil is SM as per IS: 1498-1970.
7. FOUNDATION & RECOMMENDATION
Based on our field and laboratory investigation, the following recommendations are made:
i. The stratum encountered in different boreholes at different depths is presented in
respective soil profile sheets.
ii. The water table if encountered in the boreholes is also indicated in the soil profile
sheets.
iii. The depth of foundation shall be decided based on bearing capacity and uplift
resistance required.
iv. The recommended safe bearing capacity for the footing is computed based on
footing size as specified for suggested foundations are given below.
Project Code: 2017060007_GI Page 8 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
v. As per site condition which, visual observations of soil samples at site, field bore log
record, local geology of the area, type of sample received, laboratory classification of
soil samples and based on the experience of our Geotechnical Expert, it is
recommended to provide open foundation.
vi. The recommended safe bearing capacity for the footing is computed based on
footing size as specified for suggested foundations are given below. It is feasible to
provide open foundations. Open foundations can be placed at a depth of 3.0m below
the existing ground level. However for heavily loaded structures the foundation depth
can be increased as per the design load.
8. LIMITATION
The soil investigation has been carried out at the location chosen by the client.
Recommendations made in the report are hence valid only for these tests locations.
However if there is any change in subsoil conditions and properties at places beyond chosen
test locations, the soil consultants be contacted for further guidance.
9. CLOSURE
We appreciate the opportunity given to us to submit this draft report. This presented report is
based on observations and tests on samples collected from the boreholes as decided by the
client. In case any difference is noticed in the field subsoil strata and reported subsoil strata
during excavation please contact us before proceeding with further construction.
NB:
The above test reports are based on the sample received by our laboratory.
The test results relates only to the items tested.
The report shall not be reproduced except in full without the approval of the testing
laboratory.
For IDAX CONSULTING & RESEARCH PVT.LTD.
Engineer – Civil (Soil) (Head - Civil)
Er. Pratiksha Ray Er. Deepak Kumar Mallick
B. Tech- Civil B. Tech (Hons.) – Civil (IIT Kharagpur)
Project Code: 2017060007_GI Page 9 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
BORE LOG AND LAB TEST RESULTS OF BOREHOLE
Project Code: 2017060007_GI Page 10 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
BOREHOLE NO. - 15
Type of Soil Soil
Profile
0.00
Poorly Graded
clayey sand SC
Poorly Graded GP Gravel
Poorly Graded SP Sand
S Poorly Graded
silty sand M
Poorly Graded SC clayey sand
S
Poorly Graded
silty sand M
Depth SPT Value "N" Depth Plot
in mtrs.
0 10 20 30 4 0 50 60 7 0 80 90 0. 0
1.0
2.0
36
WL: 1.95m
3.0 42
4.0 51
5.0 57
6.0
64
7.0
8.0 74
9.0 82
10.0 84
N Type of
Core R.Q.D
Recovery
Sample (%)
(%)
N1 - N2 - N3
08-16-20 SPT Sample
10-20-22 SPT Sample
14-22-29 SPT Sample
18-25-32 SPT Sample
20-28-36 SPT Sample
22-32-42 SPT Sample
34-48-82 SPT Sample
27-34-50 SPT Sample
Project Code: 2017060007_GI Page 11 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
LIM
ITED
Sh
ear
Para
mete
rs
SOIL
SA
MP
LE
CLI
ENT:
AM
TZ
RL:
39.
0m
tr
Lim
its
D
en
sit
y t
es
t
TAB
LE ‐
1
SHEE
T R
ESU
LT O
F
Att
erb
erg
’s
SUM
MA
RY
an
aly
sis
LOC
AT
ION
: M
AN
UFA
CTU
RIN
G U
NIT
CO
‐OR
DIN
ATE
S:‐
N:1
95
61
0.7
36
E:7
29
08
9.7
51
Gra
in s
ize
o)
Void Ratio (e
Degree friction(φ) in
Angle of internal
2 Kg/cm
Cohesion ( C )
Type of Test
Specific gravity
content(%)
Natural Moisture
.gm/cc
Dry density in
.gm/cc
Bulk density in
Classification of Soil
(%) Plasticity Index
(%) Plastic Limit
(%) Liquid Limit
.S.F.D In %
075mm.( Passing)
Silty & Clay in % 075mm.)
425mm.( - Fine Sand in %
(2mm - .425mm)
Medium Sand in %
75mm.(4 - 2mm) Coarse Sand in %
(20mm - .475mm)
% Gravel in
(N) SPT Value
Type of sample
(m) Sampling Depth
LOCATION .No
0.5
3
21
0.1
8
DS
2.6
0
2.6
5
67
2.
2.6
6
722
.
722
.
2.5
6
672
.
2.6
6
2.6
8
20
.13
15.3
2
96
18
.
21.0
4
63
14
.
32
15
.
18.3
6
64
13
.
14.8
7
16.2
2
1
.72
7
1.9
9
2
SC
SC
SC
SC
GP
GP
SP
SM
SC
SM
13
13
13
12
Np
Np
Np
Np
Np
Np
21 19
20
19
NP
N
P
NP
NP
NP
NP
34
32
33
31
21
23
24
21
19
22
25
15
20
20
0
0
0
0
0
0
45.2
7
33.1
4
58
35
.
35.4
0
17
4.
44
4.
3.3
8
521
2.
14.4
0
13.2
9
40.1
2
12.0
4
879
.
7.6
4
028
.
635
.
42.8
6
14
20
. 12.3
6
9.6
8
13.6
5
21.0
5
23
15
. 13.4
9
14
20
.
79
12
. 40.1
1
11
23
. 19.8
7
21.0
4
0.9
6
30.1
2
962
8
. 33.7
9
781
2.
021
7
. 13.6
5
583
4. 40.1
3
45.2
1
0.0
0
3.6
5
36
10
. 9.6
8
89
54
.
12
60
. 0.0
0
659
.
13.2
4
10.7
8
-
- 36
42
51
57
65
74
82
84
DS
UD
S
SP
T
SP
T
SP
T
SP
T
SP
T
SP
T
SP
T
SP
T
0.0
1.0
02
.
3.0
04
.
05
.
6.5
08
.
09
.
10.0
No
.-1
5
B H
Project Code: 2017060007_GI Page 12 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
ALLOWABLE BEARING PRESSURE (ABP) AND
SAFE BEARING CAPACITY (SBC) OF SOIL
Project Code: 2017060007_GI Page 13 of 17
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CALCULATION OF ALLOWABLE BEARING
PRESSURE (ABP) FOR SETTLEMENT
CRITERIA
Project Name: GEOTECHNICAL INVESTIGATION FOR AMTZ LTD.
Location: MANUFACTURING UNIT Project Code: 2017060007-GI
Bore Hole No.: 15 Water Table: 1.95 mtrs
References Calculations
IS:8009 (Part-I) Input Data
Width / Diameter of Footing (Assumed) B = 2 mtr.
Length of Footing (Assumed) L = 2 mtr.
Shape of the Foundation = SQUARE
Influence Zone below foundation level = 3.00 mtr.
Type of Soil Strata = Elastic/Immediate (For Sandy & Granular Strata)
Type of Foundation = Flexible Foundation
Fig-11 Correction Factor for Rigidity Cr = 1.0
Water Table depth below GL = 1.95 mtr.
Fig-9 Water Table Factor to be Considered ? = Worst Condition Scenario (Submerged)
Fig-12 Fox's Depth Factor to be Considered ? Cd = YES
Depth to be ignored in Depth Factor Computation for loose soils, poorly
compacted backfill, scour, etc.
=
mtr.
0
N Value >3
S P T C o n d u c t e d a t D e p t h i n m t r .
Fiel
dSP
TVal
ue(N
)
W i d t h o f F o o t i n g i n M . ( A s s u m e d )
Cor
re
cte
dSP
Tv
alu
ed
uet
oo
ver
bur
de
npr
es
sur
eN
'()C
orr
ect
edS
PT
val
ue
as
per
Dil
ata
ncy
(N"
)
C o r r e s p o n d i n g s e t t l e m e n t i n m m f o r 1 k g / c m ( S ) i
C o r r e c t i o n F a c t o r f o r W a t e r T a b l e a s p e r I S : 8 0 0 9 ( P a r t - I ) C
FoxC
orre
ct
ion
for
Dep
thas
per
IS:8
0
09(P
a
rt- I),Fi
g-
12C
Fina
lCor
rect
edSe
ttlem
entin
mm
S=S
25A
BP
f
or
40A
BP
f
or
75A
BP
for
Correction of
- 9
Fi
g
i n
in
i n
SPT values
IS:8
0
09(P
art-
I)
w
d
m m s e t t l e m e n t T / m
m m s e t tl e m e n t T / m
mm
settl
emen
tT/m
(IS:2131-1981)
. . . 2
2
2
per
/C
w
as r
xC
2
d
xC
i
2.00 36 2 36.00 25.50 9.71 0.50 0.73 14.17 17.64 28.23 52.93
3.00 42 2 42.00 28.50 8.56 0.50 0.66 11.30 22.12 35.38 66.35
4.00 51 2 51.00 33.00 7.28 0.50 0.62 9.03 27.70 44.31 83.09
5.00 57 2 57.00 36.00 6.62 0.50 0.60 7.94 31.48 50.37 94.45
6.50 64 2 59.52 37.30 6.37 0.50 0.58 7.39 33.85 54.16 101.55
8.00 74 2 62.90 39.00 6.07 0.50 0.56 6.79 36.80 58.87 110.39
9.00 82 2 65.60 40.30 5.85 0.50 0.56 6.56 38.13 61.00 114.38
10.00 84 2 67.20 41.10 5.73 0.50 0.55 6.30 39.65 63.44 118.95
Project Code: 2017060007_GI Page 14 of 17
IDAX CONSULTING & RESEARCH PVT.LTD.
CALCULATION OF SAFE BEARING CAPACITY (SBC) Based on C, • Value
Project Name: GEOTECHNICAL INVESTIGATION FOR AMTZ LIMITED
Location: MANUFACTURING UNIT Project Code: 2017060007 - GI
Bore hole no.: 15 Depth of Sample: 1.00 mtrs Water Table: 1.95 mtrs
References Calculations
Input Data
Kg/cm2
Cohesion C = 0.18 Depth of Foundation Df = 1.00 mtr.
Angle of internal friction Ф = 21 Degrees
tan-1 ( 0.67 tanФ ) Ф' = 14 Degrees Bulk Density = 1.992 gm/cc Field Moisture Content = 15.32 %
Dry Density γd = 1.727 gm/cc Specific Gravity Gs = 2.65 Saturated Density γsat = 2.078 gm/cc Void Ratio e = 0.53
Submersible Density γs = 1.078 gm/cc
Width / Diameter of Footing (Assumed) B = 2 mtr.
Length of Footing (Assumed) L = 2 mtr.
Type of Footing = Continuous Strip Footing
Condition of Soil = Dense
Overburden Pressure
Kg/cm2
Kg/cm2 q = (Df x γs) / 1000 = 0.108 Bγ =( B x γs) / 1000 = 0.216
IS:6403, Table -1 Bearing Capacity Factors
Ф Nc Nq Nγ Ф' N'c N'q N'γ
21 16.008 7.252 6.488 14 10.454 3.646 2.364
IS:6403, Table -2 Shape Factors For Continuous Strip Footing Water Table Effect
Sc = 1.0 Sq = 1.0 Sγ = 1.0 W' = 0.5
Depth Factors Inclination Factors
dc = 1+0.2 x (Df/B) x tan(45+Ф/2) = 1.146 ic = iq = iγ = 1
dq = dγ = 1.073
Dense In case of general shear failure Net Ultimate Bearing Capacity
qd = CNcScdcic + q(Nq -1) Sqdqiq + 0.5 BγNγSγdγiγW'
= 3.302 + 0.723 + 0.375 = 4.400 Kg/cm2
Loose In case of Local shear failure Net Ultimate Bearing Capacity
q'd = 2/3 x CN'cScdcic + q(N'q -1)Sqdqiq + 0.5 BγN'γSγdγiγW'
= 0.000 + 0.000 + 0.000 = 0.000 Kg/cm2
Medium Net Ultimate Bearing Capacity Qnu = 4.400 Kg/cm2
Soil Bearing Capacity (SBC)= Qs = Qnu / FS + OB Factor of Safety (FS) = 2.5
Qs= 1.868 Kg/cm2 = 18.68 Tons/m2
Net Safe Bearing Capacity (NSBC)= Qns = Qnu / FS = Qs - OB
Qns= 1.760 Kg/cm2 = 17.60 Tons/m2
SBC = 18.68 Tons/m2 NSBC = 17.60 Tons/m
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Project Code: 2017060007_GI Page 15 of 17
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CALCULATION OF SAFE BEARING CAPACITY (SBC) Based on SPT "N" Value
Project Name: GEOTECHNICAL INVESTIGATION FOR AMTZ LIMITED
Location: MANUFACTURING UNIT Project Code: 2017060007 - GI
Bore Hole No.: 15 Depth of Sample: 2.00 mtrs Water Table: 1.95 mtrs
References Calculations
Input Data Field SPT Value N = 36
Depth of Foundation Df = 2.00 mtr. IS:2131, Fig-1 Corrected SPT value after over burden pressure N' = 46.800
Corrected SPT value after Dilatancy N" = 30.900
IS:6403, Fig-1 Angle of internal friction based on SPT "N" Value Ф = 35.7 Degrees
tan-1 ( 0.67 tanФ ) Ф' = 26 Degrees
Submersible density (Assumed) γs = 1.000 gm/cc Width / Diameter of Footing (Assumed) B = 2 mtr.
Length of Footing (Assumed) L = 2 mtr.
Type of Footing = Continuous Strip Footing
IS:6403, Fig-1 Condition of Soil = Dense
Overburden Pressure
Kg/cm2
Kg/cm2 q = (Df x γs) / 1000 = 0.200 Bγ =( B x γs) / 1000 = 0.200
IS:6403, Table -1 Bearing Capacity Factors
Ф Nc Nq Nγ Ф' N'c N'q N'γ
36 46.120 33.300 48.030 26 22.628 12.208 13.184
IS:6403, Table -2 Shape Factors For Continuous Strip Footing Water Table Effect
Sc = 1.0 Sq = 1.0 Sγ = 1.0 W' = 0.5
Depth Factors Inclination Factors
dc = 1+0.2 x (Df/B) x tan(45+Ф/2) = 1.39 ic = iq = iγ = 1
dq = dγ = 1.195
Dense
In case of general shear failure Net Ultimate Bearing Capacity
C = 0
qd = CNcScdcic +
q(Nq -1) Sqdqiq + 0.5 BγNγSγdγiγW'
= 0.000 + 7.720 + 2.870 = 10.590 Kg/cm2
Loose In case of Local shear failure Net Ultimate Bearing Capacity
q'd = 2/3 x CN'cScdcic + q(N'q -1)Sqdqiq + 0.5 BγN'γSγdγiγW'
= 0.000 + 0.000 + 0.000 = 0.000 Kg/cm2
Medium Net Ultimate Bearing Capacity Qnu = 10.590 Kg/cm2
Soil Bearing Capacity (SBC)= Qs = Qnu / FS + OB Factor of Safety (FS) = 2.5
Qs= 4.436 Kg/cm2 = 44.36 Tons/m2
Net Safe Bearing Capacity (NSBC)= Qns = Qnu / FS = Qs - OB
Qns= 4.236 Kg/cm2 = 42.36 Tons/m2
SBC = 44.36 Tons/m2 NSBC = 42.36 Tons/m
2
Project Code: 2017060007_GI Page 16 of 17
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RECORD OF BORING FROM FIELD
(TO BE GIVEN LETER)
Project Code: 2017060007_GI Page 17 of 17