GEOTECHNICAL INVESTIGATION REPORT - amtz.in · PDF file2017 geotechnical investigation report name of the project: geotechnical investigation studies work for andhrapradesh medtech

2017

GEOTECHNICAL INVESTIGATION REPORT

NAME OF THE PROJECT: GEOTECHNICAL INVESTIGATION STUDIES WORK FOR

ANDHRAPRADESH MEDTECH ZONE (AMTZ),

VISHAKHAPATNAM, ANDHRAPRADESH. LOCATION: RCC STRUCTURE

Borehole No.: BH‐11

Sample Ref. No: IDAX/QC/SOIL/40 Report Ref. No: IDAX/REP/ICRPL‐2017060007/EXP‐GI/2017‐18/443

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: 05.07.2017 to 06.07.2017 Date of Submission of Report: 13.07.2017

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-11 at Rcc Structure, 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 – 11 for Andhrapradesh MedTech Zone (AMTZ) at VR Center for BD design,

Vishakhapatnam, 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 20


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. ANALYSIS OF SUB-SOIL INVESTIGATION 07

06. DETERMINATION OF SAFE BEARING CAPACITY 07

07. DETERMINATION OF ALLOWABLE BEARING CAPACITY 08

08. FOUNDATION & RECOMMENDATION 08 - 09

09. LIMITATION 09

10. CLOSURE 09

BORE LOG & LAB TEST RESULTS OF BORE HOLE

ABP CALCULATIONS

RECORD OF BORING



1. INTRODUCTION

Intending to provide a safe, sound and economical foundation system for the Sub - Soil

Exploration work for BH-11 at Rcc Structure, Studies Work for Andhrapradesh

MedTech Zone (AMTZ), Vishakhapatnam, Andhrapradesh and the work for

conducting detailed soil investigation work has been awarded to 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 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.



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.



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 @ 1.0 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 1.0 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. 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 2.60m depth in BH-11 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.

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.

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.

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.

i. Core Recovery:

Rock core samples are kept in the same order as recovered from bore hole run wise

(marked arrow on cores in the increasing order of depth). The length of all core samples is


IDAX CONSULTING & RESEARCH PVT.LTD. measured. Core recovery is the ratio of the sum of the lengths of all the cores recovered

from drilling per run.

Core Recovery (%) = (Total length of core pieces recovered/Length of run x 100

It is expressed in percentage (%).

ii. RQD:

Rock Quality Designation indicates the quality of the rock. RQD is defined as the ratio of the

sum of the total length of the cores of length 10cm and longer recovered from the drilling of

the total length of the borehole is 1.5m.

RQD = (Total length of cores in pieces of 10cm length or longer/length of the run) x 100

It is expressed in percentage (%).

iii. Unconfined compressive strength of rock specimens:

As soon as the rock core samples were received in the laboratory, Core Recovery

percentages and RQD percentages were determined. Then core samples which were longer

than the diameter that was 54mm were selected for preparation of specific specimens as per

IS: 9143-1979 in the ratio of length : diameter = 1:1 and correction factors applied ( since

limited intact rock core sampling was possible). Then the specimens were tested for

unconfined compressive strength.

5. ANALYSIS OF THE SUB-SOIL INVESTIGATION LOCATION: Vishakhapatnam, Andhrapradesh CO-ORDINATES:- N: 1950374.273 , E: 728883.568 RL: 38.0mtr.

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 starts from 0.0m to 0.50m & 5.0m to 8.0m consists of ‘Medium Plastic Silty Clay’.

The soil sample in this layer was tested and results are summarized. The average weight

was Gravel- 0%, Sand- 41%, and Silt & Clay- 59%. The engineering classification of the soil

is CI as per IS: 1498-1970. LAYER- 2 The layer starts from 0.5m to 5.0m consists of ‘Poorly Graded Clayey Sand’. The soil sample

in this layer was tested and results are summarized. The average weight was Gravel- 2%,

Sand- 61%, and Silt & Clay- 37%. The engineering classification of the soil is SC as per IS:

1498-1970. Project Code: 2017060007_GI Page 7 of 20

Borehole No. - 16


LAYER- 3

The layer starts from 8.0m to 10.0m consists of’ Poorly Graded Sand’. The soil sample in

this layer was tested and results are summarized. The average weight was Gravel- 0%,

Sand- 96%, and Silt & Clay- 4%. The engineering classification of the soil is SP as per IS:

1498-1970.

6. DETERMINATION OF SAFE BEARING CAPACITY (SBC)

Net Safe Bearing Gross Safe Bearing

Borehole Depth in mtrs.

2

Capacity in T/m . Capacity in T/m2.

1.0 14.08 15.11

BH – 11

2.0 28.36 30.36

3.0 33.20 36.36

7. 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 17.84 28.54 53.51

4.0 23.54 37.67 70.63

Borehole- 11 5.0 27.19 43.50 81.57

6.5 29.71 47.53 89.12

8.0 31.58 50.53 94.75

9.0 36.49 58.38 109.47

10.0 46.31 74.10 138.94



8. 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.

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.

9. 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.

10. 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)



BORE LOG AND LAB TEST RESULT OF BOREHOLE



BORE HOLE - 11

Type of Soil Soil

Profile

Medium Plastic

0.00

Silty Clay CI

SC Poorly Graded Clayey Sand

Medium Plastic CI Silty Clay

Poorly Graded SP Sand

Depth SPT Value "N" Depth Plot

in mtrs.

0 10 20 30 40 5 0 6 0 70 80 90 1 00 0.0

1.0

2.0 26

WL:

3.0 2.60m

4.0 42

5.0 48

6.0

55

7.0

8.0 62

9.0 78

10.0 100

N Type of

Core R.Q.D

Recovery Sample (%)

(%)

N1 - N2 - N3

09-12-14 SPT Sample

15-19-23 SPT Sample

17-21-27 SPT Sample

20-26-29 SPT Sample

24-28-34 SPT Sample

32-37-41 SPT Sample

>100 SPT Sample



LIM

ITED

Sh

ear

Para

mete

rs

SOIL

SA

MP

LE

CLI

ENT:

AM

TZ

RL:

38m

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

72

88

83

.56

8

Gra

in s

ize

E:

LOC

AT

ION

: R

CC

STR

UC

TU

RE

CO

‐OR

DIN

ATE

S:‐

N:1

95

03

74

.27

3

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

D.S.F. 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

7

0.5

5

16

21

0.1

8

0.1

7

DS

DS

2.5

8

2.6

1

2.6

3

2.6

3

2.6

6

2.6

4

2.4

5

2.4

7

2.5

5

2.5

5

15.6

2

20.3

1

22.4

7

18.2

3

21.0

3

23.4

7

28.3

6

25.4

3

15.4

2

17.0

2

1.6

5

7

1.6

9

4

1

.99

4

2.0

0

3

CI S

C

SC

SC

SC

SC

CI

CI

SP

SP

14

10

12

12

11

10

18

16

NP

Np

21

19

20

21

19

22

24

22

NP

NP

29

35

32

33

30

3

2

42

38

22

21

30 20

20

15

20

15

40

35

0 0

53.7

4

34.0

9

43.4

7

37.5

1

38.5

3

32.6

6

64.7

4

59.5

0

3.6

3

4.3

1

30.2

4

9.8

4

14.8

8

9.6

5

10.4

5

7.8

9

9.8

8

24.1

6

65.3

5

51.2

4

12.3

4

35.0

2

26.9

7

18.9

7

31.2

0

13.6

4

20.1

4

12.4

7

31.0

2

42.5

6

3.6

8

21.0

5

14.6

8

33.8

7

16.7

7

40.1

2

5.2

4

3.8

7

0.0

0

1.8

9

0.0

0

0.0

0

0.0

0

0.0

0

3.0

5

5.6

9

0.0

0

0.0

0

0.0

0

0.0

0

-

- 26

- 42

48

55

62

78

10

0

DS

UD

S

SP

T

UD

S

SP

T

SP

T

SP

T

SP

T

SP

T

SP

T

00

. 1.0

2.0

3.0

4.0

5.0

6.5

08

.

9.0

10.0

No

.-1

0

B H



ALLOWABLE BEARING PRESSURE (ABP) AND

SAFE BEARING CAPACITY (SBC) OF SOIL



CALCULATION OF ALLOWABLE BEARING

PRESSURE (ABP) FOR SETTLEMENT

CRITERIA

Project Name: GEOTECHNICAL INVESTIGATION FOR AMTZ LTD.

Location: RCC STRUCTURE Project Code: 2017060007-GI

Bore Hole No.: 11 Water Table: 2.60 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 = 2.60 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 .

F i e l d S P T V a l u e ( 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

Fo xC orr

ecti

onf

orD

ept

has

per

IS:

80 09(

Par

t- I),F

ig-

12 C

Fi

nalC

orre

cted

Settl

emen

tinm

mS=

S

25A

BP

f

or

40A

BP

for

75A

BP

for

Correction of

- 9

Fi

g

i n

i n

i n

SPT values

IS:8

009(

Par

t-

I)

w

d

m m s e t t l e m e n t T / m

m m s e t t l e m e n t T / m

mm

settl

emen

tT/

m (IS:2131 -1981)

. . .

2

2

2

pe

r

/C

w

as r

x C

2

d

x C

i

2.00 26 2 26.00 20.50 12.48 0.65 0.73 14.01 17.84 28.54 53.51

4.00 42 2 42.00 28.50 8.56 0.50 0.62 10.62 23.54 37.67 70.63

5.00 48 2 48.00 31.50 7.66 0.50 0.60 9.19 27.19 43.50 81.57

6.50 55 2 51.15 33.10 7.26 0.50 0.58 8.42 29.71 47.53 89.12

8.00 62 2 52.70 33.90 7.07 0.50 0.56 7.92 31.58 50.53 94.75

9.00 78 2 62.40 38.70 6.12 0.50 0.56 6.85 36.49 58.38 109.47

10.00 100 2 80.00 47.50 4.91 0.50 0.55 5.40 46.31 74.10 138.94



CALCULATION OF SAFE BEARING CAPACITY (SBC) Based on C, • Value

Project Name: GEOTECHNICAL INVESTIGATION FOR AMTZ LIMITED

Location: RCC STRUCTURE Project Code: 2017060007 - GI

Bore hole no.: 11 Depth of Sample: 1.00 mtrs Water Table: 2.60 mtrs


Input Data

Kg/cm2

Cohesion C = 0.18 Depth of Foundation Df = 1.00 mtr.

Angle of internal friction Ф = 16 Degrees

tan-1 ( 0.67 tanФ ) Ф' = 11 Degrees Bulk Density = 1.994 gm/cc Field Moisture Content = 20.31 %

Dry Density γd = 1.657 gm/cc Specific Gravity Gs = 2.61 Saturated Density γsat = 2.025 gm/cc Void Ratio e = 0.57

Submersible Density γs = 1.025 gm/cc Width / Diameter of Footing (Assumed) B = 2 mtr.


Type of Footing = Square Footing

Condition of Soil = Medium

Overburden Pressure

Kg/cm2

Kg/cm2 q = (Df x γs) / 1000 = 0.103 Bγ =( B x γs) / 1000 = 0.205

IS:6403, Table -1 Bearing Capacity Factors

Ф Nc Nq Nγ Ф' N'c N'q N'γ

16 11.750 4.432 3.198 11 8.876 2.764 1.506

IS:6403, Table -2 Shape Factors For Square Footing Water Table Effect

Sc = 1.3 Sq = 1.2 Sγ = 0.8 W' = 0.5

Depth Factors Inclination Factors

dc = 1+0.2 x (Df/B) x tan(45+Ф/2) = 1.133 ic = iq = iγ = 1

dq = dγ = 1.066

Dense In case of general shear failure Net Ultimate Bearing Capacity

qd = CNcScdcic + q(Nq -1) Sqdqiq + 0.5 BγNγSγdγiγW'

= 3.115 + 0.450 + 0.140 = 3.705 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'

= 1.569 + 0.231 + 0.066 = 1.866 Kg/cm2

Medium After Interpolating, Net Ultimate Bearing Capacity Qnu = 3.521 Kg/cm2

Soil Bearing Capacity (SBC)= Qs = Qnu / FS + OB Factor of Safety (FS) = 2.5

Qs= 1.511 Kg/cm2 = 15.11 Tons/m2

Net Safe Bearing Capacity (NSBC)= Qns = Qnu / FS = Qs - OB

Qns= 1.408 Kg/cm2 = 14.08 Tons/m2

SBC = 15.11 Tons/m2 NSBC = 14.08 Tons/m

2



CALCULATION OF SAFE BEARING CAPACITY (SBC) Based on SPT "N" Value



Bore Hole No.: 11 Depth of Sample: 2.00 mtrs Water Table: 2.60 mtrs


Input Data Field SPT Value N = 26

Depth of Foundation Df = 2.00 mtr.

IS:2131, Fig-1 Corrected SPT value after over burden pressure N' = 33.800

Corrected SPT value after Dilatancy N" = 24.400

IS:6403, Fig-1 Angle of internal friction based on SPT "N" Value Ф = 33.9 Degrees

tan-1 ( 0.67 tanФ ) Ф' = 24 Degrees

Submersible density (Assumed) γs = 1.000 gm/cc Width / Diameter of Footing (Assumed) B = 2 mtr.



IS:6403, Fig-1 Condition of Soil = Medium

Overburden Pressure

Kg/cm2




34 39.728 27.340 37.778 24 19.542 9.808 9.782


Sc = 1.3 Sq = 1.2 Sγ = 0.8 W' = 0.5



dq = dγ = 1.188

Dense

In case of general shear failure Net Ultimate Bearing Capacity

C = 0

qd = CNcScdcic +

q(Nq -1) Sqdqiq +

0.5 BγNγSγdγiγW'

= 0.000 + 7.510 + 1.795 = 9.305 Kg/cm2



= 0.000 + 2.511 + 0.465 = 2.976 Kg/cm2



Qs= 3.036 Kg/cm2 = 30.36 Tons/m2


Qns= 2.836 Kg/cm2 = 28.36 Tons/m2


2



CALCULATION OF SAFE BEARING CAPACITY (SBC) Based on C, • Value



Bore hole no.: 11 Depth of Sample: 3.00 mtrs Water Table: 2.60 mtrs


Input Data

Kg/cm2

Cohesion C = 0.17 Depth of Foundation Df = 3.00 mtr.

Angle of internal friction Ф = 21 Degrees

tan-1 ( 0.67 tanФ ) Ф' = 14 Degrees Bulk Density = 2.003 gm/cc Field Moisture Content = 18.23 %

Dry Density γd = 1.694 gm/cc Specific Gravity Gs = 2.63 Saturated Density γsat = 2.052 gm/cc Void Ratio e = 0.55

Submersible Density γs = 1.052 gm/cc Width / Diameter of Footing (Assumed) B = 2 mtr.



Condition of Soil = Medium

Overburden Pressure

Kg/cm2




21 16.008 7.252 6.488 14 10.454 3.646 2.364


Sc = 1.3 Sq = 1.2 Sγ = 0.8 W' = 0.5



dq = dγ = 1.218

Dense In case of general shear failure Net Ultimate Bearing Capacity

qd = CNcScdcic + q(Nq -1) Sqdqiq + 0.5 BγNγSγdγiγW'

= 5.084 + 2.884 + 0.333 = 8.301 Kg/cm2



= 2.213 + 1.221 + 0.121 = 3.555 Kg/cm2



Qs= 3.636 Kg/cm2 = 36.36 Tons/m2


Qns= 3.320 Kg/cm2 = 33.20 Tons/m2


2



CHEMICAL TEST REPORTS:

WATER SAMPLES: (BH-11)

PARAMETERS UNIT RESULTS

pH Moles/H+ ions 6.81

CONDUCTIVITY s/cm 230

TDS ppm 115

CHLORIDE (CL) mg/ltr 17.99

HARDNESS (CaCo3) mg/ltr 64

TURBIDITY NTU 73.9

ALKALINITY mg/ltr 75

SOIL SAMPLES: (BH-11)

PARAMETERS UNIT RESULTS

pH Moles/H ions

6.32

CONDUCTIVITY s/cm 305.8

CHLORIDE mg/l 162

SULPHATE mg/l 117.3

TOTAL SOLUBLE SOLID mg/l 84.3



RECORD OF BORING FROM FIELD

(TO BE GIVEN LETER)


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GEOTECHNICAL INVESTIGATION REPORT - amtz.in · PDF file2017 geotechnical investigation report name of the project: geotechnical investigation studies work for andhrapradesh medtech