proposed construction of g+2 … investigation report project no: msgtpl/si-3597/16-17 nov-2016. 1...

PROPOSED CONSTRUCTION OF G+2 RESIDENTIAL BUILDING

AT NO:26, BAJANAI KOIL STREET, BHARATHI NAGAR,

SELAIYUR, CHENNAI.

Report on Geotechnical Investigation

Client:

M/s. Alankar Construction,

Chennai.

MARS SYNERGY GEO TECH Pvt Ltd

An ISO 9001: 2015 Certificate Company # 30/25 Drowpathy Amman Koil 1

st Street

Velachery, Chennai-600 042.

Ph : (044) –22452845, Tele Fax: 2245 0281 Mail : [email protected], [email protected],

Web: www.msgeotech.com

Project No: MSGTPL/SI-3597/16-17 Nov-2016.

Geo-Technical Investigation Report


Proposed Construction of G+2 Residential Building at Selaiyur

TABLE OF CONTENTS

1.0 INTRODUCTION……………………………………………………………………. 1

1.1 DESCRIPTION OF STRUCTURE………………………………………………… 1

1.2 SOIL INVESTIGATION PROGRAMME …………………………………………. 1

1.3 FIELD SAMPLING……………………………………………….………………… 2

1.4 LABORATORY TESTS…………………………………………………………… 2

1.5 SOIL PROFILE………………………………………………………………………. 2

1.6 GROUND WATER TABLE……………………………………………………….. 3

1.7 DISCUSSION ON FOUNDATION…………………………………………………. 3

1.8 RECOMMENDATIONS……………………………………………………………. 3

2.0 SAFE BEARINGCAPACITY CALCULATIONS.............................................. 4

3.0 SITE PLAN –MSGTPL/SI-3597……………………………………………………. 5

4.0 BORE-LOGS………………………………………………………………………… . 6

5.0 TEST RESULTS…………………………………………………………………….. 8

6.0 NATURAL MOISTURE CONTENT……………………………………………….. 10

7.0 SPECIFIC GRAVITY…………………………………………………………………. 11

8.0 GRAIN SIZE ANALYSIS…………………………………………………………….. 12



1


REPORT ON SOIL INVESTIGATION AND RECOMMENDATIONS FOR THE

FOUNDATIONS OF THE PROPOSED CONSTRUCTION OF RESIDENTIAL

BUILDING (G+2) AT SELAIYUR, CHENNAI,

1.0 INTRODUCTION

M/s. Alankar Construction, Chennai are planning to construct the residential building

(G+2) at No:26, Bajanai Koil Street, Bharathi Nagar, Selaiyur, Chennai-600 073,

Tamilnadu, INDIA. M/s. Mars Synergy Geotech Pvt Ltd, Chennai has carried out this

investigation and completed the field work on 08th Nov 2016 according to the instructions

from the owner of the project.

The scope of work includes the following:

� Making two numbers of Standard Soil Investigation bore-holes

� Collecting soil samples at regular depth intervals

� Conducting SPTs at every 1.0m/1.50m depth intervals

� Conducting laboratory tests on samples collected

� Submitting report with laboratory test results and recommendations for

foundations.

1.1 DESCRIPTION OF STRUCTURE

The proposed structure is residential building (G+2). The exact details of columns are

not available at the time of preparation of this report. Assuming an approximate column

spacing of 4 to 5 m c/c considering this the central column load works about 60 to 70

tones for proposed building. These loads are assumed for the purpose of foundation

only and for the structural design, exact loads are to be estimated based on a suitable

structural analysis.

1.2 SOIL INVESTIGATION

The field investigation works were carried out using 1 set of Rotary mechanical drilling

Rig. The following activities, carried out in chronological sequence, comprised the

fieldwork for the project

• Mobilisation of rotary drill rig, water pump, testing tools and accessories.

• Collection of disturbed samples of non-cohesive soils.

• Sampling and logging of the boreholes. Packing, labeling and dispatching the

samples to laboratory.

• Field investigation, tests and laboratory tests conducted as per IS-1892 and IS -2720



2


1.3 FIELD SAMPLING

Two numbers of standard soil investigation boreholes of 100mm diameter was made at

the locations shown in the figure, MSGTPL/SI-3597 enclosed. Investigations were

conducted up to 5.50 from existing ground level where SPT is more than 50blows. SPTs

were conducted at every 1.0m/1.5m depth intervals and samples were collected for

identification and testing.

1.4 LABORATORY TESTS

The laboratory-testing scheme is so designed to obtain the design parameters for the

foundations. The following parameters are evaluated:

� Type of soil and it's gradation properties

� Specific Gravity

� Natural Moisture Content (NMC)

� Sieve analysis on the coarse grained soil fraction

All the test results are presented in the tabular forms. Comprehensive field information

along with SPT values is presented on separate sheet.

1.5 SOIL PROFILE

Based on visual identification of soil samples and test results (of both field and

laboratory tests), the soil profile arrived. Subsoil is made-up of three distinctive layers

there are

(i) Medium Dense clayey SAND up to -1.50m with SPT’s N=25

(ii) Very Dense moorum -1.50m to -3.50m with SPT’s N=>50

(iii) Soft disintegrated Rock -3.50m to -5.0m with SPT’s N=>100

The soil profile details are presented in the bore-chart.

1.6 GROUND WATER TABLE

At the time of soil investigation (08/11/2016), the ground water table was not

encountered within the site location. However Ground water table in recorded from

nearby open well at (-) 4.0m from existing ground level.



3


1.7 DISCUSSION ON FOUNDATION

From the sub soil profile and laboratory test data, it can be seen that the soil is medium

dense SAND up to -1.50m followed by very dense moorum up to -3.50m, below this

layer 1.50m thick soft disintegrated rock layer is encountered up to -5.0m from existing

ground level.

Based on soil strata it is ideal to adopt open shallow foundation at -1.50m level,

recommended.

1.8 RECOMMENDATIONS

� Open shallow in the form of isolated column footings/Strip Raft located at a

depth of -1.50m below the existing G.L

� The Safe bearing capacity can be taken of soil at 1.50m below G.L can be taken

as 20T/sq.m., Similarly SBC at 2.0m depth 25T/sq.m can be adopted.

� These footing should rest on 100mm thick of 1:3:6 mat.

� Columns shall be tied in both directions at plinth level.

� All foundation works should be done in dry conditions only.

Note: This recommendation has been given on the assumed loads. The structural engineer

can modify it based on structural analysis on actual size of the building and column details.



4


2.0 DETERMINATION OF BEARING CAPACITY OF SHALLOW FOUNDATIONS

[Based On IS: 6403-1981]

Footing Size =1.5mx1.5m (Assumed for calculation) Depth of Foundation: 1.50m

Existing Ground level: 0.00M

Ground Water Table level: -0.00M (Due to Heavy Rain Temporary)

Bulk Density (W) of Soil above Footing Base: 1.85

Submerged Density (W') of Soil above Footing Base: 0.85T/Cu.M.

Bulk Density (W) of Soil below Footing Base: 1.85

Shape factor Depth Factor Inclination Factor Sq = 1.00 Dq = 1.17 Iq = 1.000 Sg = 0.80 Dg = 1.17 Ig = 1.000 Water Table Correction Factor w’ = 0.50

Effective surcharge at base level q = 1.275 T/Sq.M.

Ultimate Net B.C. = Qult_n = q*(Nq-1)*Sq*Dq*Iq + 0.5*B*W*Ng*Sg*Dg*Ig*W'

Angle of Internal Friction (phai): 31

Bearing Capacity Factors Nq = 21.38, Ng = 27.53

Thus Qult_n =50.32T/Sq.M. Allowable Bearing Capacity (Qall) = 20.13T/Sq.M. Say 20T/m2

Settlement Calculations as per IS-8009-(Part1) 1998 S= Sc+Si

Sc=5mm

=0.0143x1000=14.30mm S= Sc+Si

S=5+14.30=19.30mm Say=20mm

Total settlements 20.0 mm, It is less than 25mm hence it is safe as per IS 1904-1986.

IEs

pBSi)1(

2µ−

=

mxSi 0143.013.12500

)3.01(5.120

2

=−

=

4.0 BORE-LOGS

Bore Hole No.

Type of Boring

Started on

Ended on

Dep

th (

m)

15 30 45 N

0.0 0.00

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

4.00

65 8722

-

Graphical Representation of SPT

13

25

Type o

f S

am

ple

s

Depth

(m

)

5.00

SP

T

Layer

Thic

kness

Soil Description

2.00

1.00

SPT Details

IS C

lassific

ation

Soil

Pro

file

s

11

Project No: MSGTPL/SI-3597/16-17

Project : Proposed Construction of G+2 Residential Building at Selaiyur

:1

Dia of Boring

:NilG.W.L

:100mm

: Ref. Fig

: 5.0m

Location

Soil Drilled

3.00

:Rotary

:08/11/2016

:08/11/2016

SP

TS

PT

SP

TS

PT

148

- -

>100---

50 Blows for 10cm

>100

2.50

2.00

1.00

GP

GP

SCMedium Dense Brownish

Clayey SAND

Brownish Moorum

Soft Disintegrated Rock

0 10

20

30

40

50

70

60

80

90 10

0

7.5

8.0

8.5

9.0

9.5

10.0

Soil Profile BH-1 Location

Borehole Terminated at 5.0m Below Ground Level.

6

Bore Hole No.

Type of Boring

Started on

Ended on

Dep

th (

m)

15 30 45 N

0.0 0.00

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

52

>100-

SC

--3.50

15

: Ref. Fig

: 3.5m

Location

Soil Drilled

SP

TS

PT

SP

T

SPT Details

IS C

lassific

ation

Soil

Pro

file

s

40

Very Dense Brownish Clayey

SAND

:Rotary

:08/11/2016

:08/11/2016



:2

Dia of Boring

:NilG.W.L

:100mm

Graphical Representation of SPT

-

92

Type o

f S

am

ple

s

Depth

(m

)

2.00

1.00

Layer

Thic

kness

Soil Description

1.00

- >100-

Soft Diisntegrtaed Rock GP

2.50

0 10

20

30

40

50

70

60

80

90 10

0

7.5

8.0

8.5

9.0

9.5

10.0

Borehole Terminated at 3.5m Below Ground Level.

Soil Profile BH-2 Location

7

5.0 TEST RESULTS


NM

C

WL

WP

I P Ic

Fre

eS

we

ll

Gra

ve

l

Co

ars

e S

an

d

Me

diu

m S

an

d

Fin

e S

an

d

Sil

t &

Cla

y

0.00

25 1.00 14 2.67 7 5 25 24 39

87 2.00 7 2.68 12 9 27 24 28

>100 3.00 7 2.67 43 8 18 17 14

>100 4.00

>100 5.00

2.00

Medium Dense Brownish

Clayey SAND

Brownish Moorum

IS C

las

sif

ica

tio

n

GP

GP

SC

SUMMARY OF TEST RESULTS

La

ye

r T

hic

kn

es

s

Grain Size Analysis (%)

Soft Disintegrated Rock

1.00

2.00

Sp

ec

ific

Gra

vit

y


So

il D

es

cri

pti

on

De

pth

(m

)

N' V

alu

e

1BH No Termination Depth: -: 5.0mGround Water Level:Nil

Index Properties (%)

8


NM

C

WL

WP

I P Ic

Fre

eS

we

ll

Gra

ve

l

Co

ars

e S

an

d

Me

diu

m S

an

d

Fin

e S

an

d

Sil

t &

Cla

y

0.00

92 1.00 8 2.68 1 2 32 32 33

>100 2.00

>100 3.50

Termination Depth: -: 3.5mGround Water Level:Nil

Index Properties (%)

IS C

las

sif

ica

tio

n

Very Dense Brownish

Clayey SAND

2.50

1.00 SC

GPSoft Diisntegrtaed Rock

SUMMARY OF TEST RESULTS

La

ye

r T

hic

kn

es

s

Grain Size Analysis (%)

Sp

ec

ific

Gra

vit

y


So

il D

es

cri

pti

on

De

pth

(m

)

N' V

alu

e

1BH No

9

6.0 NATURAL MOISTURE CONTENT



Method: IS-2720 P-2

BH.No/ Pit no

Natural Moisture Content Data Sheet

1 1 1 2BH.No/ Pit no

Depth (m)

Tare No 13 2 164 8 219 24 65 237

Wt of Tare (gr) 29.80 28.36 30.61 29.23 31.53 31.35 28.45 29.10

Tare + Soil (gr) 58.77 55.36 65.37 66.97 50.86 53.48 56.44 54.99

Tare+Dry soil (gr) 55.12 51.93 63.00 64.31 49.52 51.96 54.49 53.00

Wt of Water (gr) 3.65 3.43 2.37 2.66 1.34 1.52 1.95 1.99

Wt Dry soil (gr) 25.32 23.57 32.39 35.08 17.99 20.61 26.04 23.90

Water Content (%) 14.42 14.55 7.32 7.58 7.45 7.38 7.49 8.33

Average Water

Content (%) 8

1.0

14 7 7

3.02.01.0

1 1 1 2

10

7.0 SPECIFIC GRAVITY


BH.No 1 BH.No 1

Depth(m) 1.0 Depth(m) 2.0

Pycnometer number 46 43 Pycnometer number 71 72

Weight of bottle w1 g 32.7700 32.2300 Weight of bottle w1 g 36.2900 34.0700

Weight of bottle + soil w2 g 54.4200 54.2200 Weight of bottle + soil w2 g 59.2500 56.5000

Weight of bottle + soil + water w3 g 101.3500 101.2500 Weight of bottle + soil + water w3 g 101.9700 99.9000

Weight of bottle full of water w4 g 87.8300 87.4900 Weight of bottle full of water w4 g 87.5500 85.8700

w2-w1 g 21.6500 21.9900 w2-w1 g 22.9600 22.4300

w2-w1

(w4-w1)-(w3-w2)2.66298 2.67193

w2-w1

(w4-w1)-(w3-w2)2.68852 2.67024

2.67 2.68


Specific gravity

Weight of soil

SPECIFIC GRAVITY TEST

Average value Gs Average value Gs

Weight of soil

Specific gravity

11


BH.No 1 BH.No 2

Depth(m) 3.0 Depth(m) 1.0

Pycnometer number 19 25 Pycnometer number 32 38

Weight of bottle w1 g 34.6800 38.0800 Weight of bottle w1 g 46.3100 40.6400

Weight of bottle + soil w2 g 53.2400 55.6300 Weight of bottle + soil w2 g 68.1100 61.9100

Weight of bottle + soil + water w3 g 93.6700 92.8500 Weight of bottle + soil + water w3 g 110.5000 107.6600

Weight of bottle full of water w4 g 82.0700 81.8600 Weight of bottle full of water w4 g 96.8300 94.3200

w2-w1 g 18.5600 17.5500 w2-w1 g 21.8000 21.2700

w2-w1

(w4-w1)-(w3-w2)2.66667 2.67530

w2-w1

(w4-w1)-(w3-w2)2.68143 2.68222

2.67 2.68

SPECIFIC GRAVITY TEST

Average value Gs Average value Gs

Weight of soil

Specific gravity


Specific gravity

Weight of soil

12

8.0 GRAIN SIZE ANALYSIS

BH 1

Depth

% Soil

retained

Cumulative %

FinerAverage Sieve

PSR % F % size (mm)(1) (2) (3)

6.74 93.27 4.750

5.28 87.99 3.375

15.28 72.71 1.500

5.10 67.61 0.800

4.86 62.75 0.513

8.23 54.53 0.319

7.23 47.30 0.181

8.33 38.97 0.113

Average Particle Diameter = 0.8767

BH 1

Depth

% Soil

retained

Cumulative %

FinerAverage Sieve

PSR % F % size (mm)(1) (2) (3)

12.30 87.70 4.750

8.89 78.81 3.375

16.52 62.30 1.500

4.81 57.49 0.800

5.37 52.12 0.513

8.99 43.13 0.319

5.45 37.68 0.181

9.21 28.47 0.113

1.2987

Gravel

Fine Medium Coarse Fine Medium Coarse Fine

% Particle Size 2.0 %

7 Gravel 12

5 Coarse Sand 9

25 0.757 Medium Sand 27

24 Fine Sand 24

39 Silt & Clay 28

Silt

0.212

0.150

9

8

8

9

2.0m

2

1

1.0m

S.No.

2.000

Clay

Average Particle Diameter =

0.600

passing 0.075

0.425

7

6

5

4

S.No.

6

7

Sieve Analysis Test

1

2

3

Product of

Columns(1) x (3)31.99

24.77

4

5

Sieve Aperture size used

(mm)

4.750

3

Sand

124.679

0.99

1.04

2.75

2.86

2.000

17.82

22.92

4.08

2.62

1.31

0.94

Product of

84.163

(1) x (3)

0.150

0.075

4.750

passing 0.075


(mm)

3.85

1.000

58.43

30.00

Medium Sand

Fine Sand

0.075

0.087

0.809

Particle Size

Silt & Clay



Gravel

Coarse Sand

1.0

1.000

0.600

0.425

0.212

2.49

0

10

20

30

40

50

60

70

80

90

100

0.001 0.010 0.100 1.000 10.000

Particle size [mm]I Depth II Depth

Cum

ula

tive

P

erc

enta

ge F

iner

D10 =D30 =D60 =

D10 =D30 =D60 =

Depth = Depth =

Cu =

Cc =

Cu =

Cc =

13

BH 1

Depth

% Soil

retained

Cumulative %

FinerAverage Sieve

PSR % F % size (mm)(1) (2) (3)

42.89 57.11 4.750

7.89 49.22 3.375

9.51 39.71 1.500

3.66 36.05 0.800

4.99 31.06 0.513

7.45 23.61 0.319

3.18 20.43 0.181

6.84 13.59 0.113

Average Particle Diameter = 2.6440

BH 2

Depth

% Soil

retained

Cumulative %

FinerAverage Sieve

PSR % F % size (mm)(1) (2) (3)

1.00 99.00 4.750

2.39 96.61 3.375

17.42 79.19 1.500

7.59 71.60 0.800

7.35 64.25 0.513

15.67 48.58 0.319

8.51 40.07 0.181

7.95 32.12 0.113

0.5856

Gravel

Fine Medium Coarse Fine Medium Coarse Fine

% Particle Size 1.0 %

43 Gravel 1

8 0.395 Coarse Sand 2

18 8.610 Medium Sand 32

17 Fine Sand 32

14 Silt & Clay 33

2.56

Silt & Clay



Gravel

Coarse Sand

3.0

1.000

0.600

0.425

0.212

8.08

Medium Sand

Fine Sand

0.075

0.367

Particle Size

253.825

0.150

0.075

4.750

passing 0.075


(mm)

6.07

1.000

4.75

Sand

56.220

1.54

0.89

2.000

26.63

14.27

2.93

2.37

0.58

3.77

4.99

(1) x (3)

Product of

Columns(1) x (3)203.73

26.13

0.77

Product of

4

5

5

4

S.No.

6

7

Sieve Analysis Test

1

2

3


(mm)

4.750

3.0m

S.No.

2.000

Clay

Average Particle Diameter =

0.600

passing 0.075

0.425

7

6

Silt

0.212

0.150

9

8

8

9

1.0m

2

1

3

0

10

20

30

40

50

60

70

80

90

100

0.001 0.010 0.100 1.000 10.000

Particle size [mm]I Depth II Depth

Cum

ula

tive

P

erc

enta

ge F

iner

D10 =D30 =D60 =

D10 =D30 =D60 =

Depth = Depth =

Cu =

Cc =

Cu =

Cc =

14

proposed construction of g+2 … investigation report project no: msgtpl/si-3597/16-17 nov-2016. 1...

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