proposed construction of residential building (g+2...

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PROPOSED CONSTRUCTION OF RESIDENTIAL BUILDING (G+2

UPPER FLOORS) AT S.NO:156/1A1A1A2, 1ST CROSS STREET,

NEW BALAJI NAGAR, SELAIYUR, CHENNAI - 600 073.

Report on Geotechnical Investigation

Client: M/s. Alankar Construction,

No-12A, Bharathi Poonga Street,

Selaiyur , Tambaram,

Chennai-600 073.

MARS SYNERGY GEOTECH Pvt Ltd

An ISO 9001: 2015 Certificate Company

Plot #:206, 3rd Link Street, Nehru Nagar, Kottivakkam, OMR, (Kandanchavadi), Chennai-600 041.

Mail : [email protected], [email protected], Web: www.msgeotech.com

Project No: MSGTPL/SI-4001/18-19 Apr-2018

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Geo-Technical Investigation Report

Project No: MSGTPL/SI-4001/18-19 APr-2018.

0

Proposed Construction of Residential Building (G+2 Upper Floors) 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 BEARING CALCULATIONS.................................................................. 4

3.0 SITE PLAN –MSGTPL/SI-4001……………………………………………………. 5

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

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

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

7.0 SPECIFIC GRAVITY…………………………………………………………………. 12

8.0 GRAIN SIZE ANALYSIS…………………………………………………………….. 14

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REPORT ON SUBSOIL INVESTIGATION AND RECOMMENDATIONS FOR

SUITABLE TYPE OF FOUNDATION FOR THE PROPOSED CONSTRUCTION OF

RESIDENTIAL BUILDING (G+2) AT SELAIYUR.

1.0 INTRODUCTION

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

(G+2) at S.No:156/1A1A1A2, 1st Cross Street, New Balaji Nagar, Selaiyur, Chennai -

600 073, Tamil Nadu, INDIA. M/s. Mars Synergy Geotech Pvt Ltd, Chennai has

carried out this investigation and completed the field work on 3rd Apr 2018 as per

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 upper floors). 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 80tones for proposed building. These loads are assumed for

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

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• Mobilization 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

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-4001 enclosed. Investigations were

conducted 6.50m 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 four distinctive layers

there are

(i) Very loose to Medium Dense fine SAND up to -1.8m with SPT’s N=2-14

(ii) Very dense Moorum -1.80m to -2.50m with SPT’s N=>50

(iii) Soft Disintegrated Rock -2.5m to -3.5m with SPT’s N=>100

(iv) Fractured Hard Rock -3.50m to -6.50m with core recovery 10%

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

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1.6 GROUND WATER TABLE

At the time of soil investigation (03/04/2018), the ground water table was (-) 2.50m

encountered within the drilled depth.

1.6 DISCUSSION ON FOUNDATION

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

shallow depth onwards up to drilled depth -6.50m from existing ground level.

Based on soil strata it is ideal to adopt open shallow foundation at -1.8m level,

recommended.

1.8 RECOMMENDATIONS

The proposed structure is a G+2 upper floors residential building.

Excavate up to -1.80m, after excavation proper compaction to be done.

Adopt open shallow foundation in the form of isolated/strip raft at a depth of 1.8m below

the G.L

The Safe bearing capacity can be taken of soil at 1.8m below G.L can be taken as

25T/Sq.m.

Foundation should rest on 100mm thick 1:3:6 concrete mat.

Columns shall be tied in both directions at plinth level.

All foundation works should be done in dry conditions only.

Settlements are within permissible limits as per IS-1904-1986.

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2.0 DETERMINATION OF BEARING CAPACITY OF SHALLOW FOUNDATIONS [Based On IS: 6403-1981]

Size of Footing (1.5x1.5m) Calculation Purpose

Depth of Foundation: 1.8m

Existing Ground level: 0.00M

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

Bulk Density (W) of Soil above Footing Base: 1.80

Submerged Density (W') of Soil above Footing Base: 0.80T/Cu.M.

Bulk Density (W) of Soil Below Footing Base: 1.80T/Cu.M.

Factor of Safety 2.5

Shape factor Depth Factor Inclination Factor Sq = 1.200 Dq = 1.22 Iq = 1.000 Sg = 0.600 Dg = 1.22 Ig = 1.000 Water Table Correction Factor w’ = 0.50

Effective surcharge at base level q = 1.20 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): 320

Bearing Capacity Factors Nq = 24.36, Ng = 32.65

Thus Qult_n =65.38 T/Sq.M.

Allowable Bearing Capacity (Qall) =26.15T/Sq.M. Say 25T/m2

Settlement Calculations as per IS-8009-(Part1) 1998

S= Sc+Si Sc≈10mm

=0.01277x1000=12.77mm S= Sc+Si

S=10+12.77=22.77mm Say 23mm Total settlements 22mm, it is less than 25mm hence it is safe as per IS-1904-1986.

IEs

pBSi)1(

2µ−

=

mxSi 0102.031.13500

)3.01(5.132

2

=−

=

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Project No: MSGTPL/SI-4001/18-19

Project: Proposed Construction of Residential Building (G+2 Upper Floors) at Selaiyur

Location Selaiyur

Nil

Rotary Date of Start

Date of Complete

Dia of Bore (mm) 100 Sheet

Termination Depth (m) 6.5m 1 of 1

De

pth

be

low

EG

L (

m)

La

ye

r T

hic

kn

ess

Soil Layers Description

So

il S

ym

bo

l

IS-C

lassific

atio

n

Typ

e F

ield

Te

st

Te

st D

ep

th (

m)

SP

T-

N-

Va

lue

0.0

0.5

1.0 SPT 1.0 3 5 9 14

1.5

2.0 SPT 2.0 17 21 33 54

2.5

3.0 SPT 3.0

Very Dense Brownish

Moorum

50 Blows for 3CmSoft Disintegrated Rock G

P

Drilling

Medium Dense Brownish

Clayey SAND SC

SM

1.0

1.0

1.0

BOREHOLE LOG

Ground R.L (-) 2.5m

3-Apr-2018

SPT Values Record

0 to 45cm

Graphical Representation of SPT

3-Apr-2018

Borehole No BH-1

G.W.T (m)

0 10

20

30

40

50

60

70

80

90

10

0


3.0 SPT 3.0

3.5

4.0 SPT 4.0 - - - >100

4.5

5.0 SPT 5.0

5.5

6.0

6.5 SPT 6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

EGL- Existing Ground Level SPT- DS-

R.L- Reduced Level UDS- CR-

Ground Water Table VST- RQD- Rock Quality Designation

CR=10%

50 Blows for 3Cm

CR=5%

Ve

ry P

oo

r

Fractured Hard Rock

Borehole Termination Depth (m) 6.5m

GWT-

Disturbed SampleStandard Penetration Test

Undisturbed Sample

Vane Shear Test

Core Recovery

3.5

6

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Project: Proposed Construction of Residential Building (G+2 Upper Floors) at Selaiyur

Location Selaiyur

Nil

Rotary Date of Start

Date of Complete

Dia of Bore (mm) 100 Sheet

Termination Depth (m) 6.5m 1 of 1

De

pth

be

low

EG

L (

m)

La

ye

r T

hic

kn

ess

Soil Layers Description

So

il S

ym

bo

l

IS-C

lassific

atio

n

Typ

e F

ield

Te

st

Te

st D

ep

th (

m)

SP

T-

N-

Va

lue

0.0

0.5

1.0 SPT 1.0 1 1 1 2

1.5

2.0 SPT 2.0 9 22

2.5

3.0 SPT 3.0

50 Blows for 9Cm

GP

SM

Soft Disintegrated Rock

Very Dense Brownish

Moorum

1.0

1.0

1.0Very Loose Brownish Silty

Fine SAND SM

50 Blows for 0Cm

Drilling 3-Apr-2018

3-Apr-2018

SPT Values Record

0 to 45cm


Ground R.L G.W.T (m) (-) 2.5m

BOREHOLE LOG

Borehole No BH-2

0 10

20

30

40

50

60

70

80

90

10

0


3.0 SPT 3.0

3.5

4.0 SPT 4.0 - - - >100

4.5

5.0 SPT 5.0 - - - >100

5.5

6.0

6.5 SPT 6.5 - - - >100

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

EGL- Existing Ground Level SPT- DS-

R.L- Reduced Level UDS- CR-

Ground Water Table VST- RQD- Rock Quality DesignationGWT- Vane Shear Test

Borehole Termination Depth (m)

Ve

ry P

oo

r

3.5

6.5m

Standard Penetration Test Disturbed Sample

Undisturbed Sample Core Recovery

50 Blows for 0Cm

Fractured Hard Rock

7

FINAL COPY5.0 TEST RESULTS


NM

C

WL

WP

I P Ic

Fre

eS

well

Gra

vel

Co

ars

e S

an

d

Med

ium

San

d

Fin

e S

an

d

Sil

t &

Cla

y

0.00

14 1.00 15 2.63 3 5 31 25 36

54 2.00 11 2.61 11 6 23 36 24

>100 3.00

>100 4.00

Rock 5.00

Rock 6.50

Very

poor

3.50 Fractured Hard Rock

Very Dense Brownish Moorum1.00

Soft Disintegrated Rock GP1.00

Grain Size Analysis (%)Index Properties (%)

Project : Proposed Construction of Residential Building (G+2 Upper Floors) at Selaiyur

BH No 1

SUMMARY OF TEST RESULTS

6.5mTermination Depth: Ground Water Level:(-)2.50m

N' V

alu

e

Layer

Th

ickn

ess

Dep

th (

m)

So

il D

escri

pti

on

IS C

lassif

icati

on

SCMedium Dense Brownish Clayey

SAND1.00

SM

Sp

ecif

ic G

ravit

y

8

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NM

C

WL

WP

I P Ic

Fre

eS

well

Gra

vel

Co

ars

e S

an

d

Med

ium

San

d

Fin

e S

an

d

Sil

t &

Cla

y

0.00

2 1.00 14 2.61 5 2 23 38 32

>100 2.00 12 2.63 9 6 29 30 25

>100 3.00

Rock 4.00

Rock 5.00

Rock 6.50

Very

Poor

3.50 Fractured Hard Rock

1.00Very Loose Brownish Silty Fine

SAND SM

SMVery Dense Brownish Moorum1.00

1.00 GPSoft Disintegrated Rock

SUMMARY OF TEST RESULTS

N' V

alu

e

Layer

Th

ickn

ess

Dep

th (

m)

So

il D

escri

pti

on

IS C

lassif

icati

on Index Properties (%)

Sp

ecif

ic G

ravit

y

Grain Size Analysis (%)


BH No 2 Ground Water Level:(-)2.50m Termination Depth: 6.5m

9

FINAL COPY6.0 NATURAL MOISTURE CONTENT



Method: IS-2720 P-2

BH.No/ Pit no

Depth (m)

Tare No 113 136 143 104 244 209 23 169

Wt of Tare (gr) 29.49 29.56 29.53 29.86 29.97 29.26 31.06 30.87

Tare + Soil (gr) 49.79 65.96 66.71 55.11 57.42 61.80 60.56 60.50

Tare+Dry soil (gr) 47.15 61.16 63.12 52.65 54.12 57.78 57.42 57.29

Wt of Water (gr) 2.64 4.80 3.59 2.46 3.30 4.02 3.14 3.21

Wt Dry soil (gr) 17.66 31.60 33.59 22.79 24.15 28.52 26.36 26.42

Water Content (%) 14.95 15.19 10.69 10.79 13.66 14.10 11.91 12.15

Average Water

Content (%)

Natural Moisture Content Data Sheet

1.0

1 1 2 2

15 11 14

1.02.0

12

2.0

11

FINAL COPY7.0 SPECIFIC GRAVITY


BH.No 1 BH.No 1

Depth(m) 1.0 Depth(m) 2.0

Pycnometer number 18 82 Pycnometer number 9 61

Weight of bottle w1 g 35.9000 33.2900 Weight of bottle w1 g 34.0800 34.5400

Weight of bottle + soil w2 g 46.7400 47.1600 Weight of bottle + soil w2 g 49.1000 49.5600

Weight of bottle + soil + water w3 g 95.1200 94.8200 Weight of bottle + soil + water w3 g 96.3100 95.4600

Weight of bottle full of water w4 g 88.4000 86.2200 Weight of bottle full of water w4 g 87.0400 86.1900

w2-w1 g 10.8400 13.8700 w2-w1 g 15.0200 15.0200

w2-w1

(w4-w1)-(w3-w2)2.63107 2.63188

w2-w1

(w4-w1)-(w3-w2)2.61217 2.61217

2.63 2.61

SPECIFIC GRAVITY TEST


Specific gravity

Weight of soil

Average value Gs Average value Gs

Weight of soil

Specific gravity

12

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BH.No 2 BH.No 2

Depth(m) 1.0 Depth(m) 2.0

Pycnometer number 60 62 Pycnometer number 63 2

Weight of bottle w1 g 33.9700 34.2000 Weight of bottle w1 g 33.0400 35.9800

Weight of bottle + soil w2 g 50.4600 53.9900 Weight of bottle + soil w2 g 48.5100 50.7500

Weight of bottle + soil + water w3 g 96.4200 98.5300 Weight of bottle + soil + water w3 g 95.0400 96.6400

Weight of bottle full of water w4 g 86.2500 86.3400 Weight of bottle full of water w4 g 85.4500 87.4800

w2-w1 g 16.4900 19.7900 w2-w1 g 15.4700 14.7700

w2-w1

(w4-w1)-(w3-w2)2.60918 2.60395

w2-w1

(w4-w1)-(w3-w2)2.63095 2.63280

2.61 2.63Average value Gs Average value Gs

SPECIFIC GRAVITY TEST


Weight of soil Weight of soil

Specific gravity Specific gravity

13

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8.0 GRAIN SIZE ANALYSIS

GRAIN SIZE ANALYSIS



SILT

4.7520.4250.0750.0020

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1

Pe

rce

nta

ge

Fin

er

(%)

Particle Size (mm)

BH 1 Depth 1.0m

BH 1 Depth 2.0m

SANDSAND

CLAY SILT

FINE MEDIUM COARSE

Depth Gravel

(m) (%) Coarse Medium Fine

1 1.0m 3 5 31 25 0.000 0.156

1 2.0m 11 6 23 36 0.156 0.449

2 1.0m 5 2 23 38 0.156 -0.056 -0.4

2 2.0m 9 6 29 30 0.449 0.150 0.682 1.5 0.1

SAND (%)BH-No

25

32

24

36

SILT& CLAY

(%)

D60

(mm)

D30

(mm)

D10

(mm)CcCu

4.7520.4250.0750.0020

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1

Pe

rce

nta

ge

Fin

er

(%)

Particle Size (mm)

2 Depth 1.0m

BH 2 Depth 2.0m

SAND

FINE MEDIUMCLAY

COARSESILT

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proposed construction of residential building (g+2...

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