soil investigation at sinaran drive · soil investigation at sinaran drive ... 2.3 laboratory tests...
TRANSCRIPT
Soil Investigation at
Sinaran Drive
For M/s Urban Redevelopment Authority
Purchase Order No. URA000EPO05000681 Issue Date : 19-07-2005
Date: 12th August, 2005
Company Registration No: 198403839N
TABLE OF CONTENT Page
1.0 INTRODUCTION 1
2.0 SCOPE OF WORK 2
2.1 Site Condition 2
2.2 Field Investigation 2
2.2.1 Driling 2
2.2.2 Standard Penetration Test 2
2.2.3 Undisturbed Sampling 3
2.3 Laboratory Tests 4
2.3.1 Moisture Content 4
2.3.2 Bulk and Dry Density Determination Tests 4
2.3.3 Unconsolidated Undrained Triaxial Compression Test 5
3.0 RESULT OF SOIL INVESTIGATION 5
3.1. Subsoil Condition 5
3.2. Laboratory Tests 7
APPENDICES
A. TABLES & CHARTS
o Table 1. Summary on Quantity of Field Investigation
o Table 2. Monitoring Record for Water Level at Borehole (During Operation)
B. LOCATION PLAN
o Map Showing Location of Project
o Map Showing Location of Boreholes
C. BOREHOLE LOG
o Key to Boring Log
o Bore Hole Log
o Generalized Soil Profile (Cross-Sections)
D LABORATORY TEST RESULTS
o Summary of Test Results
o Test Results
The contents as described in this report for
Soil Investigation at Sinaran Drive
are hereby certified to be correct
…………..…………
Endorsed by P.E.
1
1.0 INTRODUCTION
1.1 General
This report presents the soil investigation based on 4 boreholes, conducted at
the project site, (See location map in APPENDIX - B). The main purpose of the soil
investigation is to obtain and understand the geotechnical information on the subsoil
conditions required for the design and construction works.
a) Name of the Project : Project Site at Sinaran Drive
b) Location : Near Novena MRT Station
c) Client : Urban Redevelopment Authority
d) Period of Work : Field Work
22 July - 1 August, 2005 e) Scope of Work : Field Work
Number of Borehole 4 nos.
Drilling in soil 138.52 m.
Standard Penetration Test (SPT) 45 nos
Undisturbed Sample (UD) 12 nos.
Disturbed Sample (DS) 29 nos.
2
2.0 SCOPE OF WORK
2.1 Site Condition
The project site is located near Novena MRT station, at the corner of Sinaran
Drive and Moulmein Road. The ground surface at this site behaves a gentle slope
towards the road side. The key plan of the project site, including location of the
boreholes, is shown in APPENDIX - B.
2.2 Field Investigation
The field work involved in the geotechnical investigation was carried out as
recommended in BS 5930: 1981 “Code of Practice for Soil Investigation”. Prior to
commencement of the site investigation, trial pit up to 2.0m in depth was conducted at
each borehole before drilling. Summary on quantity of field works for this project is
listed in APPENDIX – A (Table 1).
2.2.1 Drilling
Drilling was carried out using hydraulic feed rotary boring machine. A metal
crown bit as a cutting tool was attached at the lower end of the drilling rods and
circulated mud water was pumped through hollow rods into the bottom of borehole to
wash out the cuttings to ground surface.
4 nos. of boreholes were performed at 4 points namely, BH-1 to BH-4. All
boreholes were terminated when drilling encountered underlying rock and showed
rebounding effect on the drill stem, or as per instruction from the client representatives.
The diameter of the borehole is 100mm. The boring log data is summarized in
APPENDIX - C. In this project, total drilling depth is 138.52 m. 2.2.2. Standard Penetration Test
This test is done in accordance with BS 1377: 1990 Part 9 and covers the
determination of the resistance of the penetration of a split-barrel sampler and
obtaining disturbed samples of the soil for identification purpose.
3
It was performed using a split-barrel sampler connected to the lower end of
boring rods. The sampler was driven into soil by means of a 63.5kg hammer falling
freely through a height of 76cm onto an anvil attached to the top of the rods. A trip-
release mechanism and guiding assembly were used to control the falling hammer and
the driving energy was thus transmitted through the rods to the SPT sampler. The
sampler was driven 45cm into soil with the number of blows required for each 15cm
of penetration recorded. The resistance, N-value, was taken as the number of blows
for the last 30cm of penetration.
When 100 blows were reached before the full penetration of 30cm, no further
blows were applied and the final penetration was recorded. At the end of the test, the
sampler was withdrawn and some extracted soil was placed into a plastic container
and then labeled. These samples were used to describe the type of soil existing in the
boring points.
In this project, total 45 numbers of SPT were taken in order to get the
information and technical data on the strength and type of soil (See Table 1).
2.2.3 Undisturbed Sampling
Undisturbed sampling was carried out by using a thin-wall tube sampler with
outer diameter of 75mm. Prior to sampling; the borehole was flushed with water to
remove the remnants left at the bottom of the borehole. The bottom was measured to
confirm the depth at which the soil sample was taken. The sample tube was lowered
down to the bottom of the hole and jacked into soil. After the sample tube was jacked
to the required depth, the sample tube was taken out to the surface. Wax was then
applied to form a seal on both sides of the UD tube and labelled properly before
transporting to the laboratory for testing.
In this project, total 12 numbers of undisturbed samples were collected by
taking UD samples at the depth of 3, 6 & 9 meters from each borehole whenever the
conditions are favourable. (See Table 1).
4
2.3 Laboratory Tests
The following Laboratory tests are carried out on the undisturbed samples
obtained from the boreholes. Summary of test results are listed in APPENDIX - D.
- Moisture Content
- Bulk and Dry Density Determination Tests
- Unconsolidated Undrained Triaxial Compression Test
The purpose of laboratory tests is for the evaluation of shear strength,
compressibility characteristics and classification of soil properties. All tests were
carried out in accordance to BS 1377. Classification of soil types is based on the
Unified Soil Classification System (USCS).
2.3.1. Moisture Content
To determine the moisture content of soils, a soil sample is dried at a
temperature of 105°C to 110°C for about 24 hours. The loss in weight of the soil
sample represents the weight of moisture in the soil. The moisture content of the soil
to the dry weight of soil in percentage is the moisture content of the testing soil. This
test if performed in accordance with BS 1377 : Part 2 : 1990 #3.
2.3.2. Bulk and Dry Density Determination Test
The bulk density of a soil is the mass per unit volume of the soil deposit
including any water it contains. The dry density is the mass of dry soil contained in a
unit volume. Both are expressed in Mg/m 3, which is numerically the same as g/cm3. It
was determined at the laboratory by using the linear measurement method approached
by B.S. 1377 : 1990 Part 2 : Test 7:2
5
2.3.3. Unconsolidated Undrained Triaxial Compression Test (UU)
Unconsolidated undrained triaxial compression tests were conducted to
determine the undrained shear strength of the soil. This test is performed with the
drain valve closed for all phases of the test and before the sample has a chance to
consolidate. That is, the undisturbed samples (on 38mm diameter x 76mm length)
are sheared under undrained condition. It is based on the test method approached by
B.S 1377 : 1990 Part 7 : Test 9.
3.0 RESULTS OF SOIL INVESTIGATION
3.1 Subsoil Condition
This section briefly describes the soil conditions encountered at site. Detailed
soil conditions are presented in each log of boring in the Appendices of Borehole Logs.
The summary of borehole data is given in the form of a Generalised Sub-Soil
Profiles (see Cross-Sections) which interpolate conditions between boreholes but the
results are not necessarily accurate representations of true conditions on site.
Based on the data collected from 4 number of boreholes, it can be classified
that there are 6 types of soil strata, which are the products of highly to completely
weathered underlying sedimentary rocks, predominantly distributed the project area.
The bore log data and their generalized subsoil profiles are shown in APPENDIX -
C.
(1) Fill
(2) Silty Clay
(3) Clayey Silt
(4) Sandy Clay
(5) Silty Sand, Sand
(6) Clayey Sand
6
(1) Fill
The surface of the project area up to 1.8 to 2.0 meters are covered with back
fill soil mixed with hardcore materials.
(2) Silty Clay
This is a mojor soil type and can be seen in all boreho;es except BH-3. It is a
thick layer and consists of soft to stiff, yellowish to reddish brown, Silty Clay with
fine sand. Thickness is about 3.0 to 18.0 meters. SPT values ranged from 2 to 57
blows. The colour changed to greenish grey and the hardness increased with depth.
(3) Clayey Silt
This is a minor soil type and can be seen only in BH-4. It consists of firmto
very stiff, yellowish brown, mottled with purple, Clayey Silt. Thickness is about 12.0
meters and SPT values ranged from 6 to 23 blows.
(4) Sandy Clay
This is also a minor soil type and can be seen only in BH-1 and BH-3. It
consists of very soft to very stiff, yellowish to reddish brown, light grey, Sandy Clay.
Thickness is about 3.0 to 7.0 meters. SPT values ranged from 2 to 28 blows.
(5) Silty Sand, Sand
This is also a majot soil type which can be seen in all boreholes. It consists of
medium dense to very dense, white to light grey, greenish to bluish grey, Silty Sand &
Sand. Thickness is about 8.0 to well over 18.0 meters. SPT values ranged from 26 to
100 blows.
7
(6) Clayey Sand
This is a bottom most layer and can be seen in BH-1 and BH-3. It consists of
very dense, dark green Clayey Sand with coarse gravels. Probably it might be a
completely weathered granite. Thickness can not be estimated as the boreholes were
terminated in this layer. SPT values showed 100 blows.
General Geology
Based upon the Geological Map of Singapore by PWD (1974) and the present
investigation, highly to completely weathering product soils of the interbedded unit of
the variegated mudstone, siltstone and quartz-sandstone from 'Rimau Facies' of
Jurong Formation are well distributed at the project site. These sedimentary rocks, are
underlied by Bukit Timah Granite and when the later was completely weathered, it
occurred as Silty and Clayey Sand.
3.2 Laboratory Tests
Summary of laboratory test results and details of individual test results are
shown in the APPENDIX-D.
APPENDIX - A
TABLES & CHARTS
CLIENT : URBAN REDEVELOPMENT AUTHORITYPROJECT : SINARAN DRIVETABLE 1. : SUMMARY ON QUANTITY OF FIELD INVESTIGATION
Mech-anic
(Nos)
Hydro (Nos)
UU* (Nos)
CIU* (Nos)
BH 1 27/07/05 29/07/05 - 36.29 36.29 12 9 3 3 3 - - - - 3 - - - - - BH 2 26/07/05 28/07/05 - 34.50 34.50 11 6 3 3 3 - - - - 3 - - - - - BH 3 22/07/05 25/07/05 - 30.23 30.23 10 7 3 3 3 - - - - 3 - - - - -BH 4 29/07/05 01/08/05 - 37.50 37.50 12 7 3 3 3 - - - - 3 - - - - -
138.52 138.52 45 29 12 12 12 0 0 0 0 12 0 0 0 0 0Note :SPT = Standard Penetration Test UD = Undisturbed Sample CU = Consolidated Undrained Triaxial TestDS = Disturbed Sample UU = Unconsolidated Undrained Triaxial Test
pH (Nos)
SO3
(Nos)CL-
(Nos)
Reduce Level (m)
Total Depth of Bore
Hole (m)
Period of Fieldwork
SPT(Nos)
Insitu Test & InstallationChemical Test
Bore Hole No.
Physical Test
Uniaxial Compression Test
Mechanical TestTriaxial Tests
Laboratory Test
Grain Size
Commence CompleteAtter-berg Limit (Nos)
Specific Gravity (Nos)
Bulk/Dry Density (Nos)
Moisture Content (Nos)
Depth of Drilling in
Soil (m)
DS (Nos) UD (Nos)
Client : Urban Redevelopment AuthorityProject : Sinaran Drive
Location : Near Novena MRT Station
TABLE 2. MONITORING RECORD FOR WATER LEVEL AT BOREHOLE (During Operation)
28/07/05 9:00 AM 15.00 1.3029/07/05 9:00 AM 30.00 1.50
27/07/05 9:00 AM 15.00 1.3028/07/05 9:00 AM 30.00 1.40
23/07/05 9:00 AM 21.00 1.3025/07/05 9:00 AM 27.00 1.30
30/07/05 9:00 AM 15.00 1.3001/08/05 9:00 AM 33.00 1.40
Water Level (m)
Borehole Number Date Time Borehole Depth (m)
BH 1
BH 2
BH 3
BH 4
APPENDIX - B
LOCATION PLAN
APPENDIX - C
BOREHOLE LOG
KEY TO BORING LOG
BORE HOLE LOG
( BH-1 to BH-4 )
GENERALIZED SOIL PROFILE
( CROSS _ SECTION )
APPENDIX - D
LABORATORY TEST RESULTS
Summary of Laboratory Test Results
SUMMARY OF LABORATORY TEST RESULTS
UCT
Borehole Sample Depth No. No. (m)
UD1 3.00-3.50 1.77 1.26 40 61 0
UD2 6.00-6.50 1.81 1.30 39 44 0
UD3 9.00-9.50 1.78 1.32 35 55 0
UD1 3.00-3.50 1.92 1.47 31 76 0
UD2 6.00-6.50 1.90 1.43 33 89 0
UD3 9.00-9.50 1.86 1.37 36 89 0
UD1 3.00-3.50 1.84 1.38 33 24 0
UD2 6.00-6.50 2.02 1.63 24 27 0
UD3 9.00-9.50 1.94 1.50 29 22 0
UD1 3.00-3.50 1.82 1.34 36 61 0
UD2 6.00-6.50 1.82 1.30 40 72 0
UD3 9.00-9.50 1.82 1.33 37 72 0
Client: M/s Urban Redevelopment Authority * Multi Stage UCT - Unconfined Compression Triaxial TestLocation: SI Work at Sinaran Drive ^ Field Vane UU - Unconsolidated Undrained Triaxial Compression TestJob No: URA000EPO05000681, Date 19-07-2005 ~ Lab. Vane CIU - Consolidated Isotropic Undrained Triaxial Compression Test
CID - Consolidated Isotropic Drained Triaxial Compression Test
BH 3
BH 4
Bul
k D
ensi
ty (M
g/m
3 )
Liqu
id L
imit
(%)
Pla
stic
Lim
it (%
)
Pla
stic
ity In
dex
(%)
Spec
ific
Gra
vity
Moi
stur
e C
onte
nt (%
)
Atterberg Limit
Dry
Den
sity
(Mg/
m3 )
BH 1
BH 2
CID
Gra
vel (
%)
San
d (%
)
Silt
(%)
Coh
esio
n (k
N/m
2 )
Coh
esio
n (k
N/m
2 )
Coh
esio
n (k
N/m
2 )
Phi
Ang
le (
o )
Grain Size Distribution
Cla
y (%
)
Water
pH V
alue
pH V
alue
Sul
phat
e C
onte
nt in
Chl
orid
e C
onte
nt
2:1
wat
er:s
oil e
xtra
ct
Sal
inity
Sul
phat
e C
onte
nt
Pre
cons
olid
atio
n P
ress
ure
(kN
/m2)
Vane
Phi
Ang
le (
o )
UU CIU
Rem
ould
ed S
hear
S
treng
th (k
N/m
2)
Triaxial Compression
Coh
esio
n (k
N/m
2 )
Initi
al V
oid
Rat
io
Phi
Ang
le (
o )
Com
pres
sion
Inde
x
Und
istu
rbed
She
ar
Stre
ngth
(kN
/m2)
Con
tent
(%)
Unc
onfin
ed C
ompr
essi
on
Test
- R
ock
Cor
e (M
pa)
Tota
l Sul
phat
e
Chemical Soil
Consolidation
Moisture Content / Bulk Density
Unconsolidated Undrained Triaxial Compression Test