HOUSING & DEVELOPMENT BOARD SOIL INVESTIGATION ...

Report on Date: 25 September 2019

Site Investigation Works

Document Reference: RPT-P2019-SI-015-HDB- Tampines Street 62-0.

CLIENT: HOUSING & DEVELOPMENT BOARD

SOIL INVESTIGATION WORKS

AT TAMPINES STREET 62 Boreholes: BH-1, BH-2, BH-3 & BH-4

(Revision.0

25 September 2019

Prepared By Checked By Approved By

Name: Aye Chan Aung Name: Pyae Phyo Aung Name: Elio Tarabay Farid

Designation: Reporting Engineer Designation: Snr. Geologist Designation: Project Manager

Signature: Signature: Signature:

“The results reported herein have been performed in accordance with the terms of accreditation under

the Singapore Accreditation Council. The report shall not be reproduced except in full, unless the

management representative of the accredited organization has given approval in writing”.

No. 50 Ubi Crescent, #01-09, Ubi Techpark, Singapore 408568 TEL +65-6546-5585 FAX +65-6546-5595 E-mail: adm i n@ geomo t i o n . co m . s g Web: ww w.g eomot i on . com . sg




Certification by Professional Engineer for Site Investigation Report

I, x HO HONG CHIN the Professional Engineer, PE Registration

No. 4739 certify that the Site Investigation Report

____________________________________________________________________________

SOIL INVESTIGATION WORKS

AT TAMPINES STREET 62 Boreholes: BH-1, BH-2, BH-3 & BH-4

(Revision.0

comprising all field and laboratory data, tests and results therein has been carried out by me or

under my supervision or direction, and I have verified the accuracy of the information given in the

site investigation report, and to the best of my knowledge and belief, all have been prepared in

compliance in all respects with the provisions of the Building Control Act and Regulations, relevant

Codes of Practice and Standards.

I further certify that I have the appropriate qualifications and experience, and I am familiar with the

purpose of the investigation for which this Site Investigation Report is prepared in reference to

Project Ref. No: RPT-P2019-SI-015-HDB-Tampines Street 62 -0.

Total number of pages in the Site Investigation Report is 41 _

(Report cover, Content page(s) and Appendixes covers are excluded in the page count)

____________________________________________________

Professional Engineer for Site Investigation Signature and Stamp Date: 25 September 2019




CONTENTS

1. SCOPE OF WORK 001

2. LOCATION 001

3. FIELD WORK 002

3.1 Preliminaries 002

3.2 Boring Work 002

3.3 Undisturbed Soil Sampling 3

3.4 Standard Penetration Test 4

3.5 Water Standpipe Installation 5

4. LABORATORY TEST 5

5. INVESTIGATION RESULTS 6

5.1 Distribution of Subsurface Soil 6

5.2 Ground Water Level 0 9

6. COMPLETION AND REINSTATEMENT 0 9

LIST OF FIGURES

Fig. 1 Illustration of Boring Works 003

Fig. 2 Illustration of Undisturbed Sampling 3

Fig. 3 Illustration of Standard Penetration Testing 005

LIST OF TABLES

Table.1 Quantity of Field and Laboratory Testing Works 10 17

APPENDIXES

APPENDIX – A Symbol and Guideline Used in Report 11 ………………………

APPENDIX – B Borehole Location 22

APPENDIX – C Borehole Log, Geological Cross Section & Water 23

Standpipe and Water Level Reading

APPENDIX – D Laboratory Test Results 37

APPENDIX – E SPT Sample Photographs 40


Site Investigation Works Page: 1

Document Reference: RPT-P2019-SI-015-HDB-Tampines Street 62-0

SOIL INVESTIGATION WORKS AT TAMPINES

STREET 62 Boreholes: BH-1, BH-2, BH-3 & BH-4

(Revision.0

1. SCOPE OF WORK

The soil investigation work is as part of gathering preliminary information on soil and

rock condition for the construction of future infrastructure. The work was issued as “Soil

Investigation Works at Tampines Street 62”.

The client is Housing & Development Board and Fong Consultants acts as engineering

team for drafting of the scope of work and supervision. Geomotion (S) Pte Ltd is the

contractor for conducting the site investigation work under the instruction from the

owner’s engineering team.

Client: HOUSING & DEVELOPMENT BOARD

Main Contractor: GEOMOTION (SINGAPORE) PTE LTD

No.50 Ubi Cresecnt #01-09 Ubi Techpark

Singapore 408568

Field Work: 02 September 2019 to 16 September 2019

Laboratory Work: 17 September 2019 to 23 September 2019

Report Work: 24 September 2019 to 25 September 2019

Total four (4) numbers of boreholes BH-1, BH-2, BH-3 & BH-4 were proposed

including the services of Standard Penetration Test (SPT), collection of undisturbed soil

samples, monitoring of Water Standpipe and subsequent laboratory testing. A total (2)

drilling rigs were mobilized to conduct the site work.

The works were carried out in accordance with BS 5930:2015 “Code of Practice for Site

Investigation” and BS 1377: 1990 for laboratory works & field testing; Eurocode 7 and

relevant ASTM Standard.

2. LOCATION

The project is located at Tampines Street 62, As-built coordinates, ground levels and

locations are in the list and drawings which attached in Appendix-C.

1




3. FIELD WORKS (BS EN ISO 22475-1:2006)

3.1 PRELIMINARIES

Prior to Geotechnical investigation works, the proposed locations will be set out through

a survey. Survey work is carried out by 3-D station survey equipment. Adopting the co-

ordinates and reduced level from a known benchmark produced by relevant party or

authority. Transferring the value to intermediate (turning) point is necessary until the

final location of the investigation points.

After setting out the borehole locations, utilities detection works will be carried out at

each proposed location covering an area of 2m x 2m in order to find out for utilities

appearance like power, telephone and TV cables. This procedure is to be carried out

only in urban area and generally not in the reclamation area unless and otherwise other

reasons request to do so. This would ensure that during the drilling and penetration, the

utilities would not be accidentally damaged.

Precision locator RD 400 PL or similar is used to detect the electromagnetic field that is

produced by a cable. The Licensed Cable Detection Worker carries out the detection

work. Submitting the notification to Powergrid is also required prior to the

commencement of earthworks. Only when free of cables, manual excavation of trial pit

to a depth of about 1.5 meter from ground surface will be performed to confirm no other

underground services at the boring points. Hand auger is applied to further down 1.5-m

if necessary. Once it is confirmed that the area is free of underground services,

investigation work would commence.

3.2 BORING WORK

This investigation was performed using rotary drilling rig. A cutting tool was attached to

the drilling rod to produce 100mm diameter borehole. Circulated mud water was

pumped through the hollow rods into the hole to stabilize the borehole and to wash out

the soil debris to the ground surface by pressure.

Partial casing was used to stabilize the borehole in addition to using mud circulation. A

sketch giving the illustration of boring work is presented in Figure 1. The borehole was

terminated when the specified criteria was met.

The collection of undisturbed samples, SPT tests and insitu tests were carried out as per

specification till end of boreholes.

During the investigation, a field log was recorded, prepared and kept by the Site

Supervisor including the information of soil descriptions, stratum changes, and other

field test results.

2




Figure-1: Illustration of Boring Work

3.3 UNDISTURBED SOIL SAMPLING (UD) (BS EN ISO 22475-1:2006)

The purpose of undisturbed soil sampling is to retrieve soil sample at in-situ condition

and test for physical and mechanical properties in the laboratory. Prior to sampling,

preparing sampling tube and the borehole will be flushed with water to remove any

remnants left at the bottom of the borehole, the depth at which the undisturbed soil will

be collected is then recorded with proper label.

The sampler tube will be lowered down to the bottom of the borehole and jacked into

soil. After the sampler tube has been pushed into the soil about the length of the sampler

itself, pushing will be stopped and the sampler shell shall be sheared off by rotating the

rod or by slow raising the sampler, and carefully withdrawn without any vibrations or

shocks, to ground surface. Some soil will be removed at each end of the sampler tube

and placed in a plastic container for visual soil classification and record purposes. Then

molten fine wax is then applied in thin layers to form a seal on both sides of the sampler

tube. This is to minimize the loss of moisture inside the soil sample. The sample tube

will be kept under the shade or rain during working time and send back to store by

proper transport.

Figure-2: Illustration of Undisturbed Sampling

3




3.4 STANDARD PENETRATION TEST (SPT) (BS EN ISO 22476-3:2005)

The test is to carry out in accordance with BS EN ISO 22476-3:2005, which includes the

determination of the penetration resistance of a steel split-barrel sampler and retrieval of

disturbed soil sample for identification purpose. The SPT Hammer Energy Measurement

must be calibrated annually.

It is performed using split-barrel sampler connected to the lower end of boring rods shall

be lowered to the bottom of the borehole and then hammer assembly added and recorded

the initial penetration. The sampler will be driven into soil by means of a 63,5kg + 0,5

kg steel hammer dropping freely from a height of 760mm onto an anvil attached at the

top of the rods. A trip-release mechanism and guiding assembly will be used to control

the falling hammer and when dropped, the driving energy will be transmitted via the

rods to the split-barrel sampler at the bottom end. The sampler will be driven 450mm

into the soil with the number of blows counted at each successive penetration of 75mm.

The resistance measured as SPT N-value will be taken as the number of blows for the

last 300mm penetration.

The seating drive shall be a penetration of 150mm or 25 blows whichever is reached

first. The test will proceed to the test penetration (300mm), in which the number of

blows for each 75mm penetration is taken. Both the seating drive blow counts and

penetration, and the test penetration blow counts will be recorded. T N-value to be

recorded is taken as the sum of the number of blows for the 300mm test penetration.

For example : Blows/75mm : 5,7,8,9,13,15

N=45

A hard layer is defined as on with an N-value 100 or more.

For example : Blows : 25/50, 45/75, 55/45

Where seating Drive = 25 at 50mm penetration

N=100 blows at 120mm penetration

For very soft soils, if split spoon sampler moves on its own before hammer drop, shall

be recorded as “Self Weight” or “Rod Weight=RW”. If the hammer fixed on hammer

blade and the split spoon sampler moves on, shall be recorded as “Hammer

Weight=HW”.

For hard rock, if no penetration is observed after several blows, the SPT shall be

recorded as “Refusal” of “Rebound”.

The soil in the split spoon shall be collected as disturbed sample in a plastic container

and stored at the first row of storage space within the core box that is used for storage of

rock cores. Alternatively the SPT samples shall be stored in appropriate boxes and

properly labeled.

4




Figure-3: Illustration of Standard Penetration Test

3.5 WATER STANDPIPE INSTALLATION

Total eight number of Water Standpipe were installed at 10.00m below ground level in

borehole BH-4 Grout the existing terminated borehole till the specified installation

depth and wait for grout set. Lower down the water standpipe to the required depth.

Water standpipe consists of 50 mm diameter PVC Pipe. 3-mm holes will be allocated at

the spacing of 25 mm along the pipe. This perforated section at the lower end of the

pipe up to 2/3 of total length and covered by geo-fabric cloth (green net). Place sand

covering the perforated section. Withdraw all borehole casings once the water

standpipe has been firmly put into place meter by meter. Place the rest of the remaining

borehole with bentonite and cement grout until the top of the borehole reaching the

ground level. Install protective box to cover the top of the water standpipe.

Installed depth will be check after the installation. Initial reading will be taken 3-day

after the installation. The details of water standpipe installation and water level reading

are attached in Appendix-C.

4.0 LABORATORY TESTS

Various mechanical, physical and chemical tests were performed on the undisturbed

samples. The detailed services conducted are as stated below.

4.1 Chemical Test (BS 1377: Part 3: 1990)

Organic Content, Chlorite Content, Total Soluble Sulphate (gravimetric method) and pH

were also conducted in accordance with BS 1377 part 3 1990.

5




5.0 INVESTIGATION RESULTS

5.1 Distribution of Subsurface Soil

The soil classification was made by visual inspection in accordance with “Code of

practice for Site Investigation BS 5930: 1999”. Typically, the properties of consistency

or relative density, color, texture and principal soil type and any minority were described

orderly. Follow-up adjustment was made in soil description, if there were Atterberg

limit test, particle size distribution test and undrained shear strength.

As for finer soils, Atterberg limit A-line is used for the classification between Clay and

Silt. The consistency is also adjusted if there is any undrained shear strength from any of

laboratory test. If there are discrepancies on consistency between undrained shear

strength from laboratory results and N-value of standard penetration test from in-situ test,

the combination is used.

Geological classification was made in accordance with the following guidelines and

criterion. If necessary, further adjustment to geological formation was again carried out

after reviewing with Regional Geology.

• Singapore Engineering soil units –It includes estuarine (E), Marine Clay (M), Fluvial

Sand (F1) and Fluvial Clay (F2) which presumably from Kallang Formation. However

some materials which classified under E, F1 and F2 units could also be part of Tekong

Formation and others. The classification is based on engineering properties and not by

Geological Standard.

• Geology of Singapore (2nd Edition) - DSTA 2009.

• Updating the Engineering Geology of Singapore - Proceedings of Underground

Singapore and Workshop Nov 2003

At this project site, the following Geological formation and soil unit were encountered.

5.1.1 MADE GROUND

Made Ground is man-made layer and observed in all boreholes BH-1, BH-2, BH-3 &

BH-4. It composed of reddish brown, sandy SILT and silty SAND with SPT N-value

ranges from 4 in borehole BH-2 to 28 in borehole BH-3. Thickness is from 5.00m in

boreholes BH-1 & BH-2 to 13.00m in borehole BH-3.

5.1.2 OLD ALLUVIUM (OA)

It is terrestrial to deltaic soil which deposited under alluvial conditions. Due to

weathering effect, the strength is lower when the soil is nearer to the ground level and

getting higher when it is in deeper depth. The soil is categorized into five groups

depending on their weathering impact and strength.

Though SPT N is used as a general guide line for to identify the weathering grade, it is

not applied to all cases. If appearance of weathering signs is clear and visible,

6




classification is made based on weathering impact and not following SPT N as guide

line. Their occurrences are as below.

It was noted that at times, layers of hardpan was found in the weathered Old Alluvium,

and very high SPT values may be due to hardpan rather than a change in weathering

grade. Conversely, there may be a sudden drop in SPT N-value if a layer of uniform

sand is encountered in a borehole which is not completely filled of stabilising fluid

(Guidance Note on Weathering Classifications and Description, LTA 2003).

Old Alluvium (OA) was observed in all both boreholes BH-1& BH-2.

5.1.2.1 Residual {OA(E) –SPT N <10}

It is a soil from completely weathered zone. The strength is the lowest among the

members in the formation. SPT N-value is < 10. It composed of reddish brown mottled

yellow, reddish orange loose to medium dense slightly gravelly silty/clayey fine to

coarse SAND. The Residual Soil of Old Alluvium OA(E) was not observed in these

boreholes.

5.1.2.2 Destructured {OA(D) –SPT N 10 to 30}

It is a soil from highly weathered zone. The strength is the relatively low among the

members in the formation. SPT N is ranging from 10 to 30. The Destructured (OA-D)

layer composed of reddish brown spotted greenish white, very stiff, slightly gravelly

sandy SILT. This layer was observed in borehole BH-1 with SPT N-value 25 and

thickness is 3.00m in this borehole.

5.1.2.3 Distinctly Weathered {OA(C) – SPT N 30 to 50}

It is a soil from moderately weathered zone. The strength is the moderate among the

members in the formation. SPT N is ranging from 30 to 50 The Distinctly Weathered

layer composed of reddish brown mottled yellowish, light grey mottled greenish,

brownish grey, reddish brown mottled white, yellow mottled grey and black, brownish

grey spotted white, greyish white, hard, gravelly sandy SILT and dense, silty gravelly

SAND, slightly gravelly silty SAND, silty fine to coarse SAND, silty fine SAND and

silty medium to coarse SAND. This layer was observed in boreholes BH-1, BH-3 & BH-

4 with SPT N-value ranges from 30 in borehole BH-1 to 47 in boreholes BH-1 & BH-3

and thickness is 6.00m in borehole BH-3 to 11.00m in borehole BH-1.

5.1.2.4 Partially Weathered {OA(B) – SPT N50 to N100}

It is a soil from slightly weathered zone. The strength is the relatively high among the

members in the formation. SPT N is ranging 50 to 100. The Partially Weathered layer

composed of greenish grey, light grey mottled greenish, greenish grey mottled brown,

reddish grey spotted white, brownish grey spotted white, brownish grey, light grey

mottled yellow, yellow, very dense, slightly gravelly silty SAND, gravelly silty SAND,

silty SAND, slightly silty SAND, silty fine to coarse SAND, silty fine SAND and silty

medium to coarse SAND. This layer was observed in all boreholes BH-1, BH-2, BH-3 &

BH-4 with SPT N-value ranges from 53 in borehole BH-4 to 89 in borehole BH-2 and

thickness is 21.00m in boreholes BH-3 & 4 to 35.00m in BH-2.

7




5.1.2.5 Unweathered {OA(A) – SPT N >100}

It is soil from un-weathered zone. It is apparently cemented also. The strength is the

highest among the members in this formation. SPT N is greater than 100. The

Unweathered OA (A) layer composed of greenish grey, light brown mottled white,

reddish brown mottled purple, brownish grey, reddish brown mottled purple, and yellow

mottled grey, very dense, gravelly silty SAND, slightly silty SAND and hard, sandy

SILT and slightly sandy SILT. This layer was observed in all boreholes with SPT N-

value of >100 blows in these boreholes and thickness from 6.29m in borehole BH-4 to

6.45m in borehole BH-1.

5.1.3 Summary

1. The Project site was mainly underlain by Fill (Back Fill) and Old Alluvium (OA)

Formation.

2. The interface in between Fill and Old Alluvium was observed in all boreholes from

5.00m depth in borehole BH-1 to 13.00m depth in borehole BH-3.

3. Boreholes were terminated after achieving 3 consecutive SPT N-value 100/300mm

at 3.00m interval OR as per client’s instruction.

4. Summary of Geological Formation.

N - value N - value N - value N - value N - value

From ToThickness

(m)From To

Thickness

(m)From To

Thickness

(m)From To

Thickness

(m)From To

Thickness

(m)(m)

14 25 30 - 47 60 - 82 100

5.00 3.00 11.00 24.00 6.45

4 - - 58 - 89 100

5.00 - - 35.00 6.43

21 - 28 - 43 - 47 54 - 66 100

13.00 - 6.00 21.00 6.42

23 - 43 - 45 53 - 71 100

7.00 - 9.00 21.00 6.29

- - - - - - - - - - - - - - - -

N-value (Range) 4 - 28 25 30 - 47 53 - 89 100

Thickness Range (m) 5 - 13 3 6 - 9 21 - 35 6.29 - 6.45

43.29

49.45

46.42

46.43

BH-4 0.00 7.00 - - 7.00 16.00

MADE GROUND

19.00

Depth (m) Depth (m)

19.00 43.00 43.00 49.45 0.00 5.00

16.00 37.00 37.00 43.29

5.00 8.00 8.00

46.42

BH No.

BH-1

OLD ALLUVIUM FORMATION

Borehole

Final

DepthDepth (m) Depth (m) Depth (m)

Destructured {OA(D)-(N=10-

30)}

Distinctly Weathered {OA('C)-

(N=30-50)}

Partially Weathered {OA(B)-

(N=>50-100)}

Unweathered {OA(A)-

(N=>100)}

BH-3 0.00 13.00 - - 13.00 19.00 19.00 40.00 40.00

BH-2 0.00 5.00 - - - - 5.00 40.00 40.00 46.43

8




5.2 Ground Water Level

Throughout the site investigation works, water level from boreholes was taken before

drilling in the morning and after drilling at end of the day. 1 no of Water Standpipes was

installed and reading of water level during the course of drilling is reflected in boreholes

logs and water level reading from water standpipe were reflected in Appendix-E.

6.0 COMPLETION AND REINSTATEMENT

Upon completion of site work, all borehole positions were back filled with a certain ratio

of cement:bentonite:water (3:0.75:4) grout in accordance with contract specification.

The ground was leveled. Necessary replanting and reinstatement were carried out in as

in the preconditions and handed back to relevant owners.

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9

TABLE‐1QUANTITY OF FIELD AND LABORATORY TESTING WORKS

Table-1 : SUMMARY OF TOTAL QUANTITY OF FIELD INVESTIGATION & LABORATORY TEST WORKS

CLIENT/OWNER: HOUSING & DEVELOPMENT BOARD

PROJECT: SOIL INVESTIGATION WORK AT TAMPINES STREET 62

BH-1 10/09/19 12/09/19 38896.690 40276.04 114.299 49.45 - 49.45 16 16 3 - - - - - - -

BH-2 10/09/19 13/09/19 38825.400 40199.22 114.137 46.43 - 46.43 15 15 2 - - - - - - -

BH-3 13/09/19 16/09/19 38912.540 40092.22 114.633 46.42 - 46.42 15 15 1 - - - - - - -

BH-4 02/09/19 09/09/19 38983.97 40182.77 115.883 43.29 - 43.29 14 14 1 1 1 2 2 1 2 -

185.59 0.00 185.59 60 60 7 1 1 2 2 1 2 0

EXPLANATION

SPT Standard Penetration Test PSD Particle Size Distribution

DS Disturbed Sample SG Specific Gravity (Psrticle Density)

UD Undisturbed Sample MA Mechanical Analysis (Sieve Analysis)

PS Piston Sample HYDRO Hydrometer Test

WSP Water Standpipe

Org

anic

Conte

ntBOREHOLE

NO.

TE

RM

INA

TIO

N O

F

BO

RE

HO

LE

(m

)

FIELD WORKS COORDINATES

SO

IL D

RIL

LIN

G

RO

CK

CO

RIN

G

Wat

er S

ample

LABORATORY

Rem

arks

Total:

Chemical Analysis

Ph V

alue

DA

TE

OF

CO

MM

EN

CE

ME

NT

DA

TE

OF

CO

MP

LE

TIO

N

NO

RT

HIN

G

EA

ST

ING

RE

DU

CE

D L

EV

EL

(m

)

INSITY TEST / SAMPLES

Tota

l S

ulp

hat

e

Conte

nt

Chlo

ride

Conte

nt

SP

T

DS

UD

Wat

er S

tandpip

e

10

APPENDICES

APPENDIX‐A: Symbol and Guideline Used in Report

APPENDIX‐B: Borehole Location

APPENDIX‐C:

APPENDIX‐D: Laboratory Test Results

APPENDIX‐E: SPT Sample Photograph

Borehole Log, Geological Cross Section & Water Standpipe Installation and Water Level Reading

APPENDIX ‐ A

SYMBOL AND GUIDLINE USED IN REPORT

11

pyaephyo.aung

Line

pyaephyo.aung

Text Box

The document was provided by LTA on 07 Apr 2010

NOTATION USED IN REPORT

Notation for Field Test and Sample Notation for Laboratory Test

Notation Test Notation Test

SPT Standard Penetration Test MC Moisture ContentVST Field In-situ Vane Test LL Liquid LimitPBT Field Permeability Test PL Plastic LimitPKT Packer Test PI Plastic IndexPRM / PMT Pressure Meter Test CUU Unconsolidated Undrained TriaxialTW Thin Wall Undisturbed Sample CCD Consolidated Drained TriaxialPS Piston Sample CCU Consolidated Undrained TriaxialMZ Mazier Sample BD/DD/PD Bulk / Dry / Paricle DensityCR Rock Core Sample Pc' Oedometer Precompression PressureDS Disturbed Sample Cc Oedometer Compression IndexWS Water Sample SDI Slake Durability Index

PLD Point Load Test (Diametrical)PLA Point Load Test (Axial)CAI CERCHAR Abrasivity IndexAVS Norweigian Abrasion Value TestUCS Unconfined Compression Test

Notation for Geological Formation (Geology of Singapore 2008)

Notation Formation Member / Facies / Grade Engineering Soil Unit *

Kf Kallang Formation Reef Member (F1, F2 and E)Kt Kallang Formation Transitional Member (E, F1 and F2)Kl Kallang Formation Littoral Member (F1)Ka Kallang Formation Alluvial Member (F1, F2 and E)Km Kallang Formation Marine Member (M)T Tekong Formation - (F1 and E)HC Huat Choe Formation N.AOA Old Alluvium O(A) - SPT N>100

Old Alluvium O(B) - SPT N 50 to 99Old Alluvium O(C) - SPT N 30 to 50Old Alluvium O(D) - SPT N 10 to 30Old Alluvium O(E) - SPT N <10

FC Fort Canning Boulder Bed FCBBBS 5930:1999 EN ISO 14689-1

MS Jurong Formation Murai Schist S(VI) to S(I) S (5) to S(0)Jt Jurong Formation Tengah Facies S(VI) to S(I) S (5) to S(0)Jsj Jurong Formation St John Facies S(VI) to S(I) S (5) to S(0)Jr Jurong Formation Rimau Facies S(VI) to S(I) S (5) to S(0)Jp Jurong Formation Pandan Facies S(VI) to S(I) S (5) to S(0)Jac Jurong Formation Ayer Chawan Facies S(VI) to S(I) S (5) to S(0)Jj Jurong Formation Jong Facies S(VI) to S(I) S (5) to S(0)Jq Jurong Formation Queenstown Facies S(VI) to S(I) S (5) to S(0)Da/Db Dyke Rocks G(VI) to G(I) G (5) to G(0)BT Bukit Timah Granite G(VI) to G(I) G (5) to G(0)Bt gdt Bukit Timah Granodiorite G(VI) to G(I) G (5) to G(0)Rphf Rafted bodies (with Pyroxene) G(VI) to G(I) G (5) to G(0)Rnp Rafted bodies (with No Pyroxene) G(VI) to G(I) G (5) to G(0)PV Paleozoic Volcanics G(VI) to G(I) G (5) to G(0)GN Gombak Norite G(VI) to G(I) G (5) to G(0)S Sajahat Formation N.A N.ANote :

Engineering soil unit is informal and no proper establishment in term of geology.

The classification is based on the soil properties rather than formal Geological Standard

It is commonly used in Singapore Geotechnical Field

Date of Revision : 26-Aug-2010

(Singapore) Pte Ltd

12

Geomotion (Singapore) Pte Ltd

Terms for designation of particle shape Classification of very coarse soilBS 5930 : 1999

ParameterEN ISO 14688-1:2002

FractionPercent by mass

Terms

Angularity/roundness

Very angular

Angular Angular <5Low boulder content

Sub-angular Subangular 5 to 20Medium boulder content

Sub-rounded Subrounded >20High boulder content

Rounded Rounded <10Low cobble content

Well rounded 10 to 20Medium cobble content

Flat or Tabular

Form Cubic

Elongated FlatElongate

Rough Surface texture RoughSmooth Smooth

Particle size fractions

Particle sizes Particle sizesmm mm

Large boulder

LBo >630

Boulder Bo >200 to 630

Cobble Co 60 – 200 Cobble Co >63 to 200

Gravel G 2 – 60 Gravel Gr >2,0 to 63

Coarse gravel G 20 – 60Coarse gravel

CGr >20 to 63

Medium gravel

G 6 – 20Medium gravel

MGr >6,3 to 20

Fine gravel G 2 – 6 Fine gravel FGr >2,0 to 6,3

Sand S 0.06 – 2 Sand Sa >0,063 to 2,0

Coarse sand S 0.6 – 2 Coarse sand CSa >0,63 to 2,0

Medium sand S 0.2 – 0.6Medium sand

MSa >0,2 to 0,63

Fine sand S 0.06 – 0.2 Fine sand FSa >0,063 to 0,2

Silt M 0.006 – 0.02 Silt Si >0,002 to 0,063

Coarse silt M 0.02 – 0.06 Coarse silt CSi >0,02 to 0,063

Medium silt M 0.006 – 0.02 Medium silt MSi >0,0063 to 0,02

Fine silt M 0.002 - 0.006 Fine silt FSi >0,002 to 0,0063

Clay C <=0.002 Clay Cl <=0,002

BS 5930 : 1999Soil Fractions

EN ISO 14688-2:2004

Sub-fraction Symbols Sub-fraction Symbols

Boulders

Cobble

>20High cobble content

Bo >200 Very coarse soil

Coarse soil

Fine soil

Boulder

13

Geomotion (Singapore) Pte Ltd

Classification of very coarse soil Shape of gracing curve

Fraction Percent by mass TermsShape of grading curve

CU CC

<5Low boulder content

Multi-graded >15 1<CC<3

5 to 20Medium boulder content

Medium graded 6 to 15 <1

>20High boulder content

Even-graded <6 <1

<10 Low cobble content Gap-graded Usually highAny (usually <0,5)

10 to 20Medium cobble content

>20 High cobble content

Classification of soils with organic constituents Correlations to classify terms

Organic ContentEN ISO 14688-2: 2004 (Table 4)

BS5930:1999 (Table 3, Page 114)

(=<2mm)% of dry mass

Density Index

2 to 6 ID

6 to 20 %

>20 Very loose 0 to 15 0 to 4Loose 15 to 35 4 to 10Medium dense 35 to 65 10 to 30Dense 65 to 85 30 to 50

Very dense 85 to 100 >50

Undrained shear strength of fine soilsBS 5930:1999

TermCu : (kPa)

Extremely low <10

Very low 10 to 20Low 20 to 40 20 to 40Medium 40 to 75 40 to 75High 75 to 150 75 to 150Very high 150 to 300 150 to 300Extremely high >300 >300

High-organic

Term

Undrained shear strengthEN ISO14688-2:2004

SPT N-value

Boulders

Cobble

Soil

Low organic

Medium -organic

Hard (or very weak mudstone)

‘a Materials with shear strength greater than 300kPa may behave as weak rocks and should be described as rocks according to ISO 14689-1

Term

Very Soft

Soft

<20

FirmStiffVery Stiff

14

G Geomotion (Singapore) Pte Ltd

Principles of a classification of soils

Criterion Soil Group QuantificationFurther subdivision as appropriate by

Most particles>200mm

Bo xBo

Most particles boCo coBoRequire special consideration

>63mm

Co saCo, grCo sagrCoMost particles >2mm

Gr cosaGrParticle size (grading)

coGrShape of grading curve

Most particles >0,063

saGr, grSa sasiGr, grsiSa Relative density

siSa, clSa, saclGr

Permeability

Sa siGr, clGr

or Sa (Mineralogy)(Particle shape)

Low plasticity dilatant

Si saSi sagrSi Plasticity

SaclSi Water content

clSi, siCl Strength, sensitivity

Plastic non-dilatant sagrCl Compressibility,

Cl orSi, orClStiffness (Clay mineralogy)

Dark colour, low density

Organic Or saOr, siOr clOrRequires special considerationRequires special consideration

Relaid natural materials

As for natural soils

Key to symbols

Principal

SoilBouldersCobbles BoGravel Co

Sand Gr

Silt SaClay SiOrganic Cl

Made ground

Or

Mg -‘x any combination of components

Cases requiring special consideration should be classified according to national or project requirement

‘bo‘co‘gr Gr(gr) and Sa (sa) can be ubdividual into fine F(f),‘sa medium M(m) or coarse C(c)‘si ‘cl

Denomination into groups of similar properties

Wet soil does not stick together

Very coarse

Coarse

Wet soil sticks together

Fine

Not naturally

Made ground deposited Mg xMg

Man made material

Secondary or tertiary component

Or

15

G (Singapore) Pte Ltd

16

Scale of weathering stages of rock mass

Standard

Description Description

Classification for Rock Mass and Rock Materials

Classification for Rock Mass Weathering Grade

Unchanged from Original State

I Fresh 0

No visible sign of rock material weathering, perhaps slight discoloration on major discontinuity surfaces

Slight discoloration, slight weakening

IISlightly Weathered

1Discoloration indicate weathering of rock materials and discontinuity surfaces

Considerably weakened, penetrative discoloration Large pieces can not be broken by hand

IIIModerately Weathered

2

Less than half of the rock material is decomposed or disintegrated. Fresh or discolored rock is present either as a continuous framework or as a core stone.

Large pieces cannot be broken by hand. Does not readily slake when dry sample immersed in water

IVHighly Weathered

3

More than half of the rock material is decomposed or disintegrated. Fresh or discolored rock is present either as a continuous framework or as a core stone.

Considerably weakened Slakes Original texture apparent

VCompletely Weathered

4

All rock material is decomposed and/or disintegrated into soil. The original mass structure is still largely intact.

Soil delivered by in sity weathering but retaining none original testure of fabric

VI Residual Soil 5

All rock material is converted to soil. The mass structure and material fabric are destroyed. There is a large change of volume, but the soil has not been significantly transported.

The destructive terms are provided and defined in 14689-1(Table 2) as Fresh, Discoloured, Disintegrated, decomposed to describe the results of weathering / alteration of rock material. These terms may be subdivided using qualifying terms of “partially, wholly and Slightly”

Widely and commonly use in local practice for classification of rock

materials and rock mass weathering grade

BS 5930:1999 (Approach 2 : Classification for Uniform Materials

EN ISO 14689-1:2003

Grades Symbol

TermGrades Symbol

17

pyaephyo.aung

Line

Unconfined Compression Strength for Rock Point Load Strength of Intact Rock Material

(BS 5930 :1999) (EN ISO 14689-1) (ASTM D5878-95)

Term UCS (MPa)UCS (MPa)

Term Term

Less than 1 Extremely weak

Very Weak < 1.25 1 to 5 Very weak Very high

Weak 1.25 - 5 5 to 25 Weak High

Moderately Weak 5 - 12.5 - - Medium high

Moderately Strong 12.5 to 50 25 to 50 Medium strong Moderate

Strong 50 to 100 50 to 100 Strong Low

Very Strong 100 to 200 100 to 250 Very strong

Extremely Strong > 200 >250 Extremely strong

Structural Terms of Rock Discontinuities of Rock

(BS 5930 :1999) (EN ISO 14689-1) (BS 5930 :1999) (EN ISO 14689-1)

TermSpacing (mm)

Spacing (mm)

Term TermSpscing (mm)

Term

Very Thick > 2000 > 2000 Very thick Very widely spaced > 2000 Very wide

Thick 600 to 2000 2000 to 600 Thick Widely spaced 600 to 2000 Wide

Medium 200 to 600 600 to 200 Medium Medium spaced 200 to 600 Medium

Thin 60 to 200 200 to 600 Thin Closely spaced 60 to 200 Close

Very thin 20 to 60 60 to 20 Very thin Very closely spaced 20 to 60 Very close

Thickly laminated < 20 20 to 6 Thickly laminated

Thinly laminated < 6 < 6 Thinly Laminated

Terms - CERCHAR Abrasivity for Rock Term - Norweigian Abrasivity for Rock

(CERCHAR 1986) (NTNU/SINTEF)

Term

Extremely low

Very low

Low

Medium

High

Very hight

Extremely high

Date of compilation:15-Nov-

TERMS & GUIDE LINES - ROCKS

extremely abrasive

quartzitic

Term CAI

0.5 - 1.0

1.0 - 2.0

2.0 - 4.0

not very abrasive

slightly abrasive

medium abrasive to abrasive

very abrasive

4.0 - 6.0

6.0 - 7.0

26.0 - 35.0

36.0 - 44.0

0.3 - 0.5

> 44.0

Extremely closely spaced

< 20Extremely

close

NAV

< 1

2.0 - 3.0

4.0 - 12.0

13.0 - 25.0

1 - 2

<1

Point Load Index (MPa)

>10

4 - 10

2 - 4

18

The following guidance is provided by LTA Civil Design Division of Contract 2111C Site Investigation works For Road and Projects (7). This note is used for reports which are prepared under ER320 contract with the permission of LTA Civil Design Division.

B FC

E

FS

F1

F2G GRANITE

M

ORemarks:

REFERENCESOIL & ROCK

TYPEGENERAL

DESCRIPTION

GEOLOGICAL FORMATION (PWD, 1976)

ESTUARINE (Transitional)

BEACH (LITTORAL)

KALLANG Littoral, possibly also part of all other members and TEKONG

Sandy, sometimes silty, with gravels, coral and shells.

KALLANG Transitional, possibly part of Alluvial and Marine

Peats, peaty and organic clays, organic sands.

OLD ALLUVIUM

MARINE

FLUVIAL (Alluvial)

Bed of Alluvial Member of KALLANG

Sands, silty sands, silts and clays.

Bed of Alluvial Member of KALLANG

Predominantly granular soils including silty sands, clayey sands and sandy silts.

KALLANG Marine Member

Very weak to weak beds of sandstone and mudstone.

OLD ALLUVIUM

Cohesive soils including silty clays, sandy clays and clayey silts.

Very soft to soft blue or grey clay.

JURONG Tengah, Rimau, Ayer Chawan and Queenstown Facies (plus the Pandan Limestone, which was not identified in PWD (1976)

Sandstones, siltstones mudstones, conglomerate and limestone. The rock has been subjected to a varying degree of metamorphism.

The classification is mainly based on the soil and or rock properties rather than formal Geological Standard.

The classification is also known as "Engineering Soil Unit or Geotechnical Soil Units".

GEOLOGICAL CLASSIFICATION OF SOILS / ROCKS

KALLANG Alluvial, possibly part of all other members and TEKONG

Granitic rocks, including granodiorite, adamellite and granite.

BUKIT TIMAH GRANITE

REFERENCE

SEDIMENT-ARIES (Rocks & associated soils)

SOIL & ROCK TYPE

GENERAL DESCRIPTION

GEOLOGICAL FORMATION (PWD, 1976)

FORT CANNING BOULDER BED (also known as S3, Bouldery CLAY or Boulder Bed

A colluvial deposit of boulders in a soil matrix. The matrix is typically a hard silty clay, but can be granular. The material is largely derived from the rocks and weathered rocks of the Jurong Formation.

Not shown in PWD (1976)

19

The following guidance is extracted from Contract C2111C Site Investigation works For Road and Projects (7) issued

as Annex-D. The note is used for reports which are prepared under C2111C contract with the permission of LTA

Civil Design Division.

Table 1 - Weathering Classification (Bukit Timah Granite and Gombak Norite)(BS 5930:1999) (EN ISO 14689-1)

Basis for assessment

G(I) Intact strength, unaffected by weathering. Not broken easily by hammer - G(0)rings when struck. No visible discoloration.

G(II) Not broken easily by hammer - rings when struck. Fresh rock colors generally G(1)retained but stained near joint surfaces.

G(III) Cannot be broken by hand. Easily broken by hammer. Makes a dull or slight G(2)ringing sound when struck with hammer. Stained throughout.

G(IV) Core can be broken by hand. Does not slake in water. Completely discolored G(3)

G(V) Original rock texture preserved, can be crumbled by hand. Slakes in water. G(4)Completely discolored.

G(VI) Original rock structure completely degraded to a soil, with none of the original G(5) fabric remains. Can be crumbled by hand.

Table 2 - Weathering classification for Jurong Formation (Except Pandan Limestone)(EN ISO 14689-1)

S(I) Intact strength, unaffected by weathering S(0)

S(II) Slightly weakened, slight discoloration, particularly along joints. S(1)

S(III) Considerably weakened & discolored, but larger pieces cannot be broken by hand. S(2)RQD is generally >0, but RQD should not be used as the major criterion for assessment.

S(IV) Core can be broken by hand or consists of gravel size pieces. Generally highly to very S(3)highly fractured, but majority of sample consists of lithorelics. RQD generally = 0, but RQD should not be used as major guide for assessment. For siltstone, shale, sandstone,quartzite and conglomerate, the slake test can be used to differentiate between Grade V (slakes) and Grade IV (does not slake).

S(V) Rock weathered down to soil-like material, but bedding intact. S(4)Material slakes in water.

S(VI) Rock degraded to a soil in which none of the original bedding remains. S(5)

Table 3 - Weathering Classification for Old Alluvium

A Unweathered Original strength > 50 (cannot usually be penetrated by

B Partially Weathered Slightly reduced strength CPTs with 20t load capacity)

C Distinctly weathered Further weakened 30 to 50

D Destructured Greatly weakened, often mottled, 10 to 30bedding disturbed

E Residual No bedding remains <10

* The SPT result should not be used in isolation to access weathering.

WEATHERING CLASSIFICATION OF SOILS / ROCKS

Grade

Grade

Class Classifier Characteristics Indicative SPT, Blows/300mm *

Grade

Basis for assessment Grade

20

Field identification of the unconfined compressive strength

Unconfined compressive strength

MPa

Extremely weak Indented by thumbnail Less than 1

Very weakCrumbles under firm blows with point of geological hammer, can be peeled by a pocket knife

1 to 5

WeakCan be peeled by a pocket knife with difficulty, shallow id=ndentations made by firm blow with point of geological hammer

5 to 25

Medium strong

Cannot be scraped or peeled with a pocket knife, specimen can be fractured with single firm blow of geological hammer

25 to 50

StrongSpecimen requires more than one blow of geological hammer to fracture it

50 to 100

Very strongSpecimen requires many blows of geological hammer to fracture it

100 to 250

Extremely strongSpecimen can only be chipped with geological hammer

>250

Examples of terms which may be used in the description of rock mass structureSedimentary Metamorphic IgneousBedded Cleaved MassiveInterbedded Foliated FlowbandedLaminated Schistose FoldedFolded Banded LineatedMassive LineatedGraded Gneissose

Folded

Term Field Identification

A Some extremely weak rocks will behave as soils and should be described as soils according to ISO 14688-1

21

APPENDIX ‐ BBOREHOLE LOCATION

BH ID RL

BH-1 114.299

BH-2 114.137

BH-3 114.633

BH-4 115.883

38912.54 40092.22

38983.97 40182.77

38825.4

Borehole Location

Northing Easting

38896.69 40276.04

40199.22

BH-1

BH-2

BH-3

BH-4

22

APPENDIX ‐ CBOREHOLE LOG, GEOLOGICA CROSS SECTION & WATER

STANDPIPE AND WATER LEVEL READING

BOREHOLE LOG

BORELOG

23

BORELOGBORELOGBORELOGBORELOGBORELOG

24

BORELOGBORELOGBORELOGBORELOGBORELOG

25

BORELOG

26

BORELOGBORELOGBORELOGBORELOGBORELOGBORELOG

27


28

BORELOG

29


30


31

BORELOG

32


33


34

GEOLOGICAL CROSS SECTION

VERTICAL SCALE -

HORIZONTAL SCALE -

Drawn By:

Checked By:

Date:

Date:1:200

1:400

CROSS SECTION : BH-1, BH-2, BH-3 & BH-4

OLD ALLUVIUM

WATER STANDPIPE INSTALLATION &

WATER LEVEL READING

CLIENT Housing and Development Board INSTRUMENT NO. WSP1

BOREHOLE NO. BH-4

REDUCE LEVEL 115.017 m RL

TOP OF PIPE LEVEL 115.367 m RL

LOCATION TAMPINES STREET 62 DATE INSTALLED 9-Sep-19

Date Ground Top of Pipe Depth of Ground Water Remarks SKETCH OF WATER STANDPIPE

(dd-mmm-yy) Level Level Water Level (not to scale)(m RL) (m RL) (m BGL) (m RL)

12-Sep-19 115.017 115.367 3.500 111.867 Initial

14-Sep-19 115.017 115.367 3.600 111.767 Ground Level

17-Sep-19 115.017 115.367 3.800 111.567

21-Sep-19 115.017 115.367 3.700 111.667

3.13 m bgl

3.33 m bgl

10.00 m bglBottom Cap

PROJECT SOIL INVESTIGATION WORKS AT TAMPINES STREET 62

WATER STAND PIPE

GROUND WATER LEVEL MONITORING DATA AND GRAPH

110.00

112.00

114.00

116.00

118.00

10

-Se

p-1

9

12

-Se

p-1

9

14

-Se

p-1

9

16

-Se

p-1

9

18

-Se

p-1

9

20

-Se

p-1

9

22

-Se

p-1

9

24

-Se

p-1

9

Gro

un

d W

ate

r L

evel

(m R

L)

Date

Ground Water Level Monitoring

Ground Level 115.017mRL

PVC Pipe50mm diameter

Compacted Sealof Local Soil

Top Cap

50mm dia.Perforated PVC pipeWrapped all round with Green Nylon Net

Graded FilterMateral of Clean Sand and Gravels Mix

:

:

:

:

:

:

:

:

100 diameter Borehole

Graded Filter Material Of Clean Sand Gravels Mix

5mm Hole Staggered At 100mm (Both Direction)

APPENDIX ‐ DLABORATORY TEST RESULTS

37

38

39

APPENDIX ‐ E

SPT SAMPLE PHOTOGRAPHS

`

Client :

Project : SOIL INEVSTIGATION WORKS AT TAMPINES STREET 62

SPT Photograph

BH-1 SPT 1 to 16

BH-2 SPT 1 to 15

HOUSING & DEVELOPMENT BOARD

40

`

Client :

Project :

HOUSING & DEVELOPMENT BOARD

SOIL INEVSTIGATION WORKS AT TAMPINES STREET 62

BH-3 SPT 1 to 15

BH-4 SPT 1 to 14

SPT Photograph

41

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