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By Ir. Dr. Gue See Sew & Ir. Chow Chee Menghttp://www.gnpgeo.com.myG&P Geotechnics Sdn Bhd ( www.gnpgroup.com.my) (www.gnpgroup.com.my)

G&P Geotechnics Sdn Bhd ( www.gnpgroup.com.my) (www.gnpgroup.com.my)

CONTENTS INTRODUCTION OBJECTIVES DESK STUDY SITE RECONNAISSANCE METHODS OF GROUND INVESTIGATION FIELD TEST AND SAMPLING PLANNING OF GROUND INVESTIGATION SPECIFICATIONS SUPERVISION G&P Geotechnics Sdn Bhd Quality Services - Our Commitment

INTRODUCTIONGuidance notes to engineers on the practical aspect of site investigation

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OBJECTIVESProvide adequate information for - Site assessment, safe and economical designs - Foresee construction difficulties. - Choice of site and layout arrangement.

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Scar

SITE RECONNAISSANCE Confirm and obtain additional information. Examine adjacent and nearby development. Compare the surface features and topography with data obtainable in the desk study. Locate and study the outcrops, previous slips. G&P Geotechnics Sdn Bhd Quality Services - Our Commitment

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METHODS OF GROUND INVESTIGATION

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BOREHOLES Refer to MS2038 Includes boring, sampling, in-situ testing and water table observation. Drill through soils and core through rocks. Two commonly used methods: a) Rotary drilling method b) Rotary wash boring Rock Coring G&P Geotechnics Sdn Bhd Quality Services - Our Commitment

Care in Boreholes Levels and coordinates Samplers in good condition, clean & greased Samplers sealed, labelled & stored

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Sizes of commonly-used Core barrels, Casings and Drill Rods Used

Typical Rotary Drilling Rig

Sampling in Boreholes Disturbed Samples - Split spoon samples from SPT Undisturbed Samples - Mazier Sampler

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Mazier Sampler- Three-tube core-barrels containing detachable liners within the inner barrel. - Suitable for stiffer soil stratum.

Care in Sampling

Groundwater Water level should be taken daily during SI (particularly in the morning). Piezometer should be used for accurate and longer time measurement. Good practice : Allow the ground water drop to original level

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Boreholes with Standpipe Piezometers

Lockable Cap to prevent vandalism Bright Color (Red + White) to prevent vehicle knocking into it.

Borehole Number Clearly Marked on Concrete

4m

Standard Penetration Test (SPT) According to MS 1056 Hammer weight = 65kg Drop height = 760mm Total penetration is 450mm and the number of blows for the last 300mm is the SPT N value. Care - depth of test vs casing L *site supervisionQuality Services - Our Commitment

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Equipment for SPT

PLANNING OF GROUND INVESTIGATION

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S.I. In Grid PatternNot Recommended

(Total = 32 nos)

Proposed SI

(Total = 32 nos)

Typical Cross-Section

Ground Level Hard Material Level

Very Hard Material Level Bedrock Level

Groundwater Level

CROSS SECTIONBH BH

EXISTING GROUND LEVEL

C1, 1

BH

2, 2 r C T aye dW L e y ey erch P Cla

Seepage

C3, 3

Water Table

Selection of Ground Investigation Methods

Slope and cut areas - use Boreholes - SPT and Mazier samples for triaxial tests - Piezometer

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Depth of Investigation

Foundation Design

Stability Analysis

Laboratory Testa) ClassificationSieve Analysis Clay/Silt Atterberg Limits Moisture Content Unit Weight Specific Gravity

c) Compaction Fill

d) ChemicalSO4 CI Ph Resistivity Redox Potential

b) Shear StrengthEffective- CIU - CID

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G&P- Form6 (Rev3)

G&P GEOTECHNICS SDN. BHD. (Geotechnical Consultants) LABORATORY TEST SCHEDULEProject No : .. Lab. Schedule No. .. Requested by : Rev iewed by : ...CONSOLIDAT ION Std. Rapid S.S. TRIAXIAL CIU UU UCTORGA NI C CONTE NT

Date : .. Date : CH EMICAL ANALYSIS PHSULPH ATE CONTE NT CHLORIDE CONTE NT

Project : .. Direct She ar Box SIEVE ANALYSIS Mech. Hydro.

BOREHOLE

SAM PLE NO.

DEPTH m

M/C

A.L.

B.D .

S.G.

T OT AL Note : 1) C IU

Requested Performed

I sotro pic Conso lidat ed Undra ined Tr iaxial Te st with por e pressur e measurements Use 70mm diameter samp le (i.e. u ntr immed Mazier sample) Sample should n ot have side filter dur ing consolida tion Shearing str ain sho uld be calculat ed using Cv values ca lculated dur in g consolidatio n stage. M ulti- stage testing not allowe d P- Q Stress Pat h Plotting sh all be submitted. 2) F or CIU T ests, stress path an d other relevant da ta shall be submitted in Ha rd Copy (Plots and Tabu lated Data) and Soft Copy (Co mpu ter files data). Cell confinin g pr essure of 0.5 v , 1.0v, 2.0v shall be ad opted for t he CIU test, whe re v is the total vertical in-sit u stress. 3) U U Unconsolidated U ndr ained Test (at tota l overbu rd en p re ssur e of the sample) 4) UCT Unconfined Com pr ession Test ( untrimm ed sam ple)

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5) To determin e Cv from Consolidation Tests :Use Squar e-Root Time Method to deter mine d0 . Then use Log-Time Met hod to dete rmine d10 0 6) Direct shear box test - Three (3) r econ stituted specimens (60mm x 60m m x 20 mm thick) sh all be used. - Applied nor mal stress pressure of 0.5 v, 1.0v , 2.0v shall be adopte d for th e she ar box test, where v is the total vertica l in- situ stress. 7) All specimens for tr iaxial or consolidation tests shall be obtained from center of th e r ecovere d samp les in UD sam pler. 8) 2 moisture content te sts shall be car ried out on soil immediately besides the specimens ret ained for tria xial or co nsolidation tests. 9) Bulk densit y, particle size distribut ion and Atterb er g Limit te sts shall b e carried out o n every specimen afte r the tr iaxial or consolidation tests.

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Special Attention

Triaxial Compression Test No/Minimum Trimming No Side Drains No Multistage

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SITE SUPERVISION Full time Engineering Geologists, Engineers or experienced Technicians Briefing (Supervision Checklist) Communication Checklist (http://www.gnpgeo.com.my/RnD_spec_checklist_checklist.asp)

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CONCLUSIONS1. You pay for soil investigation whether you carry out or not. In fact you eventually pay more without a soil investigation.

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CONCLUSIONSPrincipal conclusions:1. Delay and escalating construction costs are due to inadequate site investigation Consequences of inadequate SI is not only severe during design and construction stage but even more serious for fulllife costing

2.

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CONCLUSIONS (cont)2. You must know - why you wanted them - where they are to be carried out - how they should be done

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CONCLUSIONS (cont)3. Use proper specifications 4. Full time supervision 5. Ensure QA/QC system.

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CONTENTS INTRODUCTION OBJECTIVES SCOPE INTERPRETATION- JKR PROBE - SPT

DESIGN PARAMETERS LABORATORY TESTS G&P Geotechnics Sdn Bhd Quality Services - Our Commitment

INTRODUCTION NEED- Neglected topic; only briefly covered in universities - Danger of using results directly without interpretation - Decision on choice of values for soil parameters

SCOPE- Common tests only

PROCESSES- Specifications, Supervision, Presentation & Interpretation G&P Geotechnics Sdn Bhd Quality Services - Our Commitment

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Proton Iswara

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OBJECTIVES

Illustrate the importance of interpretation Show methods of compiling results and recognising errors

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SCOPE- Common field and laboratory tests

FIELD TESTS- JKR/ Mackintosh probe - SPT (Standard Penetration Test)

LABORATORY TESTS- Unconfined compression - Triaxial Test (CIU with pore pressure measurement & CD)

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