spec - 21 august 2013_220813

8/13/2019 SPEC - 21 August 2013_220813

1/76

ANNEX A SPECIFICATION

8/13/2019 SPEC - 21 August 2013_220813

2/76

Sibundong Hydropower Project | PFS Review Report | Revision No. | Sep 2013 Page | i

TABLE OF CONTENTS

1 GENERAL ............................................................................................................... 11.1 Scope of Work.......................................................................................................... 11.2 Site Access .............................................................................................................. 11.3 Temporary Access ................................................................................................... 11.4 MobilizationDemobilization ................................................................................... 21.5 Safety and Convenience of the Public ...................................................................... 21.6 Codes of Practice ..................................................................................................... 21.7 Contractors Professional Attendance on Site .......................................................... 21.8 Temporary Building and Sanitary Accommodation ................................................... 21.9 Storage Facilities ...................................................................................................... 31.10 Workmen Accommodation ....................................................................................... 31.11 Watching and Lighting .............................................................................................. 31.12 Water and Electricity Supplies .................................................................................. 31.13 Discharge of Water .................................................................................................. 31.14 Damage to and Clearing of Sites .............................................................................. 31.15 Clearance of Site on Completion .............................................................................. 41.16 Facilities for Testing by the Supervising Geologist ................................................... 41.17 Facilities for Other Contractors ................................................................................. 42 SITE INVESTIGATIONS - GENERAL ...................................................................... 52.1 Equipment ................................................................................................................ 52.2 Positions of Investigations and Leveling ................................................................... 52.3 Measurements ......................................................................................................... 52.4 System Internationale Units...................................................................................... 53 DRILLING ................................................................................................................ 63.1 Equipment ................................................................................................................ 63.2 Priority ...................................................................................................................... 63.3 Positioning of Drill rigs .............................................................................................. 63.4 Advance of Drillholes................................................................................................ 63.5 Setting-Out ............................................................................................................... 73.6 Identification and Numbering .................................................................................... 73.7 Depth of Drillholes .................................................................................................... 73.8 Drilling Obstruction ................................................................................................... 73.9 Abandoned Drillholes ............................................................................................... 73.10 Termination of Drillholes ........................................................................................... 73.11 Measurement ........................................................................................................... 83.12 Payment ................................................................................................................... 8

8/13/2019 SPEC - 21 August 2013_220813

3/76

Sibundong Hydropower Project | PFS Review Report | Revision No. | Sep 2013 Page | ii

4 BORING AND SAMPLING IN OVERBURDEN ........................................................ 94.1 Drilling in Overburden............................................................................................... 94.2 Disturbed Samples ................................................................................................... 94.3 Undisturbed Samples ............................................................................................... 94.4 Mazier Samples ..................................................................................................... 104.5 Measurement ......................................................................................................... 104.6 Payment ................................................................................................................. 115 DRILLING AND SAMPLING IN ROCK .................................................................. 125.1 Equipment .............................................................................................................. 125.2 Reaming Casing and Grouting ............................................................................... 125.3 Angle Drilling .......................................................................................................... 125.4 Boxing and Storage of Core ................................................................................... 125.5 Measurement ......................................................................................................... 135.6 Payment ................................................................................................................. 136 HAND HELD DRILLING ........................................................................................ 146.1 Equipment .............................................................................................................. 146.2 Priority .................................................................................................................... 146.3 Positioning of the Hand Held Drill ........................................................................... 146.4 Procedure .............................................................................................................. 146.5 Measurement ......................................................................................................... 156.6 Payment ................................................................................................................. 157 GROUNDWATER .................................................................................................. 167.1 Groundwater Observations .................................................................................... 167.2 Measurements ....................................................................................................... 167.3 Payment ................................................................................................................. 168 TEST PITS AND AUGER BORING ....................................................................... 178.1 TEST PITS ............................................................................................................. 17

8.1.1 General .................................................................................................... 178.1.2 Size .......................................................................................................... 178.1.3 Safety ....................................................................................................... 178.1.4 Backfilling ................................................................................................. 178.1.5 Logging .................................................................................................... 178.1.6 Disturbed Samples ................................................................................... 178.1.7 Undisturbed Block Samples ...................................................................... 188.1.8 Measurement ........................................................................................... 188.1.9 Payment ................................................................................................... 18

8.2 Power Auger Boring ............................................................................................... 188.2.1 General .................................................................................................... 188.2.2 Measurement ........................................................................................... 188.2.3 Payment ................................................................................................... 18

8/13/2019 SPEC - 21 August 2013_220813

4/76

Sibundong Hydropower Project | PFS Review Report | Revision No. | Sep 2013 Page | iii

9 INSITU TESTING ................................................................................................... 199.1 Standard Penetration Test ..................................................................................... 19

9.1.1 General .................................................................................................... 199.1.2 Equipment ................................................................................................ 199.1.3 Test Method ............................................................................................. 199.1.4 Correction of Results ................................................................................ 199.1.5 Measurement ........................................................................................... 209.1.6 Payment ................................................................................................... 20

9.2 Single Packer Field Permeability Test .................................................................... 209.2.1 General .................................................................................................... 209.2.2 Equipment ................................................................................................ 209.2.3 Test Procedure ......................................................................................... 219.2.4 Measurement ........................................................................................... 219.2.5 Payment ................................................................................................... 22

9.3 Constant Head Permeability Tests ......................................................................... 229.3.1 General .................................................................................................... 229.3.2 Equipment ................................................................................................ 229.3.3 Test Method ............................................................................................. 229.3.4 Test Results ............................................................................................. 229.3.5 Measurement ........................................................................................... 229.3.6 Payment ................................................................................................... 23

9.4 Variable Head Permeability Tests .......................................................................... 239.4.1 General .................................................................................................... 239.4.2 Equipment ................................................................................................ 239.4.3 Test Method ............................................................................................. 239.4.4 Test Results ............................................................................................. 239.4.5 Measurement ........................................................................................... 239.4.6 Payment ................................................................................................... 24

9.5 Pressuremeter Tests .............................................................................................. 249.5.1 General .................................................................................................... 249.5.2 Equipment ................................................................................................ 249.5.3 Testing Procedure .................................................................................... 249.5.4 Measurement ........................................................................................... 259.5.5 Payment ................................................................................................... 259.5.6 General .................................................................................................... 259.5.7 Equipment ................................................................................................ 259.5.8 Test Method ............................................................................................. 259.5.9 Measurement ........................................................................................... 259.5.10 Payment ................................................................................................... 26

9.6 Shear Vane Tests .................................................................................................. 269.6.1 General .................................................................................................... 269.6.2 Equipment ................................................................................................ 269.6.3 Test Procedure ......................................................................................... 269.6.4 Measurement ........................................................................................... 269.6.5 Payment ................................................................................................... 26

8/13/2019 SPEC - 21 August 2013_220813

5/76

Sibundong Hydropower Project | PFS Review Report | Revision No. | Sep 2013 Page | iv

10 LABORATORY TESTING...................................................................................... 2710.1 GENERAL .............................................................................................................. 2710.2 LABORATORY SOIL TESTING ............................................................................. 2710.3 TESTS ON ROCK MATERIALS ............................................................................. 2811 TEST METHODS ................................................................................................... 2911.1 Oedometer Consolidation Tests ............................................................................. 2911.2 Unconsolidated Undrained Triaxial Tests (Undisturbed Specimen) ........................ 2911.3 Unconsolidated Undrained Triaxial Test (Remoulded Specimen) ........................... 2911.4 Consolidated Undrained Triaxial Tests With Pore Pressure Measurement

(Undisturbed Specimen) ......................................................................................... 3011.5 Consolidated Undrained Triaxial Test With Pore Pressure Measurement

(Remoulded Specimen) .......................................................................................... 3011.6 Pore Pressure Dissipation Test .............................................................................. 3011.7 Compaction Tests .................................................................................................. 3111.8 Point LoadDiametrial & Axial Test ...................................................................... 3111.9 Uniaxial Compression Test (Ucs) ........................................................................... 3211.10Measurement ......................................................................................................... 3211.11Payment ................................................................................................................. 3212 RECORDS AND REPORTING .............................................................................. 3312.1 Shift Reports .......................................................................................................... 3312.2 Photographs ........................................................................................................... 3412.3

Exploration Logs .................................................................................................... 34

12.4 Clarity Of Records .................................................................................................. 3412.5 Interim Laboratory Test Results ............................................................................. 3412.6 Progress Reports ................................................................................................... 3512.7 Final Report ........................................................................................................... 3512.8 Property Of Employer ............................................................................................. 3512.9 Measurement And Payment ................................................................................... 3512.10Daywork ................................................................................................................. 3612.11

Idle Time ................................................................................................................ 36

13 ELECTRICAL RESISTIVITY TOMOGRAPHY (ERT) ............................................. 3713.1 Scope ..................................................................................................................... 3713.2 Objectives .............................................................................................................. 3713.3 Equipment And Personnel ...................................................................................... 3713.4 Personnel ............................................................................................................... 3713.5 Source Of Power .................................................................................................... 3713.6 High Impedance Voltmeter ..................................................................................... 3813.7 Electrodes .............................................................................................................. 3813.8 Cables .................................................................................................................... 38

8/13/2019 SPEC - 21 August 2013_220813

6/76

Sibundong Hydropower Project | PFS Review Report | Revision No. | Sep 2013 Page | v

13.8.1 Signal Enhancement ................................................................................ 3813.8.2 Analytical Software ................................................................................... 38

13.9 Limitations And Interferences ................................................................................. 3813.10Recommended Electrodes Arrays .......................................................................... 3913.11The Wenner Array .................................................................................................. 39

13.11.1The Schlumberger Array ........................................................................... 40

13.11.2 The Dipole-Dipole Array ........................................................................... 40

13.12Measurements And Interpretation .......................................................................... 4113.12.1 Vertical Electrical Sounding (VES) ............................................................ 4113.12.2 Horizontal Profiling ................................................................................... 4113.12.3 Combined Profiling ................................................................................... 42

13.13Procedure .............................................................................................................. 4213.14Quality Control ....................................................................................................... 4313.15Report And Presentation ........................................................................................ 4313.16Safety ..................................................................................................................... 44

13.16.1 Shock Hazard ........................................................................................... 4413.16.2 Electrical Storms....................................................................................... 44

13.17Measurement ......................................................................................................... 4413.18Payment ................................................................................................................. 45APPENDICES

APPENDIX A DESCRIPTION OF SOIL AND ROCK

APPENDIX B PRODUCTION OF CORE BORE LOG

APPENDIX C FIELD TEMPLATES

8/13/2019 SPEC - 21 August 2013_220813

7/76

Sibundong Hydropower Project | PFS Review Report | Revision No. | Sep 2013 Page | 1

1 GENERAL

This specification describes the requirements of a geotechnical site investigation to be carriedout at the location/s given in the attached schedules.

This site investigation specification is intended to provide guidance to geologists andgeotechnical engineer and to establish the processes, procedures, and methods for conductingand documenting field investigation of high quality in accordance with standard industrypractice.

1.1 Scope of Work

The aim of site investigation is to obtain data representative of the ground conditions andrelevant to the project site. It should also provide data which relate to ground conditions beyondthe immediate vicinity of the site where soil, rock, groundwater, and existing or future structuresmay affect or be affected by works.

The main objectives of the site investigation are as follows: Assessment of general suitability of the site and neighborhood for the proposed works,

from a geological and geotechnical point of view.

Provision of suitable geotechnical data for all aspects of an economic, safe and reliabledesign of foundations, earthworks and temporary works, including assessment of theeffects of any previous uses of the site.

Assessment of the problems and constraints associated with the construction of theworks arising from the soil or groundwater conditions, including temporary works,excavation, trafficability and drainage.

Assessment of the quantity, quality and ease of extraction of construction materials

suitable for the works, where relevant.

Consideration of changes in the stability, drainage or other geotechnical aspects of thesite and the surrounding ground and buildings, which might be initiated by theconstruction works.

Comparison of construction by alternative methods or at alternative sites.

Occasionally, a ground investigation may be carried out for the following reasons:

o Assessment of the stability of existing structures, works or natural features.

o Investigation of a foundation or natural ground failure, including excessivesettlement, heave, lateral deformation or instability of slopes.

1.2 Site Access

The site is not easily accessible. In order to reach the project site it is required to travel by car tothe town of Manalu. From there the road has been eroded and landslides have taken awayparts of the access tracks. Motorised access is not possible by road.

None of the sites can be accessed directly from the main road, trekking on steep and vegetatedslopes are required to reach the different sites. The contractor will be required to constructtracks for itsown purposes.

1.3 Temporary Access

The Contractor shall provide all temporary roads and gangways required for the execution of theWorks. He shall provide at all times during the progress of the Works, proper means of access

8/13/2019 SPEC - 21 August 2013_220813

8/76


with ladders, gangways, vehicles etc. and the necessary attendance for inspection of the Worksby the Field Supervision Geologist or the SMEC representatives as directed.

The cost of carrying out all such work shall be deemed to be included in the Contract Rates.

1.4 MobilizationDemobilization

The Contractor shall mobilize all personnel, drilling equipment, materials and supplies requiredto execute the Works and shall set up his equipment at the site ready in every respect foroperation in accordance with the Field Supervision Geologist representativesinstruction.

Upon the completion of the Works, the Contractor shall remove all his drilling equipment andinstallations from the worksites. He shall also remove any remnants of materials that were notused, any waste materials any rejected materials or stores. In general, the Contractor shallleave the work sites in a state of order and cleanliness to the satisfaction of the FieldSupervision Geologists demand.

Payment for mobilization and demobilization of all drilling plant, including all related equipment,to the site will be made at the applicable lump sum tendered therefore in the priced Bill of

Quantities.Payment for movement of drilling plant, percussion (cable-tool) rig and power auger rig andequipment to each drill hole location will be made at the applicable rate tendered therefore inthe priced Bill of Quantities

1.5 Safety and Convenience of the Public

During the execution of the Works, the Contractor shall be responsible for ensuring that hisvehicles, plant, equipment and staff do not cause interference with the operations of other usersof roads, logging tracks, footpaths and waterways.

The Contractor shall at his own expense provide and maintain at site all lights, warning signs,

guards, fencing, etc. for the safety and convenience of the public.

1.6 Codes of Practice

Unless otherwise specified, the works included in the site investigation shall be carried out inaccordance with B.S. 5930 Code of Practice for Site Investigations, the B.S. 1377 Methods ofTest for Soils for Civil Engineering Purpose, with the current Australian Standards AS1726-1193: "Geotechnical Site Investigations", A.S. 1289 Methods of Testing Soils for EngineeringPurposes and Suggested Methods for Rock Testing by International Society for RockMechanics. Equivalent Standards can be used by mutual agreement with the Engineer.

The descriptions of soil and rock shall be as defined inAppendix A.

1.7 Contractors Professional Attendance on Site

The Contractor shall provide an Engineering Geologist qualified with a degree in geology froman approved University. The engineering geologist shall have at least five (5) years experienceon site on similar works and shall be subject to approval by the Client, which approval may bewithdrawn at any time. The engineering geologist shall be on site full time and shall beresponsible for the technical direction and output of the whole of the investigation. Theengineering geologists duties shall include geological logging of drill cores and test pits and thepreparation of investigation records and Final Fieldwork Reports in English.

1.8 Temporary Building and Sanitary Accommodation

The Contractor shall provide, erect, maintain and subsequently remove such temporarybuildings, and proper and adequate conveniences for the use of his workmen to the satisfactionof the Field Supervision Geologist.

8/13/2019 SPEC - 21 August 2013_220813

9/76


The Contractor shall be responsible for keeping such areas in a clean and sanitary conditionand on completion of the Works shall clear the areas and reinstate the ground, all to thesatisfaction of the Field Supervision Geologist.

The cost of carrying out all such work shall be deemed to be included in the Contract Rates.

1.9 Storage Facilities

The Contractor shall provide proper facilities for the storage and protection of soil and rocksamples. The Contractor shall be responsible for storing the soil and rock samples at the sitecamp at the end of each days work. Rock samples in core boxes shall be stored in a placeprotected from rain, direct sunlight, wind and surface running water.

1.10 Workmen Accommodation

The Contractor shall be responsible for his workers accommodation. No area on the site or anyother location will be provided by the Employer for accommodation.

1.11 Watching and LightingThe Contractor shall in connection with the Works provide and maintain at his own cost alllights, guards, fencing and watching when and where necessary or by any competent statutorybody or other authority for the protection of the Works or for the safety and convenience of thepublic or others.

1.12 Water and Electricity Supplies

The Contractor shall at his own expense install, operate and maintain throughout the period ofexecution of the Works all such water and electricity supplies necessary for the drilling sites,and remove all the installations on completion of the Works.

The cost incurred in providing the above services shall be deemed to be included in theContract Rates.

1.13 Discharge of Water

The Contractor shall make adequate provisions for the discharge of any water from the Worksto the satisfaction of the Field Supervision Geologist, and to the satisfaction of any personhaving rights over the lands and water courses over or into which water is discharged. TheContractor shall by means of intercepting grips, drains, bunds or covers take all reasonableprecautions to prevent surface or other water from entering any part of the Works and shallreinstate the areas as approved by the Field Supervision Geologist on completion of the Works.

1.14 Damage to and Clearing of Sites

The Contractor shall be solely responsible for any damage caused by his activities within oroutside the areas of the sites.

Clearing of vegetation for gaining access to locations of subsurface exploration shall bein accordance with the proposals submitted by the Contractor with his tender andapproved in the Letter of Acceptance. The limits of clearing shall be as directed by theField Supervision Geologist.

The Contractor shall be responsible to obtain clearance and approval from therespective government authority. Necessary fee as deemed necessary to be included inthe cost proposal. No separate payment will be made.

8/13/2019 SPEC - 21 August 2013_220813

10/76


1.15 Clearance of Site on Completion

As soon as the investigation work is completed, all test pits shall be backfilled and drillholesshall be capped or sealed to the satisfaction of the Field Supervision Geologist. On completion,the Contractor shall remove from site all plant, surplus materials, temporary works and rubbishof any kind, and leave the Site and Works clean and tidy to the satisfaction of the Field

Supervision Geologist.

1.16 Facilities for Testing by the Supervising Geologist

Independent sampling and testing may be carried out by the supervising geologist throughoutthe Contract period and for this purpose the Contractor shall grant the use of the Contractorsequipment, supply materials and provide facilities for the supervising geologist.

The cost for providing facilities for testing by the Field Supervision Geologist shall be deemed tobe included in the Contract Rates.

1.17 Facilities for Other Contractors

The Contractor shall in accordance with the requirements of the Client, afford all reasonablefacilities for any other contractors employed by the Employer and their workmen and for theworkmen of the Employer and of any other properly authorized authorities on or near the Site ofany work not included in the Contract or of any Contract which the Employer may enter inconnection with or ancillary to the Works.

1.18 Radio Communication/Amenities/Facilities for Supervising Geologist

The Contractor shall supply, for the duration of the contract period, one mobile radio set,together with battery recharge facilities, for the use of the Supervising Geologist to communicatewith the Contractors Site personnel. The radio set shall be maintained and insured by theContractor. On completion of the Contract, the radio set will be returned to the Contractor (item1.19).

8/13/2019 SPEC - 21 August 2013_220813

11/76


2 SITE INVESTIGATIONS - GENERAL

2.1 Equipment

The Field Supervision Geologist should inspect all equipment mobilized to the site by thecontractor to ascertain whether the equipment is as specified in accordance with thecontractors approved work plan and suitable in condition, quantity, and type to perform thework.

2.2 Positions of Investigations and Leveling

The anticipated types of investigations for each site are shown on the attached InvestigationSchedule. This Schedule is tentative only and significant variations may occur. It is notguaranteed that any or all of the investigations will be requested. The tentative locations ofsome of the investigations are marked on the sketch plans for each site.

The Field Supervision Geologist will indicate on site the exact positions of investigations.He/She will direct in what order the investigations are to be performed. The positions will beindicated by the Field Supervision Geologist in sufficient time to allow preparatory work to becompleted.

Investigation locations can be marked initially using GPS or compass, tape, altimeter or otherapproximate methods either by the Contractor or the Field Supervision Geologist. A final surveycheck must be done while drilling or after the investigation has been completed. Survey mustinclude Easting, Northing and elevation of the drillhole collar in UTM units.

Investigations shall be performed within 2m of the pegged site. The level of the ground surfaceat each site will be determined by the Field Supervision Geologist.

Where borings are made from excavations, the ground level shall be deemed to be that point onthe face, sides or bottom of the excavation, where penetration of the bores commenced.

2.3 Measurements

Except where any description of the work in the Specification, Drawing or Bill of Quantitiesexpressly shows the contrary, measurement shall be made in accordance with the procedureset forth in the latest edition of the Standard Method of Measurement of Civil EngineeringQuantities published by the Institution of Civil Engineers.

The Field Supervision Geologist is responsible for confirming all locations, lengths, depth andmeasurements reported by the Contractor are correct and also to ensure that all core boxes,samples, logs, forms, and reports are properly labeled.

2.4 System Internationale Units

Only S.I. (System Internationale) units shall be used during the currency of the contract and inreports. All measurements shall be in metric units.

8/13/2019 SPEC - 21 August 2013_220813

12/76


3 DRILLING

3.1 EquipmentThe Contractor shall advance the drill holes using rotary hydraulic feed rigs with a drilling headcapable of accepting `N size drill rods and capable of driving rotary cutting tools tipped withdiamonds or tungsten carbide. The rigs shall be capable of drilling vertical and angled holes to amaximum depth of 50-70 m. The rigs have to be equipped in order to work with wirelinetechniques.

Core recovery equipment shall be triple tube retractable swivel-type core barrels.

The size of bits, core barrels and casing shall conform to BS 4019 (Rotary core drillingequipment) or as otherwise agreed by the Field Supervision Geologist.

3.2 Priority

The drilling of holes for engineering structures shall receive priority over the drilling of holes formaterial borrow areas.

The priority of all the drillholes will be indicated and confirmed by the Field SupervisionGeologist on site.

3.3 Positioning of Drill rigs

The Contractor shall provide such temporary drilling platforms as may be necessary to keep thedrilling rig stable and level when putting down drillholes on sloping ground.

3.4 Advance of DrillholesThe Contractor shall advance the drillholes by using rotary drilling methods with casing of notless than `N size.Subject to the approval of the Field Supervision Geologist drilling withoutcasing will be permitted provided that there is no collapse of the wall of the uncased drillhole. Acollapse is considered to have occurred when, in the opinion of the Field Supervision Geologistthere is a mingling of soil or rock from different depths inside the drillhole. The size of the casedor uncased drillhole shall be such that the requirements described in the following clauses inrespect of sampling, ground water observation, field tests and records are satisfied. TheContractor shall be solely responsible for ensuring that the casings are inserted in such amanner as to render them recoverable and the Contractor shall have no claim upon theEmployer for damage, loss or delay caused by difficulty or failure to recover a casing.

In the event of the collapse of the walls of the drillhole, other methods of stabilising the walls ofthe uncased drillhole, besides casing, may be allowed subject to the prior approval of the FieldSupervision Geologist.

Drilling shall be carried out in such a manner and using such sizes of bits, that the maximumcore is recovered. This requires close surveillance of wash water, drilling pressures, lengths ofruns and all other factors relevant to the nature of the material drilled. The core barrel shall bewithdrawn and the core removed as often as may be necessary to secure the maximumpossible amount of core. Face discharge bits (as shown in BS 4019) shall be used unlessotherwise agreed by the Field Supervision Geologist. Dry drilling methods may be directed bythe Field Supervision Geologist. A drag bit, or rock roller bit may be used but only with the priorpermission of the Field Supervision Geologist.

Where instructed by the Field Supervision Geologist, the Contractor shall increase the size of adrillhole by reaming. The larger casing shall be set concentric with the existing hole and shall besunk parallel with it.

8/13/2019 SPEC - 21 August 2013_220813

13/76


3.5 Setting-Out

Setting-out shall be carried out by the Field Supervision Geologist.

3.6 Identification and Numbering

The system to be used for identification numbering of field exploration will require the allocationof unique numbers for features, investigations, samples and tests, as described below.

The Field Supervision Geologist will allocate the investigation number, excavation type, samplenumber and sample type or test number and test type.

The identification numbering sequence and abbreviations for each investigation will be:

for Cored Boreholes: BH-SBG-FS-01 etc.

for Auger Boreholes: BA-SBG-FS-01 etc.

for single Standard Penetration Tests: SPT-SBG-FS-01 etc.

for DCP: DCP-SBG-FS-01 etc.

for Test Pits: TP-SBG-FS-01 etc.

for hand-held drill Boreholes: HS-SBG-FS-01 etc.

for Seismic Refraction Lines: SR-SBG-FS-01 etc.

for Electric Resistivity Lines: ER-SBG-FS-01 etc.

3.7 Depth of Drillholes

The depths, orientation, number and locations of drillholes are provisional. The FieldSupervision Geologist may vary the quantities.

3.8 Drilling Obstruction

It shall be the Contractors responsibility when boulders or other obstacles are encountered tocarry the drilling through or past such obstacles or, if directed, to core the obstacle to determineits size and character.

3.9 Abandoned Drillholes

Except with the specific permission of the Field Supervision Geologist, the Contractor shall notabandon or complete a drilling or remove any casing or drilling equipment without first giving theField Supervision Geologist the opportunity of obtaining the position and depth of the drillholebefore abandonment or completion, and any other information which the Field Supervision

Geologist may require. No allowance or payment whatsoever will be made for any drillingabandoned or completed without compliance with those stipulations. In addition, in order toreceive consideration for payment for abandoned drillholes, the Contractor shall furnish theField Supervision Geologist with complete records and samples for the depths penetrated in themanner prescribed for completed drillholes.

3.10 Termination of Drillholes

The termination of each drillhole shall be decided by the Field Supervision Geologist. TheContractor shall inform the Field Supervision Geologist immediately on reaching the depthdirected by the Field Supervision Geologist.

8/13/2019 SPEC - 21 August 2013_220813

14/76


3.11 Measurement

Measurement for payment, for moving drilling plant from one position to the next includingestablishment of temporary drilling platforms and setting up will be made of the number ofmoves directed by the Field Supervision Geologist.

Measurement for payment, of casing left in drillholes at the direction of the Field SupervisionGeologist will be made of the actual length of casing left in place. Measurement will not bemade for casing that is left in drillholes without the direction of the Field Supervision Geologist.

3.12 Payment

Payment for moving drilling plant from one position to the next including setting up will be madeat the rate per move tendered therefore in the priced Bill of Quantities

Payment for casing left in drillholes at the direction of the Field Supervision Geologist will bemade at the applicable rate per linear metre items tendered therefore in the priced Bill ofQuantities (item 2.1.1 and 2.1.2).

8/13/2019 SPEC - 21 August 2013_220813

15/76


4 BORING AND SAMPLING IN OVERBURDEN

4.1 Drilling in Overburden

Boring in overburden (or other than rock namely alluvium, slopewash and residual soil) shallbe by wash boring by rotary drilling using a solid roller, button or drag bit at the end of the drillrods, as directed by the Field Supervision Geologist.

4.2 Disturbed Samples

Disturbed samples with a mass of not less than 1 kg shall be taken by an approved technique atintervals of 3.5 m, unless otherwise directed by the Field Supervision Geologist.

Disturbed samples shall be sealed in thick polythene bags or screw-top jars. The bags or jarsshall be marked and labelled with the job number, drillhole, sample depth and sample numberand blow count if applicable. The samples shall be stored at the drillers campat the end of

each days work and when directed by the Field Supervision Geologist transported to thedesignated laboratory.

4.3 Undisturbed Samples

When directed by the Field Supervision Geologist, undisturbed tube samples shall be takenusing thin-walled open drive or piston samplers, as appropriate to the site conditions and shallbe taken at an interval of 3.0 m unless otherwise directed by the Field Supervision Geologist.The sampling equipment shall be approved by the Field Supervision Geologist for the particularsite conditions.

Before sampling is commenced, the bottom of the drillhole shall be cleaned out with somesuitable tool to remove all loose material.

Sample tubes must be clean, smooth and rust and dent free with an inside diameter not lessthan 50 mm. The area ratio of the sampler shall not exceed 10 per cent. The cutting edge is to

be machined with a bevel on the outside of the tube which makes an angle not exceeding 5to

the axis of the tube, except that a 45 land not exceeding 0.5 mm in width which will bepermitted right at the cutting edge. The cutting edge must be sharp and free from imperfectionsas would impair the quality of the sample. The tubes shall be lightly oiled with a mineral oilbefore use.

Where open drive samplers are used, ports must be fitted to permit the escape of water or air asthe sampler is driven. It must have some effective form of non-return valve to remove the load ofwater from the top of the sample, thus aiding the safe recovery of the sample. Core catchers are

not permitted.Hammering of sample tubes into the soil is not permitted. Tubes must be either smoothly jackedor, where this is not possible; tubes may be advanced into the soil using an auger core sampler.The drive length shall not exceed the sample tube length less 100 mm and shall be recorded tothe nearest 20 mm. After being driven to the desired depth the sample tube shall be left for 10minutes prior to being rotated a minimum of 5 times and then removed from the drillhole. Theminimum acceptable sample length shall be three sample diameters. Where recovery is lessthan the minimum acceptable sample length, the hole shall be cleaned out and another sampleattempted.

Prior to sealing of the sample against moisture loss, pocket penetrometer and pocket vaneshear tests shall be made at the bottom of the undisturbed samples. The pocket penetrometer

and pocket vane shear shall be of a type approved by the Field Supervision Geologist and thistesting is deemed to have been allowed for in the Contractors rates for undisturbed sampling.All tests shall be recorded in a standard format approved by the Field Supervision Geologist.

8/13/2019 SPEC - 21 August 2013_220813

16/76


Immediately after pocket penetrometer and pocket vane shear testing and materialclassification, the sample shall be sealed using non-shrinking wax or mechanical seals. Thetube shall be tagged and marked with waterproof ink to show the job number, date of sampling,drillhole and sample number together with depth of sampling and recovery ratio. Each sampletube shall have a unique reference number and the word TOP written on its exterior at the endwith the uppermost sample. The samples shall be transported to the laboratory in an approvedbox lined with shock absorbing material. Whilst in the laboratory (and on site) the samples shall

be stored horizontally and rotated 180twice weekly.

4.4 Mazier Samples

Mazier samples of 76 mm diameter and 1.0 m in length shall be taken at locations asdesignated by the Field Supervision Geologist. The following basic rules of operation shall beadhered to in obtaining good quality samples:

the rate of penetration shall be no greater than the speed at which the outer barrel isable to cut; i.e. the downward force shall be a minimum,

the speed of rotation shall be limited to that which will not tear or break the soil sample(generally this will vary from 40 to 125 revolutions per minute)

the extension of the inner barrel shoe beyond the outer barrel cutting teeth depends onthe soil (generally longer for softer soils) and shall be the least amount which will resultin a fully filled inner barrel and which will not cause undercutting or contamination of thesample by drilling fluid,

the core catcher shall not be used unless absolutely necessary to retain the soil.

To effect sample recovery, the sample is cored using standard procedure to about 35 mm to 50mm of the final desired depth, then the drilling fluid is shut off and the coring operationcompleted. This procedure will result in some compaction of the soil and assist in samplerecovery.

The minimum acceptable sample length shall be 500 mm.

After the completion of the drive, the sampler is withdrawn from the hole and extreme care shallbe taken at all times to avoid disturbance. The outer and inner barrel shoes shall be removedwithout jarring the samples. The soil at the ends shall then be removed to a depth of about 50mm, to a smooth flat surface. A wooden filler block, previously waxed, shall be placed inside theliner tube at each end and covered with melted wax. The tube shall be crimped over the woodfillers to hold them in place.

The samples shall be transported to the laboratory in an approved box lined with shockabsorbing material. Whilst in the laboratory (and on site) the samples shall be stored

horizontally and rotated 180twice weekly.

In the laboratory two diametrically opposed cuts (less than 10 mm deep) shall be made alongeach tube using a circular saw or jig saw. The sample shall be carefully split making sure thatthe soil is torn and not cut. One half of the sample shall be placed in a core box measuring 1.05m in length such that 1.0 m of continuous sample is stored in each compartment. Boxing andmarking of samples shall be as for diamond drill core. The other half of the split sample shall beused for pocket penetrometer, shear vane, classification and moisture content tests.

The boxed samples shall be allowed to partially dry to expose the soil structure and shall belogged and photographed in colour. All photographs shall include a standard colour chart toensure correct colour rendition and shall include the drillhole number, box number and depth.

4.5 Measurement

Measurement, for payment, of non-core drilling (washboring) of holes whether cased oruncased in overburden (other than rock) including the taking of disturbed samples and delivery

8/13/2019 SPEC - 21 August 2013_220813

17/76


to the laboratory will be made of the length of the holes drilled at the direction of the FieldSupervision Geologist.

Measurement, for payment of dry drilling of holes in other than rock (over burden) to recovercore between 50 mm and 60 mm diameter including delivery of core into standard boxes will bemade of the length of holes drilled at the direction of the Field Supervision Geologist.

Measurement, for payment, of recovery and sealing of thin walled undisturbed samples,including visual classification, pocket penetrometer testing, pocket, vane shear testing andtransport to the laboratory will be made of the number of acceptable samples recovered andsealed, at the direction of the Field Supervision Geologist.

Measurement, for payment, of Mazier samples will be made of the number of acceptablesamples recovered at the direction of the Field Supervision Geologist.

4.6 Payment

Payment for non-core (wash boring) drilling of vertical or inclined holes in other than rockincluding taking of disturbed samples will be made at the applicable rates per linear metre

tendered therefore in the priced Bill of Quantities (item 2.2).Payment for dry core drilling of vertical or inclined holes in other than rock will be made at theapplicable rates per linear metre tendered therefore in the priced Bill of Quantities (item 2.3).

Payment for recovery and sealing of thin walled U50 undisturbed samples including visualclassification, pocket penetrometer testing, pocket vane shear testing and transport to thelaboratory will be made of the number of samples recovered and sealed at the direction of theField Supervision Geologist, therefore in the priced Bill of Quantities (item 3.3.2).

Payment for Mazier sampling will be made at the rate per sample tendered therefore in thepriced Bill of Quantities (item 2.5). This rate shall be deemed to include sampling, provision ofadequate additive, PVC sample tubes, drilling and sampling, provision of core boxes, rubber

end covers, sample splitting, visual classification, pocket penetrometer and torvane testing andthe provision of colour photographs.

8/13/2019 SPEC - 21 August 2013_220813

18/76


5 DRILLING AND SAMPLING IN ROCK

5.1 Equipment

Unless otherwise approved by the Field Supervision Geologist core drilling shall be carried outusing hydraulic-feed equipment. Side discharge diamond core bits shall be used with a triple-tube core barrel and split-steel inners giving a core with a minimum diameter of 50 mm. Whenapproved by the Field Supervision Geologist, wireline core barrels with a split steel liner giving acore with a minimum diameter of 47.5 mm may be used.

The core barrels shall not exceed 1.5 m in length except with the approval of the FieldSupervision Geologist. With this equipment, drilling lifts (runs) shall be made as often asnecessary to obtain the maximum possible core recovery, provided that no lift shall be longerthan the core barrel. When less than eighty per cent (80%) of the core is recovered from a run,the following run shall be halved in length, unless otherwise directed by the Field Supervision

Geologist. This requirement will normally be waived where the rock is completely or highlyweathered.

The use of rod-dope or grease on drill rods will not be permitted, nor will drilling mud be used,in spite of its advantages when drilling through fractured caving ground. Soluble oil, as anadditive to the drilling water, is permitted.

5.2 Reaming Casing and Grouting

To maintain water return, to identify zones of water losses or to prevent caving-in, the FieldSupervision Geologist may direct that part of the drillhole in rock be reamed out and steel casingset in it. Alternatively a length of the hole may be grouted if approved by the Field SupervisionGeologist. Cement and water or sand, cement and water may be used to grout the hole. Quic k

Set or similar should be added to the grout mix to shorten the set time. Grout is to be pumpedto the bottom of the hole via the drill rods. The drill rods are to be slowly withdrawn as the groutis injected so that water is displaced by the grout. The length of hole so grouted should be keptto a minimum.

5.3 Angle Drilling

The Field Supervision Geologist may, at a minimum notice of 48 hours before thecommencement of drilling, notify the Contractor that the hole shall be drilled at a prescribedangle to the vertical (inclination) and in a given direction (bearing).

The angle to the vertical shall not exceed 45. The drill rig setting shall be within 2 of the

prescribed inclination and bearing, but the actual angle drilled must be measured to the nearestdegree.

5.4 Boxing and Storage of Core

When removing core from the triple tube barrel, the split inner tube shall first be carefullyremoved using steady hydraulic pressure as required. Removal of the inner tube by hammeringis not permitted.

The recovered core is to be carefully placed in core boxes. Attached drawing (Figures 1 & 2)shows the dimensions and details of core boxes and the arrangement of core within the boxes.Each compartment shall be 1.05 m in length, to store core from 1.0 m of drilling. Compartmentsshall be numbered in sequence running from left to right. The drillhole number shall be clearly

marked on the end of the box, using paint or waterproof ink marker pens.

The cost of core boxes and core loss blocks shall be included in the rates for drilling.

8/13/2019 SPEC - 21 August 2013_220813

19/76


The depth of each lift shall be marked on the side of the box and also on the core at the end ofthe lift.

The core shall be placed in the box, starting at the lift and working back to the previous lift. (Ifnecessary a correction should be made for core growing or for core which has dropped out ofthe barrel during lifting). The cores from each drillhole are to be placed in separate core boxes.

All core pieces shall be carefully fitted together on breaks in the core due to joints or fractures oron breaks due to drilling stresses. The core must not be spread out or compressed in the boxes.

Where core losses occur, a red coloured wooden spacer block of square cross section tightlyfitting the core box shall be used to indicate the loss. Where the exact location of the core loss isunknown, the core loss spacer block shall be placed at the top of the lift in which the lossoccurred.

The core shall be maintained in a tidy, clean and dry condition on each drill site, until drillingoperations and logging of the core are completed, and the Field Supervision Geologist hasauthorised the removal of the core to the permanent core storage building. Photographing of thecore shall be done preferably at the same drillhole location. If not possible then it should be

done at the drillers camp as soon as possible (refer to Section12.2 ). The Contractor will beresponsible for the safe keeping of all the cores until they are delivered to the designatedstorage area. If in the opinion of the Field Supervision Geologist cores are lost or damaged dueto the fault or negligence of the Contractor, the Contractor may be required to replace them athis own expenses.

5.5 Measurement

Measurement, for payment, of core drilling of holes in rock to recover core between 47.5 mmand 60 mm diameter using a triple tube barrel with split steel liner including supply of coreboxes, handling and storing cores, protection and delivery of the core will be made of the lengthof holes drilled at the direction of the Field Supervision Geologist.

Measurement, for payment, of reaming of casing into rock will be made of the length of the holeso reamed and cased at the direction of the Field Supervision Geologist.

Measurement, for payment, of grouting drillholes including the supply of sand, cement andadditives to complete the work, standby whilst waiting for grout to set and redrilling the hole willbe made of the number of times grouting has been undertaken at the direction of the FieldSupervision Geologist.

5.6 Payment

Payment for core drilling of vertical and inclined holes in rock in the stage lengths given will bemade at the applicable rate per linear metre tendered therefore in the priced Bill of Quantities

(item 2.3).Payment for reaming of casing into rock will be made at the applicable rate per metre tenderedtherefore in the priced Bill of Quantities (item 2.3).

Payment for grouting drill holes will be made at the applicable rate tendered therefore in thepriced Bill of Quantities (item 2.3).

8/13/2019 SPEC - 21 August 2013_220813

20/76


6 HAND HELD DRILLING

6.1 Equipment

Coring Equipment

The Contractor shall advance the drill holes using water fed rotary hand held drill (hand heldconcrete drilling machines are appropriate for this task). The drill bit should be `N size indiameter, capable of recovering samples with lengths at least 1.9 times their diameter andshould be tipped with diamonds or tungsten carbide.

Power Source

For electrical powered drills a generator and sufficient wires will be required.

Water Supply

Two water tanks will be required: one to store enough water to complete the drilling, and asecond tank to collect returning water.

Support

In order to prevent injuries and damage to the core, drill stands, rockbolts and anchors areallowed.

Retrieving Tools

Hammer, screw driver, wire and other tools which can be used to retrieve the coe sample fromthe core hole or from the bit.

6.2 Priority

The drilling of samples for engineering structures shall receive priority over the drilling ofsamples for material borrow areas.

The priority of all the samples to be drilled will be indicated and confirmed by the Engineersrepresentative on site.

6.3 Positioning of the Hand Held Drill

When possible, samples should be taken vertically. If the rock surface does not allow for avertical hole, then the samples should be drilled perpendicular to the ground surface.

The equipment is portable. However, the process of drilling one sample can take a long timeand the torque of the machine can become a burden for the operator. To prevent relativemovement that could result in distorted or broken core, the drill should be supported and bracedagainst the ground.

6.4 Procedure

Ensure that the coring bit is clean before starting.

Position the core bit perpendicular to the ground.

Connect the water supply to the machine and start a slow flow of water before startingthe machine.

Core the rock sample.

Remove the sample from the drill bit and log it and describe it as perAppendix A andAppendix B.

8/13/2019 SPEC - 21 August 2013_220813

21/76


The Engineers Representative will be responsible for labelling, registering and wrappingthe sample.

Clean the drill bit and be sure that all of the core has been removed before drilling thenext sample.

6.5 Measurement

Measurement for payment will be made of the number of samples collected. Measurement willnot be made for broken samples.

6.6 Payment

Payment for collecting hand held drilling samples will be made at the rate per sample tenderedtherefore in the priced Bill of Quantities (item 3.3.2).

8/13/2019 SPEC - 21 August 2013_220813

22/76


7 GROUNDWATER

7.1 Groundwater Observations

During all drilling operations, the Contractor shall have on site an approved electrical water-levelmeasuring device. Levels shall be read to an accuracy of 1 to 2 cm to 50 m depth.

All records of measurement shall contain the hole number, date and the time of day on whichthe measurement was made. The level of the bottom of the hole and the bottom of the casing, ifany, shall be measured and recorded at the same time as each water level reading. Readingsshall be taken at the beginning of each shift and if any changed condition is anticipated. Oncompletion of the drillhole groundwater observations will continue at weekly intervals until thedate of completion of the site works.

The cost of groundwater observation shall be included in the rate for drilling tendered thereforein the priced Bill of Quantities.

Some drillholes will be nominated as standpipes for groundwater observation. These holes shallbe kept open with perforated PVC pipe 25 mm in diameter taken to the bottom of the hole andfitted with a substantial cap at the ground surface. The top of the hole shall be protected with acover consisting of a threaded plug or cap on the end of the water pipe projecting no more than100 mm above the ground surface. For a satisfactory groundwater level observation, thedrillhole designated as an observation well should be flushed thoroughly with clean water at thecompletion of the drilling. After the pipe is installed, the surface annulus between the walls of thehole and pipe are to be sealed with concrete to prevent ingress of surface water and to securethe pipe.

Provision shall be made for measuring artesian water levels where directed by the Field

Supervision Geologist.

7.2 Measurements

Measurement, for payment, for installation of standpipes in drillholes for groundwaterobservations will be made of the length of perforated 25 mm PVC pipe supplied and installed atthe direction of the Field Supervision Geologist.

7.3 Payment

Payment for installing standpipes in drillholes for ground water observations will be made at theapplicable rate per metre tendered therefore in the priced Bill of Quantities (item 2.4.6). Thisrate shall not include the cost of drilling the hole.

8/13/2019 SPEC - 21 August 2013_220813

23/76


8 TEST PITS AND AUGER BORING

8.1 TEST PITS

8.1.1 General

Test pits may be excavated by hand or by machine at locations designated by the FieldSupervision Geologist. They shall be excavated and finished in a condition which permits thesafe entry into the pit by the Contractors or Employers staff. The Contractor shall provideladders or other facilities which will enable a close and safe inspection of the excavation by theField Supervision Geologist.

8.1.2 Size

The pits shall be excavated with the following minimum dimensions: width 1 m, length 1.5 m.The minimum depth shall be 3 m unless ground conditions preclude manual excavation or

excavation using a tracked excavator or similar. The pits shall be parallel sided.

8.1.3 Safety

The Contractor shall be responsible for all aspects relating to safety of the pits, including thedecision to use or not to use bracing to support the walls. Test pits deeper than 1.5 m deep shallbe supported with particular attention given during wet weather and in location where a highwater table is present or suspected. Safety helmet shall be worn when entering deep excavationand there shall be workmen remaining outside of the excavation.

8.1.4 Backfilling

Backfilling shall be carried out as soon as practicable after the Field Supervision Geologist giveshis approval for backfilling. Backfilling shall be mounded to at least 0.5 m above natural surface.

8.1.5 Logging

Copies of handwritten logs of test pits shall be provided to the Field Supervision Geologist oncompletion of each test pit. The logs shall be made available to the Field Supervision Geologistat any time upon request for checking.

The log shall show a visual description of each stratum, the depth of each stratum, the locationof all samples, profiles of pocket penetrometer and pocket vane shear strength with depth (infine grained clayey soils) and notes pertaining to moisture content variation and groundwaterinflow. Logging of the pits shall be carried out as the pit is advanced. The Contractor shallsupply one colour print for each test pit.

8.1.6 Disturbed Samples

Disturbed samples with a mass of approximately 1 kg shall be taken at intervals of 0.5 m depthand at changes in soil strata as the pit is advanced. The samples shall be sealed in thickpolythene bags or screw-top glass jars to preserve the moisture content.

Bulk disturbed samples with a mass of approximately 20 kg shall be taken from depths directedby the Field Supervision Geologist.

All samples shall be clearly marked and labelled with the job number, test pit number, samplenumber and sample depth. The samples shall be stored at the drillers campat the end of eachday, and when directed by the Field Supervision Geologist transported to the laboratory.

8/13/2019 SPEC - 21 August 2013_220813

24/76


8.1.7 Undisturbed Block Samples

Undisturbed block samples shall be taken by the Contractor from locations selected by the FieldSupervision Geologist. These samples will be nominally 300 x 300 x 300 mm, unless a smallersize is approved by the Field Supervision Geologist.

Block Samples shall be taken from fresh exposures as the pit is excavated in accordance withU.S.B.R. Earth Manual Test Designation E-2 Part A. The samples, however, shall beimmediately sealed, using a light covering of plastic film (e.g. Gladwrap), followed by a tightcovering of aluminium foil. The samples shall then be coated in wax to provide an airtight sealbefore placing in a wooden box. The gaps between the sample and inside of the box shall befilled with wax, expanding polystyrene foam or other material approved by the Field SupervisionGeologist in order to minimize handling disturbance to the sample. The wooden box shall beconstructed of plywood with a minimum thickness of 12 m, the outside of the box stiffened withtimber on the corners and the sides screwed together to provide an adequately strong androbust container for the sample. On the top of the boxed sample, a label shall be clearly markedto indicate; job number and name, pit number, sample depth, sample number and orientation.

8.1.8 MeasurementMeasurement, for payment, of excavating test pits including logging and the recovery ofdisturbed samples and delivery to the laboratory will be made of the depth of each test pit at thedirection of the Field Supervision Geologist.

Measurement, for payment, of undisturbed block samples obtained from test pits will be made ofthe number of undisturbed samples taken at the direction of the Field Supervision Geologist.

8.1.9 Payment

Payment for excavating test pits, including the recovery of disturbed samples will be made atthe rate per metre tendered therefore in the priced Bill of Quantities (item 3.1).

Payment for undisturbed block samples will be made at the rate per sample tendered thereforein the priced Bill of Quantities (item 3.3.2).

8.2 Power Auger Boring

8.2.1 General

Power auger holes shall be not less than 100 mm diameter. The auger shall be withdrawncompletely from the hole at intervals not exceeding 1 m penetration. A disturbed sample ofapproximately 0.5 kg shall be taken from the bottom 300 mm of the auger at each withdrawal.Material which is judged to be not representative of the material at the bottom of the hole shallbe excluded before sample. No sample shall be collected from the collar of a hole or from augerflights above the bottom 300 mm. Auger flights shall be fully cleaned after each withdrawal.

Bagging for moisture content measurement shall be as for disturbed samples as described inSection4.2 of this Specification. Copies of hand written logs of each power auger hole shall beprovided to the Field Supervision Geologist on completion of each power auger hole.

8.2.2 Measurement

Measurement, for payment for power auger holes will be made of the length of auger hole putdown at the direction of the Field Supervision Geologist.

8.2.3 Payment

Payment for power auger holes will be made at the applicable rate per linear metre tenderedtherefore in the priced Bill of Quantities (item ???).

8/13/2019 SPEC - 21 August 2013_220813

25/76


9 INSITU TESTING

9.1 Standard Penetration Test

9.1.1 General

During the drilling of cased or uncased vertical drill holes Standard Penetration Tests (SPT) willbe undertaken in overburden at depths directed by the Field Supervision Geologist.

9.1.2 Equipment

The equipment shall be in good working condition and shall comply with BS 1377 Test 19. Thehammer shall be an automatic trip hammer.

9.1.3 Test Method

The test method shall be in accordance with BS 1377 Test 19. A split-barrel sampler is to be

used except that a cone tool may be used in gravels. Blow counts of greater than 25 for 150 mmpenetration or greater than 50 for 300 mm penetration are recorded as effective refusal (R).

The whole of the material removed from the SPT split tube shall be immediately sealed topreserve its natural moisture content. If more than one type of material is represented, each soiltype shall be placed in a separate container, taking care to record the relative position of eachmaterial. When a satisfactory sample is not obtained from the split barrel of the sampler, orwhen a cone tool is used, a representative disturbed sample with a mass of not less than 1 kgshall be obtained by some other approved technique.

When testing above the water table, the casing is kept full of water.

9.1.4 Correction of Results

Field test values of N have to be corrected for several factors including the overburdenpressure. The greater the overburden pressure the higher the N value for the same densityindex.

For normally consolidated non cohesive soils the best correlation is:

Density Index (%) Conditions N1

0 - 15 Very Loose 0 - 3

15 - 35 Loose 3 - 8

35 - 65 Medium Dense 8 - 25

65 - 85 Dense 25 - 4285 - 100 Very Dense > 42

Where N1= CNN and N is blow count corrected as above

for fine sands CN =2

1'

for coarse sands CN =3

2 '

where is the effective overburden pressure in tons/square foot (1 tsf = 107 kPa).

8/13/2019 SPEC - 21 August 2013_220813

26/76


9.1.5 Measurement

Measurement for payment of Standard Penetration Tests shall be made of the number of testscompleted at the direction of the Field Supervision Geologist, including tests terminated due tohigh resistance.

9.1.6 PaymentPayment for standard penetration tests will be made at the rate per test tendered therefore inthe priced Bill of Quantities (item 2.4.2).

9.2 Single Packer Field Permeability Test

9.2.1 General

When directed by the Field Supervision Geologist, single packer permeability tests shall becarried out in sections of diamond drill hole in rock as the hole is drilled. By this method, thebottom section of the hole (3 to 10 m in length) shall be isolated and the rate of water loss fromthis section under different pressures is measured.

9.2.2 Equipment

Adequate water storage for completion of the test shall be provided. Water used shall be cleanand free of suspended matter and sediment.

A centrifugal pump capable of delivering at least 100 litres per minute against a pressure of 700kPa shall be provided. As constant water pressure is required during the test, a reciprocatingpump used during normal drilling operation is not acceptable.

The water meter shall be capable of accurately reading to 0.5 litres and capable of handlingflows up to 100 litres per minute. A second meter shall be available as a check; both metersshall have been recently calibrated. Evidence of the calibration of these water meters will berequired prior to their use in the field. To reduce the effects of turbulent flow, the meter shall beconnected on either side to straight pipe with a length at least 12 times the rated diameter of themeter.

Water pressure shall be measured using an electrical pressure transducer located within thetest section at the bottom of the hole. A digital display of the electrical output of the pressuretransducer, in terms of kilopascals (accuracy + or - 5 kPa) shall be provided at the groundsurface. Water pressure gauges shall be provided as a back-up and check for the pressuretransducer. The pressure gauges shall be precision gauges of durable construction and ofstandard test quality. Pressure gauges shall be selected such that they suit the pressure range.Suitable gauges are:

0 - 500 kPa graduated in 20 kPa increments

0 - 1 000 kPa graduated in 50 kPa increments (for inflating packer)

Because pressure gauges tend to be inaccurate towards the upper limit of their range, it isrequired that 2 or 3 pressure gauges with different ranges be used as indicated below:

Pressure Range Use Gauge With The Range (1 kg/cm = 98.07 kPa)

0 - 300 kPa

300 - 800 kPa

0 - 500 kPa

0 - 1000 kPa

The pressure gauge shall be coupled directly to the drill rods in the hole so that no bends occurin the water line between gauge and the test section. The water meter should be coupleddirectly in a straight section of pipe between pump and drill rods. The water line shall be free ofangular bends as far as possible.

The contractor shall get approval from the Field Supervision Geologist of any other method tomeasure the water pressure. The test section shall be sealed by an approved pneumaticpacker. For other than a packer coupled to `N rods with stream flow couplings or fitted with a

8/13/2019 SPEC - 21 August 2013_220813

27/76


downhole electrical pressure transducer the head loss within the rods and packers shall bemeasured for various rod lengths.

All measuring equipment should be frequently calibrated. Friction loss through the water systemis particularly important. Packers are individually manufactured and each has different frictionalcharacteristics to water flow. The friction loss through each packer and water line is established

by connecting the packer and a section of water line to the pressure gauge, water meter andpump. Hydraulic packers should be calibrated in the open position.Water is pumped throughthe packer and line with flow rates recorded for several readings of back pressure. The additionof a second section of water line provides an incremental increase in friction loss for each lengthof line. Calibration sheets should identify the packer, rod type, length and date.

9.2.3 Test Procedure

Before testing, the static groundwater level shall be measured at the beginning of the shift.Immediately after drilling the test section, the hole shall be flushed with water pumped throughthe drill rods until the water return is clear. The packer shall then be lowered into position andinflated. The exact position of the packer and the distance from the collar of the hole to thepressure gauge shall be measured.

Water shall be pumped into the hole at gauge pressures as tabulated below for each testsection of hole:

Vertical Depth Below Surface Pressures To Be Used (kPa)

3 m to 6 m6 m to 15 m15 m to 30 mbelow 30 m

25 50 75 50 2525 75 150 75 2575 175 350 175 75

150 350 700 350 150

For each test section three tests shall be conducted at each gauge pressure for equal periods of5 minutes, or until a steady leakage rate is obtained in two successive 5 minute periods.

During the testing, the details of time, gauge pressure, water meter readings, water loss,leakage rate, sealing properties of the test section and any other relevant information shall berecorded on the Pressure Testing Report. A sample form for the Water Pressure Test Report isincluded in0.

On completion the water pressure test, and removal of the test equipment from the hole, thetime of completion shall be entered on the log, the water level in the hole measured andrecorded, and the Pressure Test Report signed by the Drilling Supervisor.

If the test section cannot be sealed satisfactorily and the leakage occurs between the packerand the hole wall, the packer may be re-set at lower depths until an adequate seal is obtained.

The results of this test indicate the water loss in relation to the effective pressure (gaugepressure plus water column pressure less friction loss) which is the interpreted Lugeon value.Results shall be tabulated and plotted graphically to illustrate the pressure/water lossrelationship. The best fit straight line (not necessarily through the origin) indicates theincremental flow/pressure relationship. The parallel line to this best fit line, passing through theorigin, represents adjustments for water column pressure and is then extrapolated to 1000 kPato give the interpreted Lugeon value.

9.2.4 Measurement

Measurement, for payment, of performing and recording results of single packer drillholepermeability tests will be made of the number of tests carried out at the direction of the FieldSupervision Geologist.

8/13/2019 SPEC - 21 August 2013_220813

28/76


9.2.5 Payment

Payment for performing and recording single packer drill hole permeability tests in the stagelengths 0-50m and 50-100m will be made at the applicable rate per test tendered therefore inthe priced Bill of Quantities (item 2.4.1).

9.3 Constant Head Permeability Tests

9.3.1 General

When directed by the Field Supervision Geologist constant head permeability tests shall becarried out in holes with or without casing.

9.3.2 Equipment

The Contractor shall provide all equipment necessary for performing the tests accordance withUSBR Earth Manual Test Method E19 or E18 Section 4 as applicable. The equipment shallconsist of but not be limited to:

a means for maintaining the water level at a constant level. This constant level will beapproximately at natural surface.

a water reservoir of at least 200 litres capacity to feed the constant water level system

a means of measuring the volume of water consumed to the nearest 1 litre

9.3.3 Test Method

The tests shall be performed as constant head inflow tests in accordance with the USBR EarthManual Test Method E19 or Test E18 Section 4.

The tests shall be performed in clean holes free of loose soil particles using a method of holesupport which is appropriate for the ground conditions. For example an open unsupported holemay be appropriate in residual clay soils, or open-ended casing may be appropriate for

saturated alluvium. The method of hole support shall be subject to approval by the FieldSupervision Geologist.

Prior to testing the dimensions of the hole, depth of casing (if any) and natural level of thegroundwater shall be recorded. The constant water head, the level of which is to be recorded,shall be maintained until a constant flow rate has been clearly established or for a minimum of 1hour, whichever is the lesser. Records of time and volume of water shall be maintained toindicate the flow rate.

A sample of soil of at least 1 kg weight shall be obtained from the test zone. This sample shallbe classified in accordance with the Unified Soil Classification System.

9.3.4 Test Results

Test records shall include all hole dimensions, the natural groundwater level, applied head anda tabulation showing the volume of water entering the soil and the corresponding time. Thecoefficient of permeability of the test zone shall be calculated and a description of the soil in thetest zone given.

9.3.5 Measurement

Measurement, for payment, of providing, setting-up and dismantling constant head permeabilityapparatus will be made of the number of tests performed at the direction of the FieldSupervision Geologist.

Measurement for payment, of performing and recording results of constant head permeability

tests will be made of the time taken to perform tests carried out at the direction of the FieldSupervision Geologist.

8/13/2019 SPEC - 21 August 2013_220813

29/76


9.3.6 Payment

Payment for providing, setting-up and dismantling constant head permeability apparatus will bemade at the rate per test tendered therefore in the priced Bill of Quantities (item 2.4.4).

Payment for performing and recording constant head permeability tests in drillholes, includingrig standby will be made at the rate tendered therefore in the priced Bill of Quantities (item2.4.4).

9.4 Variable Head Permeability Tests

9.4.1 General

When directed by the Field Supervision Geologist variable head permeability tests shall becarried out in auger holes or drillholes, with or without casing. The tests will either be of thefalling head type or raising head type, where the water level is initially lowered by bailing orpumping.

9.4.2 Equipment

The Contractor shall provide all equipment necessary for performing the tests including:

a means of lowering the groundwater level by pumping or bailing. a means of measuring the water level in the hole using an electrical type water level

indicator

9.4.3 Test Method

The tests shall be performed using a method of hole support appropriate to the groundconditions. The method of support shall be subjected to the approval of the Field SupervisionGeologist.

Prior to testing the dimensions of the hole, depth of casing (if any) and natural level of the

groundwater (to an accuracy of 2 cm) shall be recorded.In the case of falling head permeability tests, water shall be added to the hole to a specifiedlevel. Tabulation shall be provided of the time and corresponding water level in the hole as itfalls to the natural groundwater level. The water level in the hole shall be recorded until itreaches the natural groundwater level or for a minimum of 6 hours whichever is the lesser.

In the case of rising head permeability tests water shall be removed from the hole by pumpingor bailing to a specified level. Tabulation shall be provided of the time and corresponding waterlevel in the hole as it rises to the natural groundwater level. The water level in the hole shall berecorded until it reaches the natural groundwater level or for a minimum of 6 hour whichever isthe lesser.

A sample of soil of at least 1 kg weight shall be obtained from the test zone. This sample shallbe classified in accordance with the Unified Soil Classification System.

9.4.4 Test Results

Tests records shall include all hole dimensions, the natural groundwater level, initial head ofwater and a tabulation showing the water level in the hole and the corresponding time. Adescription of the soil in the test zone shall be provided and the coefficient of permeabilitycalculated.

9.4.5 Measurement

Measurement, for payment, of providing bailing or pumping apparatus including the bailing outor pumping out of auger holes or drillholes will be made of the number of tests performed at the

direction of the Field Supervision Geologist.

8/13/2019 SPEC - 21 August 2013_220813

30/76


Measurement, for payment, of performing and recording results, of variable head permeabilitytests will be made of the time taken to perform tests carried at the direction of the FieldSupervision Geologist.

9.4.6 Payment

Payment for providing bailing or pumping apparatus, including bailing out or pumping out theauger holes or drillholes will be made at the rate per test tendered therefore in the priced Bill ofQuantities (item 2.4.3).

Payment for performing and recording variable head permeability tests in drillholes, including rigstandby will be made at the rate tendered therefore in the priced Bill of Quantities (item 2.4.3).

Payment for performing and recording variable head permeability tests in auger holes, will bemade at the rate tendered therefore in the priced Bill of Quantities (item 2.4.3).

9.5 Pressuremeter Tests

9.5.1 General

When directed by the Field Supervision Geologist pressuremeter tests shall be carried out inuncased drillholes or auger holes in residual soil or weathered rock.

9.5.2 Equipment

The pressuremeter and associated equipment shall incorporate the following features:

a pressure indicating system which enables pressure measurement to an accuracy ofbetter than 5% to a maximum pressure of 10 MPa;

a system which enables measurement of hole diameter to an accuracy of better than0.01 mm. The system shall measure diameter directly; systems based on themeasurement of volume of a test cell are not acceptable. Acceptable pressuremeters

include the OYO 100, LNEC and similar.The measur

spec - 21 august 2013_220813

Documents