NN3 Site Investigations Spec

8/6/2019 NN3 Site Investigations Spec

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NAM NGUM 3 HYDROELECTRIC PROJECT

SITE INVESTIGATION

DRAFT' TECHNICAL SPECIFICATION

S1.00 NATURE AND EXTENT OF CONTRACT

1. This Contract covers field and laboratory investigations to provide information onground conditions at the site of the proposed Nam Ngum 3 Hydroelectric Project inLaos PDR. The area is rugged and remote and the specification clauses have beenwritten to allow for these constraints which should be considered by the Contractor inhis submission.

The project program provides for completion of the field investigations within six

calendar months of commencement and the Contractor's submission should take thisinto account. It is expected that up to four drilling rigs will be required to meet this

program and that mobilisation and rig moves between drill sites will requirehelicopter assistance.

2. The work required under this contract comprises:

a. Core drilling by wire-line methods using triple tube barrels: includingrecovery and handling of core, keeping records of drilling operations, loggingof drill core and colour core photography.

b. Water Pressure testing of drill-holes downstage by pumping in water underpressure and keeping records of the tests.

c. Wash boring and keeping records of the drilling operations.

d. Percussion drilling: including keeping of drilling records and samplecollection.

e. Transportation from site of core boxes and samples.

f. Laboratory testing of rock samples and reporting of results.

g. Production and laboratory testing of concrete aggregate for concrete trialmixes.

h. Conduct of concrete mix design trials.

i. Provision of a specialist sub-contractor, to undertake hydraulic fracture andhydraulic jacking testing.

3. a. The site of the Works is located on the Nam Ngum River 180 kmnortheast of Vientiane. The area has a relief of about 600 m with many steep

slopes; it is sparsely populated with a dense cover of vegetation; there are few

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tracks.

b. The work sites include:

- the storage damsite and related structures including spillway and

diversion tunnels

- power tunnel and underground power station

- quarry for rockfill and concrete aggregate.

These works are spread over an area of some 30 kilometres.

3. a. The drilling program cannot be planned exactly at this stage. Thenumber, location and inclination of holes will be determined progressively inthe light of information obtained from geological mapping and from holes

drilled previously. The unit quantities in the Schedule of Quantities and Rateshave been based on an estimate using currently available information. It isexpected that the total drilling length will be between 2800 m and 3600 m andthat about 27 holes will be involved.

b. The estimated breakdown of drilling required in each of the areas is tabulatedbelow. A detailed breakdown is given in Appendix A.

Location Number of Holes Total Length

Damsite 11 775 m

Spillway/ Diversion Tunnel 3 300 m

Power Tunnel/ Penstock/ Power Station 10 1 425 m

Quarry 3 900 m

c. These figures are provided only for the information of tenderers and are not to be considered binding; changes in the individual and cumulative lengthsdrilled will not be grounds for variation in the rates shown in the Schedule ofQuantities and Rates (hereinafter called the Schedule).

5. Core drill-holes may be vertical or inclined as required in the schedule. Verticalholes are defined for the purpose of this Contract as holes drilled within 10 degrees ofvertical. Angled holes are defined for the purpose of this Contract as holes at a greaterangle than 10 degrees from the vertical. Separate rates for vertical and angled drillingshould be included in the Schedule. It is expected that no holes at angles less than 45degrees to the horizontal will be required.

6. Drill-holes are expected to range in length from about 50 m to 310 m.

7. Laboratory testing of the rock samples should be conducted concurrently with thefield investigation program. The samples to be prepared and tested and the range of



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testing will be specified by the Client's Representative based on the unit rates fortesting submitted in the Schedule. The quantity of tests shown in the Schedule isindicative only. Changes in the number of individual tests will not be grounds forvariation in the rates shown in the Schedule. The result of all laboratory testingshould be provided by the Contractor within one calendar month of completion of the

field investigations.

8. The Contractor shall be prepared to commence work on the Site within 28 days of theissue of the Letter of Acceptance.

9. The work on the Site will be supervised by the Client's Representative who will bestationed at the Site. Accommodation is to be provided for SMEC and MDX

personnel at the power station site.

S2.00 ACCESS

1. There is, at present, no vehicular access to the site of works. Current access is by foottrack or by helicopter. It is expected that helicopter support will be required for siteestablishment and rig transfer between drill sites. All approved helicopter hire will be

paid for by MDX.

2. Establishment on site will require the clearing of helipads and the preparation ofdrilling platforms. Access tracks to the different areas of investigation, the drillingsites and across the Nam Ngum River will be required. The construction andmaintenance of these access tracks and crossings shall be the responsibility of theContractor who shall include all costs involved in the rates submitted in the Schedule.

S3.00 ESTABLISHMENT, EQUIPMENT, MATERIALS AND SUPPLIES

1. The Contractor shall provide the following:

a. Hydraulic feed drilling rigs equipped with wire-line equipment capable ofrecovering NQ size core in angle holes between 45' and 90' from thehorizontal, at least two of the rigs should have the capability of drilling to adepth of 350 m, using triple tube core barrels.

b. Adequate supplies of casing, triple tube core barrels, drill rods, cement,drilling mud, fuel, lubricants, and all accessory drilling equipment to carry out

the proposed program without delay.

c. All pumps, water lines, tanks, packers, gauges, water meters, water levelmeasuring equipment and all other necessary equipment to enable effectivedownstage water pressure testing of drill holes.

d. Tools for the excavation and collection of materials for the production ofconcrete aggregate for testing and concrete trials.

e. Core boxes and sample bags for the storage of samples

f. A portable point load tester.



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g. All facilities and supplies required to satisfactorily accommodate his personnel. As mentioned in Clause S1.9 accommodation for the Client'sRepresentative personnel is also required at the power station site.

2. Notwithstanding anything in Clause S3.01, the Contractor will be responsible for thesupply of all equipment, materials and supplies necessary to complete the job to thesatisfaction of the Client's Representative.

3. a. The Tenderer shall submit with his Tender a lump sum rate for themobilisation and demobilisation of his plant and personnel at the Site of theWorks. This lump sum rate shall include all costs involved in transporting his

plant and equipment by land to the project area, the establishment of the sitebase camp, the construction of access tracks, the clearing of the drill platformsand all costs involved in rig set up at these sites including provision of drillingwater and all equipment to enable drilling to commence. The lump sum rate

shall also include the cost of removing all the Contractor's equipment fromsite on completion of the Contract.

b. Payment for mobilisation and demobilisation of plant and personnel at the Siteof the Works will be made at the lump sum price tendered therefor in theSchedule under Item 1.1.

S4.00 CONTRACTOR TO ACCEPT RISKS

1. The Contractor shall accept all risks of damage to his plant or property from fire,flood, theft, or any other cause.

2. The Contractor shall be held totally responsible for property damage caused throughcareless or negligent operation of his plant or equipment, or through wilful, careless,or negligent acts or omissions committed by himself, his employees or hissub-contractors.

3. The Contractor shall drill holes of uniform diameter and straight sides to enable waterpressure testing over any section required by the Client's Representative. Should it benecessary to abandon a drill-hole before completion, due to jammed equipment orcrooked holes caused by inferior or faulty equipment or negligence of the Contractoror his representatives, the Contractor may be directed to drill a second hole alongside

the first at no cost to the Principal.

4. A major objective of this Contract is to recover rock core. The Contractor shouldmake every effort, by equipment and drilling methodology to ensure that themaximum practicable recovery of core is achieved. If the Client's Representativeconsiders that core recovery has been affected by faulty equipment or poor drillingmethods the Contractor may be directed to drill another hole nearby at no cost to thePrincipal.

5. A major objective of this Contract is to measure rock mass permeability. TheContractor should make every effort, by equipment and methodology to ensure that

water pressure testing is carried out in accordance with this specification. If the



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Client's Representative considers that water pressure test results have been affected byfaulty equipment or poor testing methods the Contractor may be directed either torepeat the test or to drill another hole nearby and test it at no cost for drilling ortesting to the Principal.

S5.00 CONTRACTOR'S RESPONSIBILITIES

1. The Contractor shall appoint a Site Supervisor who shall:

- be present on site on a full time basis- be responsible for all the Contractors activities on site- liaise with the Client's Representative on all matters relevant to the Contract

The Contractor in his submission shall nominate the Site Supervisor and providedetails of his experience.

2. The Contractor shall, from time to time as the several portions of the work arecompleted, tidy up each work site and remove all plant, equipment, unused materials,rubbish, to the satisfaction of the Client's Representative.

3. The Superintendent may at any time direct that the Contractor remove any person,agent or assignee of the Contractor, or any sub-contractor, from Site. The Contractorshall, after receiving written notice of such direction, remove the person(s) from Siteand shall not thereafter employ them again on the Works in any capacity and shallreplace them by other personnel approved by the Principal. The Contractor shall not

be entitled to any compensation or any extension of time if such a direction is issued.

4. Separate Payment will not be made for this Work. Such costs shall be deemed to beincluded in the applicable rates and lump sums for the Works.

S6.00 DRILLING

1. The location and designation of drill-holes and order of drilling will be determined bythe Client's Representative at the earliest possible time. The drill sites will be located

by the Contractor's surveyor before drilling platform preparation commences.

2. The Contractor shall set up his rig so that the drill-hole is as close to the site peg aspossible.

3. During drilling or water pressure testing, water pumped into the hole shall be free ofall suspended solids. It shall be the Contractor's responsibility to obtain clean waterand to supply all pipes, fittings, tanks, pumps, water trucks, etc., to conduct water tothe drill-hole locations.

4. The use of 'rod dope', grease, or other external lubricants on the drilling rods, oradditives other than soluble oil in the drilling water, will not be permitted. In extremedrilling conditions, the use of revertible drilling mud in the upper parts of a hole may

be permitted; before commencing coring of any section to be water pressure testedthe hole shall be cased off and all mud in the hole and circulation lines shall be

flushed out with clear water. External lubricants may be used on casing.



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5. Specifications will be issued by the Client's Representative for each drill hole. Thesize of the hole shall, unless otherwise directed, be 'N' size. Changes of core sizeshall be made only with the approval of the Client's Representative. Triple tube core

barrels shall be used.

6. Before commencing drilling in any hole, a working peg shall be driven into theground within 0.5 m of the drill stem in a position in which it will not be disturbed.The height of this peg above or below ground surface at the hole shall be measuredand recorded in the driller's log. All depths in the hole shall be quoted with respect toground surface at the commencement of drilling and shall be taken as the distancedrilled from that surface whether the hole is vertical or not.

7. All measurements in the hole shall be to the nearest 0.01 m.

8. Holes will be checked for inclination and bearing by the Client's Representative prior

to the commencement of drilling. A tolerance of 1' will be permitted.

9. Core recovery is of prime importance. Drilling lifts (runs) shall be performed toobtain maximum possible core recovery and in general shall not be more than 1m.

10. Unless otherwise directed by the Client's Representative coring will begin fromground level or as soon as coreable rock is struck, as directed by the Client'sRepresentative, and continue until completion of the hole. In a few holes wheredetailed information on near surface layers is not required, wash boring to rock may

be permitted by the Client's Representative.

11. Drilling above coreable rock shall be by wash boring. Unless otherwise directed, theContractor shall recover representative samples of overburden (soil strength material).These samples should be recovered at not greater intervals than 1 m. Soil samplesshould be sealed in a durable plastic bag and clearly marked with hole number andsample depth.

12. Reaming and casing, the use of drilling mud, or grouting of the hole to control cavingor high water loss, shall not be performed in any section of any hole without theapproval of the Client's Representative.

13. At the commencement of each shift the driller shall measure the standing water level

in the drill hole and record this measurement in his record.

14. On completion of the drill hole the contractor may be required to install a standpipe, piezometer, or other equipment, as directed by the Client's Representative. Nodrillhole is to be backfilled.

15. a. The Tenderer shall submit with his Tender separate unit rates per metre for:

- core drilling NQ vertical holes (Item 2.2)- core drilling NQ aagled holes (Item 23)

- wash-bore(non-core) drilling (Item 2.4)

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- percussion drilling (Item 2 )

b. Measurement for payment for core drilling of either vertical or inclined holeswill be made of the distance drilled, provided the core is handled and stored asin Clause S7.00 of this Specification.

c. Payment will be made for the actual distance drilled at the applicable unit rateper metre tendered therefor in the Schedule for core drilling under Items 2.2,2.3, 2.4 and 2.5.

S7.00 HANDLING AND STORAGE OF CORE

1. The Contractor will be responsible for:

- providing approved core boxes,- boxing the core in a proper manner,

- delivering the core to the core storage area designated by the Client'sRepresentative.

2. Boxes shall be constructed of galvanized steel or wood and shall be capable of storing5m of drill core. Each compartment shall be 1.05 m in length, to store core from 1.0m of drilling. The drill-hole number and depth interval of the core shall be clearlymarked on the outside end and on the lid of the box, using paint or waterproof inkmarker pens.

3. On completion of each drilling run, the core barrel shall be removed from the holeand the core carefully removed from the barrel by extracting the split inner tube,

splitting the tube to reveal the core and carefully placing the core in the core box.

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

5. Core shall be laid in the box reading across each row in succession from left to right.The shallower core shall be placed at the top left with the deeper core at the bottomright.

6. Core should be placed in the box in even metres. For example the left hand side of abox containing Depth 10 m to 15 m should have the core positioned in channels

marked as 10 m, 11 m, 12 m, 13 m, and 14 m.

7. All pieces of core shall be carefully fitted together at breaks along the core. The coremust not be spread out or compressed in the boxes. When core is broken to fit intothe box, it must be done with minimal force, so that the core is not damaged, and asnear as possible normal (right angle) to the core axis. Such a break shall be marked

by a "cross" using ink marker across the break to show that it was broken by hand.Any other breaks of the core that are incurred during handling shall be marked in thesame way.

8. Where core losses occur, a spacer block, tightly fitting the core box, shall be used to

indicate the true length of the loss. Where he exact location of the core loss is



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unknown, the core loss spacer block shall be laced at the top of the lift in which theloss occurred. The words "no core" and the depths of the loss, if known, shall beclearly written on the spacer block.

9. Only core from one drill-hole shall be placed in each box.

10. Colour photographs of each box are to be taken for all cored drill holes. The core isto be dampened prior to being photographed. Each photograph shall include projectname, drill hole number, depth range of core, core box number, core size and a

prominent scale graduated in 100 mm intervals. No core is to be removed from thecore box prior to being photographed.

11. The core shall be maintained in a tidy, clean and dry condition on each drilling siteuntil logging and photographing of the core is completed, and the Client'sRepresentative has authorized the removal of the core to the permanent core storagearea. If the lids of the core boxes are loose-fitting, then each box or group of several

boxes must be securely strapped during transport from the drilling site to the core

storage area. Travel to the core storage area shall be such that no damage and furtherbreakage of core occurs. Separate payment will not be made for core logging or corephotography. Payment shall be deemed to be included in the rate for core drilling.

12. All cores and boxes shall remain the property of the Principal.

13. The provision of core boxes actually used will be paid under Item 3.1 of the Scheduleof Rates. Separate payment will not be made for the handling of core andtransportation to the permanent core storage area. Such costs shall be deemed to beincluded in the applicable drilling rates.

S8.00 WATER PRESSURE TESTING

1. Water pressure tests shall be carried out in all cored holes apart from thosespecifically targeted at construction materials. Testing intervals will be specified bythe Client's Representative. Testing will be undertaken concurrently with the drillingof the hole, downstage, using a single packer.

2. Tests will not be expected in sections of hole where it is obvious that a good packerseal cannot be obtained.

3. Tests will generally be over sections of 10 m length, but in some cases a change in the

length of section may be required. For the deeper holes proposed (depth of about 300m) it is anticipated that it may be practicable to increase the water pressure testssection length in areas of low potential loss to about 20 m.

4. An accuracy of at least 0.1 m shall be required in the placing of packers.

5. a. The Contractor shall supply all equipment necessary for water pressuretesting including packers, pressure gauges, flow metres, couplings, pumpingequipment and delivery line capable of delivering 100 mm of non pulsatingflow at the drill-hole, at pressures up to 1600 kPa. This equipment shallenable the packers to be seated at any nominated depth in the hole.



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b. Packers designed for wire-line use are mandatory. Details of the make and modelproposed to be used shall be included in the Co~tractors submission.

c. The pressure gauges shall be precision instruments of durable construction, graduatedto read increments of 10 kPa, and of standard test quality. Gauges shall have recent

calibration certificates. Because pressure gauges tend to be inaccurate towards theupper limit of their range, the Contractor shall use 2 or 3 pressure gauges withdifferent ranges, as indicated below:

FOR APPLIED PRESSURE RANGE USE GAUGE WITH THE RANGE

0 - 400 kPa0 - 500 kPa

250 - 750 kPa0 - 1000 kPa

c. The water flow metres shall be capable of accurately recording flows to thenearest 0.5 litres and shall have been recently calibrated. To reduce theeffects of turbulent flow, the metre shall be connected on either side bystraight pipe with a length at least 12 times the rated diameter of the metre.

6. The pressure gauge shall be coupled directly to the drill rods in the hole so that nobends occur in the water line between gauge and test section. he water metre shall becoupled directly in a straight section of pipe between pump and drill rods. The waterline shall be as free of angular bends as possible.

7. Before water pressure tests commence at the site of works, the Contractor shall be

required to make his equipment available for testing for friction losses.

8. Before the packer is run into the hole, the section of hole to be tested shall be flushedclean to remove any drill cuttings which may have accumulated. The packerassemblies shall be run into the hole and be seated in positions required by theClient's Representative. Clean water shall be pumped into the section. The test shall

be run for at least 5 minutes per stage after a steady flow has been reached. Tests willusuaIIy be carried out in five stages.

9. Water shall be pumped into the hole at gauge pressures as tabulated below for eachtest section of hole, or as directed by the Client's Representative:

DEPTH INTERVALS (VERTICAL DEPTHBELOW SURFACE)

STAGE PRESSURE TO BE USED

from tokPa

5 m 20 m 50 100 150 100 50

20 m 50 m 100 200 300 200 100

below 50 m300 500 700 500 300



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10. Water pressure testing shall be carried out under the direction of the Client'sRepresentative but the Contractor will be responsible for the correct recording of thetest data.

11. a. The Tenderer shall submit with his Tender a unit rate per test for water pressure testing.

b. The unit rate for water pressure testing shall include all activities from thecessation of drilling before testing to the commencement of drilling aftertesting.

c. Payment for water pressure testing will be made at the unit rate per testtendered therefor in the Schedule under Item 4.1. Payment will not be madefor time spent on repairs, recovering jammed or lost tools, unsatisfactory testsdue to inferior or faulty equipment, or for time lost due to negligence or

inefficiency of the Contractor.

S9.00 FIELD ROCK STRENGTH TESTING

1. The Contractor will supply on site a portable Point Load Tester to enable fieldmeasurement of rock substance strength. The Contractor in his submission shallinclude details of the make and model of instrument which is proposed for approval

by the Principal.

2. The point load tester will be used during the process of logging of rock core. TheContractor will be required to carry out the Point Load Tests at a frequency directed

by the Client's Representative. Separate payment will not be made for Point LoadTesting. Such costs will be deemed to be included in the rates for drilling.

3. Payment for the supply of a calibrated Point Load Tester in good working conditionand any necessary maintenance during the project will be made a unit rate per actualday on site tendered under Item 7.1 in the Schedule of Rates.

S10.00 HOLE COMPLETION

1. On completion of drilling and water pressure testing, the bole shall be flushed outclean.

2. The hole location shall be marked by the insertion of a PVC pipe of 100 mm diameterand not less than 5 m long in the upper section of the hole. This pipe shall be firmlyset in concrete with 800 mm protruding above the ground surface and fitted with ascrewed cap.

3. Unless otherwise directed by the Client's Representative, installation of PVC pipeshall be carried out immediately on completion of the hole.

4. Should standpipe installation be required in any drill hole, 30 mm inside diameterPVC pipe shall be installed as directed by the Client's Representative. The hole is to

be sealed as per Clause S10.1.



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5. a. The Tenderer shall submit with his Tender a unit rate per metre for supplying and installing 100 mm and 30 mm inside diameter PVC pipeincluding pipe and end caps, as required under Clause S10.2.

b. Measurement for payment of installation of PVC pipe will be made of theactual length installed at the direction of the Client's Representative.

c. Payment for installation of PVC pipe will be made for the length certified bythe Client's Representative at the unit rate per metre tendered therefor underItems 6.1 and 6.2 in the Schedule.

S11.00 SETTING UP ON DRILLING PLATFORMS

1. After the initial mobilisation at six drill sites the Contractor will be paid for setting uphis rig or rigs at each drilling platform for additional drill holes as directed by the

Client's Representative for the purpose of drilling either vertical or inclineddrill-holes.

2. Setting up shall include any necessary site preparation, moving onto the hole, riggingup and down, placing water lines, and all other items not separately accounted for inSchedule.

3. a. The Tenderer shall submit with his Tender a unit rate per set up. Thisshall include all activities and costs involved from the completion of thedrilling at one site to the commencement of drilling at the next site.

b. Payment for setting up will be made at the appropriate rate per set up tenderedtherefor under Item 5.1 in the Schedule.

S12.00 STAND-BY TIME

1. The Contractor will be paid for stand-by time only in those cases where drillingoperations are suspended at the direction of the Client's Representative. The stand-byrate will not be paid for delays caused by weather, or breakdown of the Contractor's

plant or equipment, for time spent on water pressure testing, or for time spent onother works for which payment is made under other items.

2. The hourly rate for stand-by shall be deemed to apply during normal working hoursup to a maximum of 8 hours per day, six days per week.

3. The Contractor shall remain at the site of works to be eligible for stand-by payment.

4. The Client's Representative may perform other down-hole tests not included in thisContract. The Principal will supply the equipment for such tests but the Contractor's

personnel shall assist with the tests when directed by the Client's Representative. The period that the Client's Representative is performing such tests will be paid asstand-by time.

5. a. The Tenderer shall submit with his Tender a unit rate per hour for



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stand-by time.

b. Measurement for payment of stand-by time will be made of the actual timethat drilling operations are suspended at the direction of the Client'sRepresentative.

c. Time increments for stand-by time shall be recorded to the nearest fiveminutes, and ratified by the Client's Representative.

d. Payment for stand-by time will be made at the unit rate per hour tenderedtherefor under Item 10.1 in the Schedule.

S13.00 DRILLING RECORDS

The driller's log, the original copy of which shall be handed to the Client's Representative atthe completion of each shift, shall be provided by the Contractor, and shall show:

l. In the case of drilling:

a. Date, and start and finish times for each shift.

b. The name of the driller in charge of the drill.

c. The drill-hole number designated by the Client's Representative; theinclination and bearing of inclined holes.

d. Details of each drilling run: depth at end, distance drilled, core recovered,

description of core (or description of sludge where no core is obtained), positions of and reasons for core losses, drilling water loss or gain as apercentage, and notes on any abnormal observations on drilling conditions.

e. Details of water pressure testing; sampling and testing, running casing;cementing; moving of rig; and any similar work carried out during the shift.

f. The depth to water in the hole at the beginning of each shift accurate to 0.1 mas measured with an electric probe or other instrument approved by theClient's Representative.

g. Depth of ground surface at the drill-hole above or below working peg.

h. Details of stand-by time, if applicable, including times of start and finish andreasons for stand-by.

2. In the case of water pressure testing:

a. Date, and start and finish times for each test.

b. The name of the driller in charge of the testing.

c. The drill-hole number designated by the Client's Representative; the



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inclination and bearing of inclined holes.

d. The depth the drill-hole at the beginning of the test.

e. The depth to water at the beginning of the test.

f. Details of all equipment used in the test, including; packer type and size,length of rods and size, range of pressure gauges, height of the pressure gaugeabove the top of the holes, capacity and type of pump, type of water metre.

g. The depth at which the packer is set.

h. The length of test section.

i. Tabulated test readings for each stage giving applied pressure and successivetime and water metre readings.

3. Copies of the drillers shift report forms and water pressure test result sheet shall beincluded with the Contractors submission for approval by the Principal.

4. No separate payment shall be made for the provision and completion of the drillersshift report and water pressure test result sheet. All cost shall be included in thedrilling and testing rates submitted in the Schedule.

S14.00 LABORATORY TESTING

1. The engineering properties of the rock samples and concrete aggregate shall bedetermined by laboratory testing as specified by the Client's Representative.

2. The Contractor shall nominate for approval a laboratory/or laboratories and providedetails of equipment and experience. Only approved laboratories shall be used for thetesting.

3. The Contractor shall include in his submission unit rates per test for the tests listedunder Items 11.1 to 11.12 in the Schedule. The submission shall also include detailsof the relevant standard (ASTM or equivalent) which applies to the test method.

4. It is proposed that samples will be forwarded from site progressively during the fieldinvestigation. The laboratory testing program should take this into account. Final

reporting of laboratory tests is required within one calendar month of completion ofthe field work under this Contract.

5. As mentioned in Clause 1.08 the test quantities listed in the Schedule are indicative.Payment under Items 11.1 to 11.12 will be made for each test successfully completedand reported.

6. All material proposed for use as concrete aggregate are to be tested for compliancewith the appropriate standards (ASTM or equivalent).

S15.00 CONCRETE TRIAL MX PROGRAM AND LABORATORY TESTING



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1. The contractor shall undertake trials to design satisfactory concrete rnixes using thevarious aggregate sources available at the site. It is estimated that 20 to 30 trial mixeswill be required.

2. Aggregate is to be produced by the Contractor by crushing rock from the proposed

quarries sites or other suitable aggregate or rock source areas which will be usedduring construction. The cement source most likely to be used during constructionshall be used in the mix trials.

3. Concrete aggregate is to be tested by an approved laboratory as per Clause S14.2.The following testing shall be undertaken. This testing program is indicative, andadditional tests may be required based on proposed new aggregate source areas or onthe results of testing.

a) Alkali-Aggregate Reaction TestingTwo or more samples from each aggregate source, for each test type, will be

required to determine the reactivity of the aggregate. Both alkali-silica andalkali-dolomite reactivity testing is to be carried out. Specimens of each ofthe rock types are to be classified by optical petrography.

b) Coarse Aggregate TestingOne specimen from each of the proposed aggregate sources is to undergo thefollowing testing program

- rock type classification and particle shape assessment- crushing trials - coarse and fine- gradation and fineness modulus- aggregate crushing value

- SG, bulk density and absorption- sulphate soundness value- Los Angeles abrasion value- 10% fines

c) Fine Aggregate TestingSand samples from the proposed source to be used in construction shallundergo the following test program.

- gradation and fineness modulus- SG, bulk density and absorption- sulphate soundness

d) Trial Mix ProgramThe trial mix program will comprise:

- grading of aggregate- documentation of cement, flyash and water sources and quality- cement, water, admixture quantities- mix parameter ratios- properties of plastic concrete

* slump* air content* wet density

* temperature



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* bleeding %* setting times* workability* cohesiveness* harshness

- 7 and 28 day strengths

The testing will continue until satisfactory mixes have been devised for thevarious aggregate sources and concrete requirements.

4. Payment for conduct of the concrete trial program and production of aggregate shallbe made as a lump sum payment. The Contractor shall submit rates for this work,under Items 11.1 to 11.12 in the schedule, for approval by the Principal.

S16.00 HYDRAULIC FRACTURE AND HYDRAULIC JACKING TESTING

1. Hydraulic fracture and hydraulic jacking testing is to be undertaken in cored 300 mdeep drill holes located

a) above the power station and intersecting the cavern invertb) down the axis of the vertical pressure shaft.

2. Hydraulic fracturing testing is a specialist procedure for the determination of insitufield stresses in rock. A test section approximately 1 m long is isolated between twohigh pressure packers. Water is injected into the test section at a constant rate whilemeasuring pressure and time. Injection continues until a fracture is initiated in therock surrounding the test section. Three pressurisation cycles are used to determine

the various parameters required for the analysis of the magnitudes of stress.

3. Hydraulic jacking is used for determining the magnitude of the stress required to openan existing joint in the rock. A joint is isolated between two packers and the joint issubjected to incrementally increasing and decreasing pressure cycles, while recordingflow rates, until a non-linear increase in flow rate occurs. The magnitude of there-opening stress is determined from the graph of pressure vs injection rate.

4. Details of the testing required are set out in a separate document 'Nam Ngum 3Hydroelectric Project, Specification for Hydraulic Fracture and Hydraulic JackingTests'

5. The contractor shall, if required by the specialist Contractor and approved by theClient's Representative, provide a drilling rig and drilling crew to assist with the

placement of the testing equipment at any depth in the drill holes. Payment for theuse of drilling equipment and crew for the purpose of stress testing shall be made atthe 'standby rate'. Refer to Clause S12.00.

6. Should it be necessary to abandon a drill-hole, before completion of the stress testing program, due to faulty, inferior or jammed equipment, or negligence of theContractor or his representatives, the Contractor may be directed to drill a secondhole alongside the first in order to undertake further testing, at no cost to the

Principal.



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NAM NGUM 3 HYDROELECTRIC PROJECT

SITE INVESTIGATION

SCHEDULE OF QUANTITIES AND RATES

Item No. Description Quantity Unit Rate Amount

1.1 Mobilisation and demobilisation (seeClause S3.00)

Lump Sum

2.2 Vertical drilling NQ per metre (seeClause S6.00)

1850

2.3 Angled drilling NQ per metre (seeClause S6.00)

as required

2.4 Wash bore (non-core) drilling per metre(see Clause S6.00) 350

2.5 Percussion drilling per metre (seeClause S6.00)

1200

3.1 Core boxes per box (see Clause S7.00) 540

4.1 Water pressure testing per test (seeClause S8.00)

300

5.1 Set up on new drill platform per set up(see Clause S11.00)

23

6.1 100 mm PVC pipe per metre (seeClause S10.00)

130

6.2 30 mm PVC pipe per metre (see ClauseS10.00)

200

7.1 Supply of Point Load Tester per day(see Clause S9.00)

180

9.1 Accommodation and messing for Client=s Representative per man day(see Clause S1.10)

200

10.1 Stand-by per hour (see Clause S12.00) 100

11.0 Laboratory testing per test (see ClauseS15.00)

- - -

11.1 Sieve analysis (rock) 40

11.2 Specific gravity 20

11.3 Sulphate Soundness (rock) 10

11.4 Los Angeles abrasion (rock) 10

11.5 Unconfined comprehensive strength(rock)

40

11.6 Wet/ dry strength variation (rock) 10

11.7 Petrographic analysis (rock) 10


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Item No. Description Quantity Unit Rate Amount

11.8 Alkali reactivity 20

11.9 Particle shape and rock classification 10

11.10 10% fines 10

11.11 Bulk density 10

11.12 Aggregate crushing value 10

12.1 Concrete mix trials Lump sum

13.1 Hydraulic fracture and hydraulic jackingtests

Lump sum ....... .......

NN3 Site Investigations Spec

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