D-6: GLASS FIBER REINFORCED PLASTIC PIPES, SECTION: D-6D.6.1 GLASS FIBER REINFORCED PLASTIC PIPES

D.6.1.1 Scope

This specification covers requirements for materials, dimensions, classification, testing for pressure and non-pressure pipes made from glass fibre reinforced thermosetting resin with or without on aggregate filler. Specification also covers supplying, lowering, laying, joining and testing Glass-fibre Reinforced Plastic (GRP) pipes at work site used for the conveyance of industrial wastewater of highly acidic and corrosive nature.

D.6.1.2 Applicable Codes

a) National Standards

The manufacturing, testing, supplying, joining and testing at work site of GRP pipes shall comply with all currently applicable statues, regulations, standards and codes. In particular, the following standards unless otherwise specified here in, shall be referred. In all cases, the latest revision of the codes shall be referred to. If requirements of this specification conflicts with the requirements of the codes and standards, this specification shall govern.

(i) I.S. 14402 : 1996

Glass fiber reinforced plastics (GRP) pipes, joints and fittings for use forSewerage, Industrial waste & Water (other than potable)- specification

(ii) I.S. 12709 : 1989

Specification for glass fibre reinforced plastics (GRP) pipes for use for water supply and sewerage.

(iii) I.S. 6746 : 1972

Unsaturated, polyester resin systems for low pressure fibre reinforced plastics. (iv) I.S. 11273 : 1985Woven roving fabrics of E glass fibre. (v) I.S. 11320 : 1985Glass fibre roving for the reinforcement of polyester and of epoxide resin systems.

Sabarmati River front development Corporation Page 10 of 117(vi) I.S. 11551 : 1986

Signature of Bidder

Glass fibre chopped strand mat for the reinforcement of polyester resin systems.

b) International Codes

Wherever for certain specific requirements the information given in above mentioned IS codes is found to be inadequate, following international codes shall be referred to. However, in case of any discrepancy, decision of Owner / Engineer shall be final and implemented by the Contractor.

(i) ASTM D 2412 :

W Standard test method for determination of external loading characteristics of plastic pipe by parallel plate loading.

(ii) ASTM D 3262 :

Standard specification for reinforced plastic mortar sewer pipe. (iii) ASTM D 3517 :Standard specification for glass fibre reinforced thermosetting resin pressure pipe.

(iv) ASTM D 3618 :

Test for chemical resistance of reinforced thermosetting resin pipe in a deflected condition.

(v) ASTM D 3839 :

Standard practice for underground installation of flexible reinforced thermosetting resin pipe and reinforced plastic mortar pipe.

(vi) ASTM D 4161:

Standard specification for Fibre glass (glass-fiber reinforced thermosetting resin) pipe joints using flexible elastomeric seals.

(vii) ASTM D 477 :

Standard specification for elastomeric seals (Gaskets) for joining plastic pipe. (viii) ASNI/AWWA C 950-88AWWA standard for fiber glass pressure pipe.

D.6.1.3 Design and Pressure Rating

(a) Design

Design of GRP Pipes shall be in accordance with relevant clauses of IS 14402 and ASTM D 3262.

The materials sued shall be in accordance with the relevant clauses of IS : 6746, IS 14402, IS : 11320 and IS : 11551 and ASTM D 3262.

Other material such as aggregates like graded silica sand, filters, additives and colouring may be used as per specific requirements.

(b) Pressure Rating

GRP pipes used will be having pressure rating as follows :

Pressure class Working pressure rating(PN) (Pw) (Kpa)

3 300

6 600

9 900

12 1200

15 1500 (1 Kpa = 0.102 metres of Water column)

Note : The working pressure rating may be changed for use at fluid temperature greater than 43.5 deg. C in accordance with the manufacturers recommendation.

D.6.1.4 Manufacturing

(a) General

The method of manufacturing of GRP pipes shall be such that the form and the dimensions of the finished pipes are accurate within the limits specified in relevant Clauses of IS : 14402 and ASTM 3262. The surfaces and edges of the pipes shall be well defined and true and shall have squareness of pipe ends as specified in IS : 14402 and ASTM D 3262.

The GRP pipes and joints shall be systematically checked for any manufacturing defects by experienced supervisors so as to maintain a high standard of quality. Each pipe should have permanent ISI mark.

Owner/Engineer shall at all reasonable times have free access to the place where the pipes and joints are manufactured for the purpose of examining and testing the pipes and joints and of witnessing the test and manufacturing.

All tests specified either in this specification or in the relevant clauses of Indian Standards or International Standards shall be performed by Supplier/ Contractor at his own cost and in presence of Owner / Engineer if desired. For this, sufficient notice before testing of the pipes shall be given to Owner/ Engineer.

If the test is found unsatisfactory, Owner/Engineer may reject any or all pipes of that lot. The decision of Owner/Engineer shall be final and binding on Contractor and not subject to any arbitration or appeal.

(b) Dimensions

Pipes shall be designated by nominal standard diameters. The nominal diameters, minimum wall thickness, length of barrel, joints etc. shall be within the tolerance limits specified in IS: 14402, ASTM D 3262 and ASTM D 3517. The relevant requirements are specified in Data Sheet A.

(c) Workmanship and Finish

The inside surface of each pipe shall not have any visible defects such as bulges, dents, ridges foreign inclusion, cracks, crazing, pin holes and bubbles of 1.3 mm and above to the extent that it does not detrimentally affect the performance of the interior surface of the pipe wall.

Joint sealing surfaces shall be free of dents, gauges and other surface irregularities that will affect the integrity of the joints.

D.6.1.5 Structural Properties

(a) Specific initial ring stiffness

Each pipe length shall have sufficient strength to withstand the Class AA loading in addition to the over burden of back fill load upto the depth mentioned in data Sheet A above the crown of pipe. The minimum initial ring stiffness for withstanding above load conditions with maximum 5% of long term deflection shall be appropriately determined by manufacturer for actual execution.The stiffness class and minimum wall thickness required are specified in DataSheet-A.

(b) Beam Strength

The pipe shall meet or exceed the minimum longitudinal tensile / compressive strength as per relevant clauses of IS: 14402, ASTM D 4262 and ASTM D 3517.

(c) Hoop Tensile Strength

The pipes shall meet or exceed the minimum hoop tensile strength as per relevant clauses of IS: 14402, ASTM 3262 and ASTM D 3517.

D.6.1.6 Hydraulic Properties

(a) Soundness

Each length of pipe including specials shall withstand without leakage of cracking the internal hydrostatic proof pressures as per relevant clauses of IS:14402, ASTM D 3517. The hydrostatic test pressures are tabulated n DataSheetA. The site test pressure as required is also tabulated in Data SheetA.

D.6.1.7 Sampling and Inspection

In any consignment all the pipes of same class and size and manufactured under similar conditions of production shall be grouped together to constitute a lot. The conformity of a lot to the requirements of this specification shall be ascertained on the basis of tests on pipes selected from it.

Unless otherwise agreed upon between the purchaser and the supplier one lot shall consist of maximum of 100 m of each pressure class, stiffness class and size of pipe produce.

Pipes shall be selected at random. In order to ensure randomness, all the pipes in the lot may be arranged in a serial order and starting from any pipe, every r the pipe be selected till the requisite number is obtained, r being the integral part of N/n where N is the lot size and n is the sample size. The scale of sampling shall be as per following table.

SCALE OF SAMPLING AND PERMISSIBLE NUMBER OF DEFECTIVES

No. of pipes inThe lotFor Requirements underClause 1.5 & 1.6Sample size for tests under Clause 1.8

Sample Size(No. of Pipes)Permissible number ofdefectives(No. of Pipes)

(N)(n)(n)

Upto 50802

51 to 1001313

Each pipe shall be checked for dimensions, soundness, workmanship finish and deviation from straight.

The lot shall be declared as conforming to the requirements of this specification, if the sample pipes taken from the lot meets the requirements of all the tests, otherwise no t.

Testing

GRP pipes manufactured by the above process shall be subjected to the following tests.

(a) Testing of pipe at factory

After selecting pipe specimens randomly from the lot as per clause no. 1.7 above they shall be tested at factory for following tests.

(b) Critical dimensions

All pipes will be measured for compliance with critical dimensions as specified in relevant clauses of IS : 14407, ASTM D 3262 and ASTM D 3517 after allowing for the specified tolerances. The dimensions shall include diameter, wall thickness, sqareness and length. Pipes not in compliance will be rejected.

(c) Visual Acceptance

Generally the pipe shall be free from all defects, including de-laminations, bubbles, pinholes, cracks, pits, blisters, foreign inclusions and resin-starved areas that due to their nature, degree or extent, detrimentally affect the strength and serviceability of the pipe. The pipe shall be as uniform as commercially practicable in colour, capacity, density and other physical properties.

(d) Tests for Specific Initial Ring Stiffness (SIRS)

Pipe ring samples shall be taken as per 4.6.2 from each diameter manufactured and tested for SIRS as per relevant clauses of IS : 14407, ASTM D 2412 and ASTM D 3517.

If a pipe sample from a lot fails to met the required stiffness, a further two samples shall be tested from that lot. If they both pass, the lot will be accepted. If they fail Pipes will be tested on an individual basis and only pipes which pass will be accepted.

(e) Hydrostatic Soundness Test

The manufacturer shall hydrostatically test pipes by hydrostatic proof test in accordance with the relevant Clause of IS : 14407 and ASTM D-3517. The procedure should be as follows :

Each length of pipe, shall be placed in a hydrostatic pressure test machine which seals the ends and exert no end loads. The pipe shall be filled with water, expelling all air and an internal water pressure shall be applied at a uniform rate not to exceed 300 Kpa/S until the test pressure of two times the pressure class is reached. This pressure shall be maintained for one minute. The pipe shall show no visual signs of weeping leakage or fracture of the structural wall. Integral bells, including reinforcement sleeves, if any, or affixed coupling shall be tested with the pipe. Any pipes failing to pass this test will be rejected. Rejected pipes may be repaired and retested, if they pass, they will then be accepted.

(f) Beam Strength Test

The manufacturer shall test the pipe for longitudinal tensile strength as per the relevant clauses in IS : 14407, ASTM D 2412, ASTM D 3262 and ASTM D

3517. The sample size shall be selected as per clause 1.7 above. If may sample should fail to meet the requisite value specified in the IS/ASTM codes, five (5) further samples should betaken and tested. If the results comply with requirement, all pipes will then be acceptable. However, if these five samples fail then all pipes from that lot will be rejected unless individually proven acceptable.

(g) Hoop Tensile Strength

The manufacturer shall test the pipe for hoop tensile strength as per relevant clauses in IS : 14407, ASTM D 3262, ASTM D 3517. The sample size shall be selected as per clause no. 1.7 above. Every sample piece should meet or exceed the hoop tensile strength specified in IS : ASTM codes. If any sample fails to meet the requisite value five (5) further samples shall be taken and tested. IF the results comply with requirement, all pipes will then be acceptable. However, if these five samples fail then all pipes from that lot will be rejected unless individually proven acceptable. Rejected pipes will, however, be acceptable for use at a lower working pressure as per the criteria stated in the specification.

(h) Long Term Hydrostatic Strain Test

The pressure as classes as given in relevant clause shall be based on long term hydrostatic design pressure data obtained as per relevant clauses of IS : 14407, ASTM D 3262 and ASTM D 3517. For those products where no previous long term hydrostatic testing has been performed on similar products the full type testing shall be carried out to define design pressure classes based on extrapolated strengths at 50 years. When a hydrostatic design basis has already been established for a nominally similar pipe using the same manufacturing process, the manufacturer need only conduct the re-qualification test as described in the relevant clauses of IS : 12709.

(i) Test Certificate for Chemical resistance of GRP Pipes in a deflectedCondition

The manufacturer / supplier / contractor shall produce a test certificate for chemical resistance of GRP pipes in a deflected condition that when installed within 5% deflection the pipes will last over 60 years under highly acidic and corrosive condition and stand guarantee for the same. For waste water characteristics the relevant reports / documents available with owner shall be referred, if required.

D.6.1.8 Marking

Both ends of each length of pipe and fitting shall be marked at least in letters not less than 12 mm in height and of bold type style in a colour and type that remains legible under normal handling and installation procedures. The marking shall include the following :(a) Internal diameter

(b) Class of pipe (pressure and stiffness) (c) Date of manufacture(d) Name of manufacturer or his registered trade mark or both(e) Nominal thickness

All pipes and fittings shall have ISI mark.

D.6.1.9 Handling

The manufacturer / Supplier (M/S) shall be responsible for safe delivery of pipes and fittings as per order place and as per the schedule. If the contractor for works is other than manufacturer / supplier, then M/s shall submit a complete manual of instruction/ guide./ procedure for handling of pipe before installation. Broadly following instructions/ procedures shall be followed.

D.6.1.10 Fire Safety

GRP pipes manufactured using petrochemicals and are inflammable. Hence manufacturer/supplier/contractor (m/s/c) shall take utmost precaution while handling, transporting, storing, loading/unloading, installing, and testing, etc. at all stages, against fire hazard. Care must be taken to avoid exposure of the pipe to welders sparks, cutting-torch flames or other heat / flame / electrical sources which could ignite the pipe material.

D.6.1.11 Transportation

All pipe sections shall be supported on flat timbers spaced on a maximum of 4 mete rs centres with a maximum overhand of 2 metres in trucks. No pipes shall be in contact with other pipes while transportation.

Maximum stack height will be approximately 2 meters. Pipes shall be strapped to the vehicle over the support points using pliable straps or ropes, Steel cables or chains shall not be allowed for strapping without adequate padding, stacking pipes shall limit the deflection as follows:

3.0% o9f diameter for stiffness class SN 1250.2.5% of diameter for stiffness class SN 25002.0% of diameter for stiffness class SN 50001.5% of diameter for stiffness class SN 10000

D.6.1.12 Storing

Pipes may be stored on ground or on flat timbers. When storing on ground the ground shall be flattened and made free of potential damaging debris. All pipes shall be choked to prevent rolling.

If it is necessary to stack pipes, flat timber supports at maximum 6 metre spacing with chocks shall be used. If it is available, the original shipping dunnage shall be used. The stacks shall be stable against wind or other horizontal forces. Maximum stack height allowable shall be approximately 2 metres. Pipes larger than 1400 mm diameter shall not be stacked. The permissible deflection shall be as per clause 1.15.

Rubber ring gasket shall be shipped separately from the couplings and shall be stored in the shade in their original packaging and shall not be exposed to sunlight except during utilisation. The gaskets shall also be protected from exposure to greases and oils which are petroleum derivatives and from solvents and other deleterious substances.

Gasket lubricant shall be carefully stored to prevent damage to the container. Partially used buckets shall be prevented from contamination of the lubricant.

D.6.1.13 Unloading, lifting and lowering

Adequate control shall be ensured during unloading and lifting of pipes with guide ropes attached to pipes or packages. Spreader bars shall be sued when multiple locations are necessary. The pipes shall not be dropped to avoid impact or bump, particularly at pipe ends.

Non-utilised stack of pipes shall not be handled a single bundle. Non-utilised pipes shall be handled separately, one at a time. Pipes shall be handled or lifted with pliable straps, slings or ropes. Steel cables or ropes shall not be used for lifting and transportation of pipe. Ropes shall not pass through the section of pipe, end to end.

If any time during handling or installation of pipe, any damage, such as gouge, crack or fracture occurs, the pipe shall be repaired or replaced as directed by Owner / Engineer before installation.

D.6.1.14 Jointing Pipes

Pipe sections shall be jointed utilising double bell couplings and shall be assembled as indicated in the following paragraphs and as per the relevant clauses of ASTM D3517, STM D 4161. The gasket used for jointing purpose shall be as per ASTM F447, specification for Elastomeric Seals (gasket) for joining plastic pipes.

(a) Clean Coupling

Double bell coupling grooves and rubber gasket ring shall be thoroughly cleaned to make sure no dirt or oil is present.

(b) Install Gaskets

The gasket shall be inserted into the grooves, leaving two to four uniform loops of rubber extending out of the groove. There should be a minimum of one loop for each 450 mm of gasket ring circumference.

(c) Lubricate Gaskets

Uniform pressure shall be applied to push each loop of the rubber gasket into the gasket groove. Then using a clean cloth, a thin film of lubricant shall be applied to the rubber gasket. Normal amount of lubricant consumed per joint shall be as follows :

600 - 800 mm dia. - 0.1 Kg900 - 1000 mm dia. - 0.15 Kg1100 - 1200 mm dia. - 0.20 Kg1300 - 1400 mm dia. - 0.25 Kg1500 - 1600 mm dia. - 0.30 Kg1800 mm dia. - 0.35 Kg

(d) Clean and Lubricate Spigots

Pipe spigots shall be thoroughly cleaned to remove any dirt, grit, grease, etc. Using a clean cloth, a thin film of lubricant shall be applied to the spigots from the end of the pipe to the black positioning stripe.

(e) Fixing of Clamps

The first clamp is fixed anywhere on first pipe or left in position from previous joint. The second clamp is to be fixed on the pipe to be connected in the correct position relative to the alignment stripe on the spigot end so as also to act as a stopper. Clamp contact with the pipe shall be padded or otherwise protected to prevent damage to the pipe and have high friction resistance with the pipe surface. Care shall be taken in the alignment of the coupling.

(f) Pipe Placement

The pipe to be connected shall be placed on the bed with sufficient distance from the previously joined pipe to allow lowering the coupling into position.

(g) Join Coupling

Come along jacks shall be installed to connect the pipe clamps and two 10 cm x10 cm timbers or similar (large diameters may require a bulkhead) are placed between the pipe previously connected and the coupling. While these are held inposition, the new pipe shall be entered into the coupling until it rests against thesecond pipe clamp. Come-along jack might need protective plank in order not to rub against the pipe.

(h) Join Pipes

Come along jacks shall be loosened and the timbers removed before retightening the jacks for entering the coupling onto the previously connected pipe. Correct position of the edge of the coupling to the alignment stripe home line shall be checked.

(i) Angular Deflection

Maximum angular deflection (turn) at each coupling joint shall not exceed the amounts given below. Also the pipes should be joined in straight alignment and thereafter deflected angularly if necessary.

Nominal Angular Deflection at Double Bell Coupling Joint

Pipe diameter(mm)Nom.Angular deflection (Degrees)Nom. Offset (mm)Nom. Radius ofCurvature (m)

Section LengthsSection Length

3 m6 m12 m3 m6 m12 m

300 to 6003.015731462857115229

700 to 8002.513126252369137275

900 to 10002.010520941986172344

1100 to 13001.579157314115229458

1400 to 16001.2565131262138275550

1800 to 24001.0052105209172344688

(j) Layup Joints

The manufacturer / tenderer shall provide full details of the layup joints and polymer resin which will be used for connection of pipes to manholes.

(k) Joining pipes with different wall thickness

When two pipes of same diameter but of different wall thickness are required to be joined at site, the contractor is required to execute the joint very precisely so as to have straight alignment of pipe inverts.

D.6.1.15 Pipe Bedding and Backfilling

(a) Pipe Bedding

The pipe bedding zone starts from the bottom of trench to the invert level of pipe. This depth varies with pipe diameter but shall be a minimum of 150 mm thick layer of granular material not greater than 10 mm in size.

Pipe bedding material shall be sand or gravel as per the requirements of the backfill materials and the same as that utilized for select material in the remainder of the pipe zone. The bedding shall be compacted to a minimum 90% Standard Proctor Density (70% of maximum relative density for crushed rock, crushed stone and gravels). The finished bed shall be plane. The minimum depth shall be 1/4th the diameter (minimum 150 mm) and shall provide uniform and continuous support for the pipe. Prior to pipe placement, the compacted bed shall be slightly loosened at the invert location to a depth 25 to 50 mm so the pipe, when positioned into the trench, will seat well into the bed. The bed shall be over excavated at each coupling (joint) location to ensure that the pipe will have continuous support. The pipe shall not rest on the coupling for support. Howeve r,

it shall be assured that the coupling area is properly bedded and backfilled after the joint assembly is completed.

(b) Backfilling Pipe

Backfilling shall be done immediately after joining pipes. Proper selection, placement and compaction of pipe zone backfill shall be ensured to control the vertical deflection. Installed pipes shall have initial deflection less than the values to be given by the tenderer depending on the type of soil to encountered with, the pipes shall have no bulges, flat areas, or other abrupt changes of curvature.

(c) Pipe Zone Backfill

Pipe zone for backfilling shall be defined as the zone from the bed upto 300 mm above the pipe crown.

Most coarse grained soils are acceptable. This shall be composed of gravel or clean sand. However, silty sand, clayey sand, silty gravel and clayey gravel shall not be used unless proposed to be used in conjunction with gravel or clean sand. The selection of backfill material would require the approval of the Engineer -in- charge.

Compatibility of the backfill material and the native soil shall be checked. Sieve analysis shall be carried out at selected sections to ensure that between two adjacent soils D85 finer is grater than 0.2 D15 coarser where D85 percentile size of finer soil and D15 is the 15 percentile size of coarser soil.

Where native soil is shown in the pipe zone the soil shall be granular, free of debris and organic materials and rocks and soil clumps grater than 2 times the maximum gravel size.

Maximum size of grain for the backfill material shall be : Upto 1600 mm dia. 19 mmFor 1800 mm to 2400 mm dia. 25 mm

Backfill shall not be onto the pipe from the top of the trench. During backfilling, it shall be made certain that the granular material flows completely under the pipe to provide full support. A board or other blunt toll may be used to push and compact the backfill under the pipe. Proper completion of this step is a very important phase of backfilling the pipe.

Proper backfilling shall be done in 150 mm to 300 mm lifts, depending on backfill material and compaction method. Between each lift. The proper compaction shall be attained to ensure that the pipe will have adequate side support. Compaction of sandy (Vs. Gravel) backfill is accomplished most easily when the material is at or near its optimum moisture content. When backfilling reaches pipe spring line (half of diameter), all compaction shall be done first near the trench sides and proceed towards the centre.

Initial vertical ovalization shall not exceed 3% of diameter. This measurement shall be determined when backfilling reaches pipe crown.

All lifts with a specified density must be properly compacted. Care must be taken to avoid excessive compactive effort above the pipe crown, to avoid bulges or flat areas, however, the material in this area shall not be left loose.

D.6.1.16 Alternate Installations

When the combination of pipe stiffness, cover depth, and native soil characteristics places the installation required in the alternate category, following options are available.

1) Use a higher stiffness pipe to permit a standard installation.2) Increase the trench widthThe specific requirement for standard and alternate installation are given in DataSheet A.

D.6.1.17 Unstable Trench Bottom

Where the trench bottom has soft, loose, or highly expansive soils, the trench bottom shall be regarded as unstable. An unstable trench bottom shall be stabilised before laying pipe, or a foundation must be constructed to minimise differential settlement of the trench bottom. The engineer-in-charge may elect, depending upon the severity of the unstable soil, to require special foundations by stabilisation of the bottom material; or by over excavation and replacement with a foundation and bedding of processed gravel, suitably grades, and impervious to infiltration or migration of the unstable soil. The depth of the stone or gravel material used for foundation will depend upon the severity of the trench bottom soil conditions, but shall be a minimum of 150 mm. the normal bedding shall be placed on top of any foundations.

Foundations and bedding materials shall be selected to avoid migration of one into the other that could cause loss of pipe bottom. Additionally, the maximum allowable pipe section length between flexible joints shall be 6 meters.

D.6.1.18 Flooded Trench

When the ground water table is above the trench bottom, the water level shall be lowered to at least the trench bottom (preferably about 200 mm below) prior to preparation of the pipe bed. If the water level can not be maintained below the top of the bedding, special installation methods shall be adopted at no extra cost to achieve proper pipe support. Specification of an appropriate procedure shall require the approval of Engineer-in-charge. If the pipe is empty in a flooded trench, a minimum cover of one pipe diameter of dense soil (1,900 kg/cu.m. or more) will be normally sufficient to prevent pipe flotation.

D.6.1.19 Dewatering the Trench

The following cautions shall be taken when dewatering

-Avoid pumping long distances through the backfill materials or native soils, which could cause loss of support to previously installed pipes due to removal of material or migration of soil.

-Do not turn off the dewatering system until sufficient cover depth has been reached to prevent pipe flotation.

D.6.1.20 Use of Temporary Trench Shoring

If at all possible the use of trench shoring or sheeting at pipe level should be avoided. In case where shoring or sheeting are necessary and can not be avoided, the following requirements must be met :

(a) Alternative 1Install the shoring to a depth of 300 mm above the top of the pipe, leaving the native trench sides fully exposed at pipe level.

(b) Alternative 2Use sheeting which will last the life of the pipeline, and leave the sheetingpermanently in position. (The sheeting may be cut off 300 mm above top of pipe and the upper sections extracted, is so desired).

Native Soil Classification & Allowable Initial Deflection

Soil Group1234

CohesiveHard & VeryStiffStiffMediumSoft

GranularVery Dense& DenseMediumLooseVery Loose

Blow Count3016-306-153-5

Allowable initialinstalled deflection of %Diameter3.03.02.52.0

Checking to insure that the above initial requirements MUST be done for each pipe immediately after completion of installation (typical within 24 hours after reaching maximum cover).

While initial deflection in Table above area acceptable for pipe performance, a value more than 2% indicates the installation intended has not been achieved and shall be improved for future pipes (i.e. increased pipe zone backfill compaction, coarser grained pipe zone backfill materials, or wider trench etc.

Following procedure shall be adopted for checking the initial diametrical deflection for installed pipes :

Complete backfilling shall be done to require grade.

The temporary sheeting (if used) shall be completely removed.

The dewatering system (if used) shall be turned off.

The pipes vertical diameter shall be measured and recorded.

Note : For small diameter pipes, a VEROC delfectometer or similar device may be pulled through the pipes to measure the vertical diameter.

The vertical deflection shall be calculated as follows :-

% deflection = Actual I. D. Installed Vertical I. D. x 100Actual ID

Compare deflections to acceptable values as defined in Clause 8.1.

Deflection checks shall be done when the first installed pipes have been backfilled to grade and continued periodically throughout the entire project. Laying shall not get too far ahead before verifying the installation quality. This will ensure early detection and correction of inadequate installation methods and keep to a minimum the number of inadequately installed pipes.

Pipes installed with initial deflections exceeding the values in Clause 8.1 shall be reinstalled so the initial deflection is less than those values. Clause 8.4 Correcting Over Deflected Pipe, for limitations applicable to this work shall be followed.

Actual I. D. may be verified or determined by measuring the diameters of a pipe laying loose (no pipes stacked above) on a reasonable plane surface, as follows.

Actual I. D. = Vertical I. D. + Horizontal I. D.2OR

Actual I. D. = I. D. (1) + I. D. (2)2

D.6.1.21 Correcting Overdeflected Pipe

Pipes installed with initial diametrical deflections exceeding the values in Clause1.22 shall be corrected to ensure the long term performance of the pipe.

(a) For Pipe Deflected upto 8% of Diameter :

Excavate to near the pipe invert / haunch depth. Excavation just above and at the sides of the pipe should be done utilizing hand tools to avoid impacting the pipe with heavy equipment.

Inspect the pipe for damages. Damaged pipe should be repaired or replaced as directed by the Owner / Engineer.Re-compact haunch backfill, ensuring it is not contaminated with the native soil.

Re-backfill the pipe zone in lifts with the appropriate material, compacting each layer ad required by the cover depth to limit the pipe deflection.

Backfill to grade and check the pipe deflections to verify they have not exceeded the values in Clause 8.1.

(b) For Pipe Deflected Greater than 8% Pipe Diameter

Pipes over 8% deflections shall be replaced completely.

No attempt to jack or wedge the installed over-deflected pipe into a round condition shall be made to avoid damage to the pipe.

D.6.1.22 Field Hydro Testing for Water Tightness

Completed pipeline inclusive of manholes shall be hydrostatically tested for water tightness prior to acceptance and service. It shall be done regularly as installati on proceeds.

Installation should never exceed testing by more than 1 Km.

After the joints have thoroughly set and have been checked by Owner / Engineer and before backfilling the trenches the entire section of laid pipeline shall be tested for water tightness by filling in pipes with water to the level of 1.5 M above the top of the highest pipe in the stretch. The heading of water shall be retained for 1.0 hour. If any leakage is detected it shall be repaired and retested for no leak. IF required by Owner / Engineers, the contractor shall dewater the excavated pit / trench and keep id dry during the period of testing.

The testing of manholes for water tightness shall be carried out by complete filing of the manhole with water and the loss of water shall not exceed 2.0 lit / hr / m height of manhole.

All equipment for testing at work site shall be supplied and erected by Contractor. Water for testing of pipeline shall be arranged by Contractor. Damage during testing shall be contractors responsibility and shall be rectified by him to the full satisfaction of Owner / Engineer. Water used for the test shall be removed form the pipes and not released to the excavated trenches.

D.6.1.23 Concrete Encasement

When encasement of pipes in concrete has been specified to carry unusual loads, specific limitations in the installation procedures shall be observed.The concrete surround must be placed stages allowing sufficient time layers for the cement to set (no longer exert buoyant forces). Maximum lift height is variable with nominal pipe stiffness as shown below :

SN 1250 & SN 2500 - Not more than 300 mm or D/4 whichever is larger SN 5000 - Not more than 450 mm or D/3 whichever is larger SN 10000 - Not more than 600 mm or D/2 whichever is largerD.6.1.24 Measurement

All GRP pipes shall be measured according to the work actually done and no allowance will be made for any waste in cutting to the exact length required. The measurement for pipes shall be in running meters nearest to a centimeter of length along the centre line of pipe as actually laid at work site.

The rate for providing, lowering, laying and jointing of GRP pipes and fittings shall be deemed to include cost of joining material such as couplings, gaskets, lubricants, equipment and tools for making joints, testing as specified and as directed and the extra excavation required for bedding of pipes and fittings / couplings etc.

DATA SHEET A

(1)Pressure Class required :PN 6 Bar

(2)Working pressure rating :6 kPa = 61.2 m wc

(3)Hydrostatic test pressure :12 kPa = 122.4 m wc

(4)Site test pressure :As per Clause 1.24

(5)Length of barrel or each pipe length :12.0 m

(6)Stiffness class and depth of cover :

Stiffness Class stiffnessKPA.Maximum depth of coverm

D 24812

(7) Minimum wall thickness : 30 mm

(8) Joints

The GRP pipes shall be joined by utilizing Double Bell Couplings.

In special cases as per the manufacturer / suppliers instructions the following types of joints may be allowed by Owner / Engineer.a) Flexible steel coupling with anyone of i) Epoxy or PVC coated steel mantle ii) Stainless steel mantle, or

iii) Hot dip galvanised steel mantle

b) Mechanical steel couplings and/or c) Lay-up joints

(9) Width of trench (Bt) from the invert level of pipe upto ground level above the top of pipe. Width of trench shall be as per drawing given in tender document.

(11)Bedding and backfilling for pipes: As per Clause 1.16.

D.6.5 CONNECTION WITH EXISTING TRUNKS

D.6.5.1 It will be necessary to give connections of the new 2000 mm dia. GRP pipes with Existing manhole near Ambedkar Bridge East side near pumping station.The connection will be made with all jointing materials etc. complete. The payment will be made on item completed as stated above.

Specification for installing Glass Fiber Reinforced Plastics (GRP) pipes

2901. SCOPE

This work shall consist of furnishing and installing Glass Fiber Reinforced Plastics (GRP) pipes, Joints and Fittings for use for sewerage, industrial Waste and water other than portable water conforming to IS 14402-1966 of the type, diameter and length required at the locations shown on the drawings or as ordered by the Engineer and in accordance with the requirements of these Specifications.

2902. MATERIALS

All materials used in the manufacturing and laying of pipes shall conform to Glass Fiber Reinforced Plastics (GRP) pipes, Joints and Fittings for use for sewerage, industrial Waste and water other than portable water conforming to IS 14402-1966

Each consignment of GRP pipes shall be inspected, tested, if necessary, and approved by the Engineer either at the place of manufacture or at the site before their incorporation in the works.

2903. EXCAVATION FOR PIPE

The foundation bed for laying of pipes shall be excavated true to the lines and grades shown on the drawings or as directed by the Engineer. The pipes shall be placed in shallow excavation of the natural ground or in open trenches cut in existing embankments, taken down to levels as shown on the drawings. In case of high embankments where the height of fill is more than three times the external diameter of the pipe, the embankment shall first be built to an elevation above the top of the pipe equal to the external diameter of the pipe, and to width on each side of the pipe of not less than five times the diameter of pipe, after which a trench shall be excavated and the pipe shall be laid.

Where trenching is involved, its width on either side of the pipe shall be a minimum of150 mm or one-fourth of the diameter of the pipe whichever is more and shall not be more than one-third the diameter of the pipe. The sides of the trench shall be as nearly vertical as possible.

The pipe shall be placed where the ground for the foundation is reasonably firm. Installation of pipes under existing Drain, structure or culverts shall be avoided as far as possible. When during excavation the material encountered is soft, spongy or other unstable soil, andunless other special construction methods are called for on the drawings or i n special provisions, such unsuitable material shall be removed to such depth, width and length as directed by theEngineer. The excavation shall then be backfilled with approved granular material which shall be properly shaped and thoroughly compacted up to the specified level.

Where bed-rock or boulder strata are encountered, excavation shall be taken down to at - least 200 mm below the bottom level of the pipe with prior permission of the Engineer and all rock/boulders in this area be removed and the space filled with approved earth, free from stone or fragmented material, shaped to the requirements and thoroughly compacted to provide adequate support for the pipe.

Trenches shall be kept free from water until the pipes are installed and the joints have hardened.

2904. BEDDING FOR PIPE

The bedding surface shall provide a firm foundation of uniform density throughout the length of the pipe, shall conform to the specified levels and grade, and shall be as specified here:

First Class bedding: Under first class bedding, the pipe shall be evenly bedded on a continuous layer of well compacted approved granular material, shaped concentrically to fit the lower part of the pipe exterior for atleast ten per cent of its overall height or as otherwise shown on th e drawings. The bedding material shall be well graded sand or another granular material passing5.6 mm sieve suitably compacted/rammed. The compacted thickness of the bedding layer shall be as shown on the drawings and in no case shall it be less than 75 mm.

2905. LAYING OF PIPE

No pipe shall be laid in position until the foundation has been approved by the Engineer. Where two or more pipes are to be laid adjacent to each other, they shall be separated by a distance equal to at least half the diameter of the pipe subject to a minimum of 450 mm.

The arrangement for lifting, loading and unloading concrete pipes from factory/yard and at site shall be such that the pipes do not suffer any undue structural strain, any damage due to fall or impact. The arrangement may be got approved by the Engineer.

Similarly, the arrangement for lowering the pipe in the bed shall be got approved by the Engineer. It may be with tripod-pulley arrangement or simply by manual labour in a manner that the pipe is placed in the proper position without damage.

The laying of pipes on the prepared foundation shall start from the outlet and proceed towards the inlet and be completed to the specified lines and grades. In case of use of pipes with bell-mouth, the belled end shall face upstream. The pipes shall be fitted and matched so that when laid in work, they form a uniform gradient with a smooth uniform invert.

Any pipe found defective or damaged during laying shall be removed at the cost of theContractor.

2906. JOINTING

The pipes shall be jointed either by collar joint or socket spigot joint. In the former case, the collars shall conform to IS 14402-1966 and having the same strength as the pipes to be jointed. Jointing and Gluing space shall conform to various standards laid in Indian standard as well as British standards according to the diameter of the pipe

Sabarmati River front development Corporation Page 20 of 117For jointing pipe lines under light hydraulic pressure, the recess at the end of the pipe shall be filled with suitable approved compound. Pipes shall be so jointed that the ring of one pipe shall set into the recess of the next pipe.The ring shall be thoroughly compressed by jacking or by any other suitable method.

All joints shall be made with care so that their interior surface is smooth and consistent with the interior surface of the pipes. After finishing, the joint shall be kept covered and damp for at least four days.

2907. BACKFILLING

Trenches shall be backfilled immediately after the pipes have been laid and the jointing material has set. The backfill soil shall be clean, free from boulders, large roots, excessive amounts of sods or other vegetable matter, and lumps and shall be approved by the Engineer. Backfilling up to 300 mm above the top of the pipe shall be carefully done with approved graded gravelly material and the soil thoroughly rammed, tamped or vibrated in layers not exceeding 300 mm, particular care being taken to thoroughly consolidate the materials under the haunches of the pipe. Approved pneumatic or light mechanical tamping equipment can be used.

Filling of the trench shall be carried out simultaneously on both sides of the pipe in such a manner that unequal pressures do not occur.

In case of high embankment, after filling the trench up to the top of the pipe in the above said manner, a loose fill of a depth equal to external diameter of the pipe shall be placed over the pipe before further layers are added and compacted.

2908. MANHOLES AND OTHER ANCILLARY WORKS

Manholes and other ancillary works shall be constructed in accordance with the details shown on the drawings or as directed by the Engineer.

2909. OPENING TO TRAFFIC

No traffic shall be permitted to cross the pipe line unless height of filling above the top of the pipe line is at least 1200 mm.

2910. MEASUREMENTS FOR PAYMENT

Glass Fiber Reinforced Plastics (GRP) pipes shall be measured along their centre between the inlet and outlet ends in linear meters.

Selected granular material for pipe bedding shall be measured as laid in cubic meters. Ancillary works like Construction of manholes etc., shall be measured as provided for under the respective Sections.

2911. RATE

The Contract unit rate for the installing Glass Fiber Reinforced Plastics (GRP) pipes shall include the cost of pipes including loading, unloading, hauling, handling, storing, laying in position and jointing complete and all incidental costs to complete the work as per these Specifications.

Ancillary works such as excavation including dewatering & backfilling, concrete and masonry shall be paid for separately, as provided under the respective Clauses.

Detailed Technical Specifications for FRP ManholesThe FRP Manholes Shall be constructed, tested and installed as per the Standards/methodmentioned in the attached sheets and drawings.

The wall thickness will be as per the drawing attached. Manhole shall be able to withstand the load of heavy trucks as they are to be laid below the road having heavy traffic. Contractor has to give guarantee for that.

Proper base to receive the prefabricated manhole shall be prepared by the contractor as the instructions given in the sheet.

The joints of pipes and manholes shall be made leak proof using resins and fibers .The resin and fiber shall be sustainable to industrial effluent. The effluent standards are given in Annexure-A.

Required Concrete work shall be done on top of manhole to fix the manhole seat and cover and match with existing ground level/road level.

304. EXCAVATION FOR LAYING PIPES

304.1. Scope

Excavation for pipe laying shall consist of the removal of material for the laying pipe and Manholes & other similar structures, in accordance with the requirements of these Specifications and the lines and dimensions shown on the drawings or as indicated by the Engineer. The work shall include construction of the necessary cofferdams and cribs and their subsequent removal; all necessary sheeting, shoring, bracing, draining and pumping; the removal of all logs, stumps, grubs and other deleterious matter and obstructions, necessary for laying pipes, placing the foundations; trimming bottoms of excavations; backfilling and clearing up the site and the disposal of all surplus material.

304.2. Classification of Excavation

301.2.

All materials involved in excavation shall be classified in accordance with Clause

304.3 Construction Operations

304.3.1 Setting out: After the site has been cleared according to Clause 201, the limits of excavation shall be set out true to lines, curves and slopes to Clause 301.3.1.

304.3.2.Excavation: Excavation shall be taken to the width of the lowest stepof the footing and the sides shall be left plumb where the nature of soil allows it. Where the nature of soil or the depth of the trench and season of the year do not permit vertical sides, the Contractor at his own expense shall put up necessary shoring, strutting and planking or cut slopes to a safer angle or both with due regard to the safety of personnel and works and to the satisfaction of the Engineer.

The depth to which the excavation is to be carried out shall be as shown on the drawings, unless the type of material encountered is such as to require changes, in which case the depth shall be as ordered by the Engineer. Propping shall be undertaken when any foundation or stressed zone from an adjoining structure is within a line of 1 vertical to 2 horizontal from the bottom of the excavation.

Where blasting is to be resorted to, the same shall be carried out in accordance with Clause 302 and all precautions indicated therein observed. Where blasting is likely to endanger adjoining foundations or other structures, necessary precautions such as controlled blasting, providing rubber mat cover to prevent flying of debris etc. shall be taken to prevent any damage.

304.3.3 Dewatering and protection: Normally, open foundations shall be laid dry. Where water is met with in excavation due to stream flow, seepage, springs, rain or other reasons, stagnant water of river sabarmati the Contractor shall take adequate

measures such as bailing, pumping, constructing diversion channels, drainage channels, bunds, depression of water level by well-point system, cofferdams and other necessary works to keep the foundation trenches dry when so required and to protect the green concrete/masonry against damage by erosion or sudden rising of water level. The methods to be adopted in this regard and other details thereof shall be left to the choice of the Contractor but subject to approval of the Engineer. Approval of the Engineer shall, however, not relieve the Contractor of the responsibility for the adequacy of dewatering and protection arrangements and for the quality and safety of the works.

Where cofferdams are required, these shall be carried to adequate depths and heights, be safely designed and constructed and be made as watertight as is necessary for facilitating construction to be carried out inside them. The interior dimensions of the cofferdams shall be such as to give sufficient clearance for the construction and inspection and to permit installation of pumping equipments etc., inside the enclosed area.

If it is determined beforehand that the foundations cannot be laid dry or the situation is found that the percolation is too heavy for keeping the foundation dry, the foundation concrete shall be laid under water by tremie pipe only. In case of flowing water or artesian springs, the flow shall be stopped or reduced as far as possible at the time of placing the concrete.

Pumping from the interior of any foundation enclosure shall be done in such a manner as to preclude the possibility of the movement of water through any fresh concrete. No pumping shall be permitted during the placing of concrete or for any period of at least 24 hours thereafter, unless it is done from a suitable sump separated from the concrete work by a watertight wall or other similar means.

At the discretion of the Contractor, cement grouting or other approved methods may be used to prevent or reduce seepage and to protect the excavation area.

The Contractor shall take all precautions in diverting channels and in discharging the drained water as not to cause damage to the works, crops or any other property.

304.3.4.Preparation of foundation: The bottom of the foundation shallbe levelled both longitudinally and transversely or stepped as directed by the Engineer. Before pipe is laid, the surface shall be slightly watered and rammed. In the event of excavation having been made deeper than that shown on the drawings or as otherwise ordered by the Engineer, the extra depth shall be made up with concrete or masonry of the foundation at the cost of the Contractor as per Clause 2104.1. Ordinary filling shall not be used for the purpose to bring the foundation to level.

304.3.5. Slips and slip-outs: If there are any slips or slip-outs in the excavation, these shall be removed by the Contractor at his own cost.

304.3.6. Public safety: Near towns, villages and all frequented places, trenches and foundation pits shall be securely fenced, provided with proper caution signs and marked with red lights at night to avoid accidents. The Contractor shall take adequate protective measures to see that the excavation operations do not affect or damage adjoining structures. For safety precautions, guidance may be taken from IS : 3764.

304.3.7. Backfilling: Backfilling shall be done with approved material after concrete or masonry is fully set and carried out in such a way as not to cause undue thrust on any part of the structure. All space between foundation masonry or concrete and the sides of excavation shall be refilled to the original surface in layers not exceeding 150 mm compacted thickness. The compaction shall be done with the help of suitable equipment such as mechanical tamper, rammer, plate vibrator etc., after necessary watering, so as to achieve a density not less than the field density before excavation.

304.3.8. Disposal of surplus excavated materials: Clause 301.3.11 shall apply.

304.4.Measurements for Payment

Excavation for laying of pipes and manhole shall be measured in cu. m. for each class of material encountered, limited to the dimensions shown on the drawings or as directed by the Engineer, Excavation over increased width, cutting of slopes, shoring, shuttering and planking shall be deemed as convenience for the Contractor in executing the work and shall not be measured and paid for separately.

Foundation sealing, dewatering, including pumping is included in the above rates and will not be paid separately.

304.5 Rates

304.5.1. The Contract unit rate for the items of excavation for structures shall be payment in full for carrying out the required operations including full compensation for :

(i) setting out;

(ii) construction of necessary cofferdams, cribs, sheeting, shoring and bracing and their subsequent removal;

(iii) removal of all logs, stumps, grubs and other deleterious matter and obstructions, for placing the foundations including trimming of bottoms of excavations;

(iv) foundation sealing, dewatering including pumping as no separate provision for it is made in the Contract;

(v) backfilling, clearing up the site and disposal of all surplus material within all lifts and leads up to 2000 m or as otherwise specified; and

(vi) all labour, materials, tools, equipment, safety measures, diversion of traffic and incidentals necessary to complete the work to Specification.

304.5.2. Deleted.

The Contract unit rate for transporting material from the excavation for structures shall be full compensation for all labour, equipment, tools, andincidentals necessary on account of the additional haul or transportation involved beyond the initial lead of 2000 m.

1101. DESCRIPTION

1101.1. This work shall consist of construction of all types of piles for structures in accordance with the details shown on the drawings and conforming to the requirements of these specifications.

1101.2. The construction of pile foundations requires a careful choice of the piling system depending upon subsoil conditions and loading characteristics and type of structure. The permissible limits of total and differential settlements, unsupported length of pile under scour, impact/entanglement of floating bodies and any other special requirements of project are also equally important criteria for selection of the piling system. The method of installing the piles, including details of the equipment shall be submitted by the Contractor and got approved from the Engineer.

1101.3. The work shall be done as per IS : 2911 except as modified herein.

1102. SUBSURFACE INVESTIGATION

1102.1. The complete subsurface investigation of strata in which pile foundations are proposed shall be carried out in advance and by insitu pile tests. For details of geotechnical subsurface explorations reference may be made to Section 2400. At least one borehole for every foundation of the bridge shall be executed. Borings should be carried upto sufficient depths so as to ascertain the nature of strata around the pile shaft and below the pile tip. However, depth of boring shall not be less than:

1) 1.5 times estimated length of pile in soil but not less than 15 m beyond the probable length of pile

2) 15 times diameter of pile in weak/jointed rock but minimum 15 m in such rock

3) 4 times diameter of pile in sound, hard rock but minimum 3 m in such rock

1102.2. The subsurface investigation shall define adequately stratification of sub-strata including the nature and type of strata, its variation and extent and specific properties of the same. The investigation shall be adequate for the purpose of selection of appropriate piling system and for estimating design capacities for different diameters and length of piles.

1102.3. Pressure meter tests may be used in the case of rock, gravel or soil for direct evaluation of strength and compressibility characteristics. Though these tests are of specialised nature they are most appropriate for difficult/uncertain substrata especially for important projects.

1102.4. For piles socketed into rocks, it is necessary to determine the uniaxial compressive strength of the rock and its quality.

The investigation shall also include location of ground water table and other parameters including results of chemical tests showing sulphate and chloride content and any other deleterious chemical content in soil and/or ground water, likely to affect durability.

1103. TYPE OF PILES

The piles may be of reinforced concrete, prestressed concrete, steel or timber. The piles may be of solid or hollow sections or steel cased piles filled with concrete. Co ncrete piles may be driven cast-in-situ or precast or bored cast-in-situ or precast piles driven into performed bores. The shape of piles may be circular, square, hexagonal, octagonal, H or I Section.

1104. MATERIALS

1104.1. The basic materials shall conform to the specifications for materials given in Section 1000. The specifications for steel reinforcement, structural concrete, prestressed concrete and structural steel to be used in pile foundations shall be as given in the relevant sections.

1104.2. Concrete in Piles

Grade of concrete to be used in cast-in-situ piles shall not be less than M 20 and the cement content shall not be less than 400 kg per cubic meter of concrete. Grades of concrete for precast reinforced and prestressed concrete piles shall not be less than M 25 and M 35 respectively. Maximum water cement ratio shall be 0.5 for cast-in-situ piles and 0.45 for precast piles.

The minimum slump of concrete for driven cast-in-situ piles shall be 100 mm to150 mm to 200 mm and that of bored cast-in-situ piles 150 mm to 200 mm. The slump should not exceed 200 mm in any case.

Concrete mix should have homogeneous mixture with required workability for the system of piling adopted. Suitable and approved admixtures may be used in concrete mix where necessary.

Where piles are exposed to action of harmful chemicals or severe conditions of exposure due to presence of sulphate, chloride etc. it may be preferable to opt for higher grades of concrete restricting water cement ratio to 0.45. Special types of cement, such as sulphate resistant cement may be used where considered appropriate.

1105. TEST PILES

1105.1. Test piles which are shown on the drawings or specified in the contract or installed by the Contractor on his own to determine the lengths of piles to be furnished shall conform to the requirements for piling as indicated in these specifications, if they are to be incorporated in the completed structure.

Test piles that are to become a part of the completed structure shall be installed with the same type of equipment that is proposed to be used for piling in the actual structure.

Test piles which are not to be incorporated in the completed structure shall be removed to at least 600 mm below the proposed soffit level of pile cap and the remaining hole shall be backfilled with earth or other suitable material.

The piles shall be load tested in accordance with provisions laid down in this section.

1106. PRECAST CONCRETE PILES

1106.1. General

Precast concrete piles shall be of the size and shape as shown in the approved drawings. If a square section is employed, the corners shall be chamfered at least 25 mm unless otherwise specified on the drawings. The length of pile shall not normally exceed25 metres. However, where special equipments for handling and installation are available to the satisfaction of the Engineer, longer length could be permitted.

Piles shall be cast with a driving point and for hard driving, shall be shod with a metal shoe approved by the Engineer.

1106.2 Stacking, Storing and HandlingD.6.1.25

D.6.1.27

D.6.1.26 Care shall be taken that all stages of transporting, lifting and handling, piles are not damaged or cracked. During transport and stacking of piles, they shall be supported at the same points as those provided for lifting purposes. If the piles are put down temporarily during handling, they shall be placed on trestles or blocks located at the same points.

D.6.1.28 Piles shall be stored at least 300 mm above firm level ground which is not liable to unequal subsidence or settlement under the weight of the stack of piles. They shall be placed on timber supports which are level and spaced so as to avoid bending. The supports shall be vertically one above the other. Spaces shall be left round the piles to enable them to be lifted without difficulty. The order of stacking shall be

such that the older piles can be withdrawn without disturbing newer piles. Separate stacks shall be provided for different lengths of piles. Where piles are stacked in layers, the number of layers shall not exceed three. Whenever curing is needed during storage, arrangements shall be made to enable the piles to be watered. For detailed precautions with regard to curing operations specifications for structural concrete given in Section 1700 shall apply.

Before the operation of handling and driving the piles, the minimum periods counted from the time of casting shall be allowed for as indicated in Table 1100-1. Prestressed piles shall not be lifted or handled until fully stressed.

TABLE 1100-1 TIME FOR CURING PRECAST PILESType of cementused in casting the pileMinimum periods from time of casting

Strike sideshutters(hours)End of wetcuring (days)Lift fromcasting bed(days)Drive (days)

Ordinary Portland

Rapid hardeningPortland24

127

710

728

10

1106.3. Lengthening of Piles

Where a pile is to have another length cast on it during driving, the longitudinal reinforcement shall preferably be joined by full penetration butt welding. The concrete at the top of the original pile shall be cut down to expose not less than 200 mm of the bars to avoid spalling of the concrete by heat. The added bars have to be held accurately and rigidly in position during welding. Where facilities on site are insufficient to make proper butt welding practicable, the joint may be made by lapping. The reinforcement at the head of pile will need to be exposed for full anchorage length or 600 mm whichever is greater and the new bars over-lapped for this distance. Unless otherwise specified, the extension of the pile shall be formed to the same crosssectional profile and with concrete of at least the same strength as that specified for the original pile. The stirrup spacing shall in no case be greater than 150 mm. Not more than one extension shall be permitted. In case more than one extension is permitted by the Engineer, only approved mechanical couples shall be used.

Driving shall not be resumed until:

(i) The strength of the concrete in the extension is at least equal to the specified characteristic strength of concrete in pile, and

Sabarmati River front development Corporation Page 30 of 117(ii) The approval of the Engineer has been obtained.

1106.4. Removal of Surplus Length

Any length of pile surplus to that required for incorporation in the structure shall be cut off neatly and removed. During the process of cutting off, it shall be ensured that projecting reinforcement to be anchored into the pile cap and the prestressing strands/wires are not damaged. When stripping prestressed concrete piles, shock release of tendons shall be avoided. Reference may also be made to clause 7.7.1. of IS :2911(Part I Section 3) in this connection.

1106.5. Risen Piles

Level reading should be taken on each pile after driving and again after all the piles are driven. Piles which are found to have risen due to ground heave or as a result of driving adjacent piles, shall be re-driven to the original depth or resistance unless re- driving tests on adjacent piles have shown this to be unnecessary.

1106.6. Manufacture

The pile should be cast in one continuous operation from end to end of each pile. Manufacture of precast concrete piles shall conform to the guidelines contained in clause Nos. 7.1, 7.2 and 7.3 of IS : 2911 (Part I, Section 3).

Pile shall be provided with suitable shoe for protecting the point of the pile during driving in hard ground.

Piles shall not be moved from casting bed until the concrete has hardened sufficiently.

Piles shall not be driven in less than 28 days after casting or unless their strength at the time of driving is at least that specified for 28 days.

1106.7. Prestressed Concrete Piles

D.6.1.29 Additional specifications for precast prestressed concrete piles shall conform to those contained in clause 8 of IS : 2911 (Part I Section 3).

1107. CAST-IN-SITU CONCRETE PILES

Cast-in-situ concrete piles may be either installed by making a bore into the ground by removal of material or by driving a metal casing with a shoe at the tip and

displacing the material laterally. The two types of piles are termed as bored piles and driven piles respectively. Cast-in-situ concrete piles may be cast in metal shells which may remain permanently in place. However, other types of cast-in-situ concrete piles, plain or reinforced, cased or uncased, may be used if in the opinion of the Engineer the soil conditions permit their use and if their design and the methods of placing are satisfactory.

The metal casing shall be of sufficient thickness and strength to hold its original form and show no harmful distortion after it and adjacent casings have been driven and the driving core, if any, has been withdrawn.

Cast-in-situ concrete driven piles shall be installed using a properly designed detachable shoe at the bottom of the casing. Certain specific requirements of cast-in-situ driven piles shall be as per Clauses 1110 and 1111.

Any liner or bore-hole which is improperly located or shows partial collapse that would affect the load carrying capacity of the pile, shall be rejected or repaired as directed by the Engineer at the cost of the Contractor.

Wherever practicable, concrete should be placed in a clean dry hole. Where concrete is placed in dry and there is casing present, the top 3 m of the pile shall be compacted using internal vibrators. The concrete should invariably be poured through a tremie with a funnel so that the flow is directed and concrete can be deposited in the hole without segregation.

Where the casing is withdrawn from cohesive soils for the formation of cast-in- situ pile, the concreting should be done with necessary precautions to minimise the softening of the soil by excess water. Where mud flow conditions exist, the casing of cast-in-situ piles shall not be allowed to be withdrawn.

Care shall be taken during concreting to prevent as far as possible the segregation of the ingredients. The displacement or distortion of reinforcement during concreting and also while extracting the tube shall be avoided.

If the concrete is placed inside precast concrete tubes or consists of precast sections, these shall be free from cracks or other damage before being installed.

The concrete shall be properly graded, shall be self-compacting and shall not get mixed with soil, excess water, or other extraneous matter. Special care shall be taken in silty clays and other soils with the tendency to squeeze into the newly deposited concrete and cause necking. Sufficient head of green concrete shall be maintained to prevent inflow of soil or water into the concrete.

The placing of concrete shall be a continuous process from the toe level to the top of the pile. To prevent segregation, a tube or tremie pipe as appropriate shall be used to place concrete in all piles.

To ensure compaction by hydraulic static heads, rate of placing concrete in the pile shaft shall not be less than 6 m (length of pile) per hour.

Bored cast-in-situ piles in soils which are stable, may often be installed with only a small casing length at the top. A minimum of 2.0 m length of top of bore shall invariably be provided with casing to ensure against loose soil falling into the bore. In cases in which the side soil can fall into the hole, it is necessary to stabilise the side of the bore hole with drilling mud, or a suitable steel casing. The casing may be left in position permanently specially in cases where the aggressive action of the ground water is to be avoided, or in the cases of piles built in water or in cases where significant length of piles could be exposed due to scour.

For bored cast-in-situ piles, casting/liner shall be driven open ended with a pile driving hammer capable of achieving penetration of the liner to the length shown on the drawing or as approved by the Engineer. Materials inside the casing shall removed progressively by air lift, grab or percussion equipment or other approved means.

Where bored cast-in-situ piles are used in soils liable to flow, the bottom of the casting shall be kept enough in advance of the boring tool to prevent the entry of soil into the casing, thus preventing the formation of cavities and settlements in the adjoining ground. The water level in the casing should generally be maintained at the natural ground water level for the same reasons. The joint of the casing shall be made as tight as possible to minimise inflow of water or leakage of slurry during concreting.

Boring shall be carried out using rotary or percussion type equipment. Unless otherwise approved by the Engineer, the diameter of the bore-holes shall be not more than the inside diameter of the liner.

Prior to the lowering of the reinforcement cage into the pile shaft, the shaft shall be cleaned of all loose materials. Cover to reinforcing steel shall be maintained by suitable spacers.

The diameter of the finished pile shall not be less than that specified and a continuous record shall be kept by the Engineer as to the volume of concrete placed in relation to the length cast.

Before concreting under water, the bottom of the hole shall be cleaned of drilling mud and all soft or loose material very carefully. In case a hole is bored with use of drilling mud, concreting should not be taken up when the specific gravity of bottom slurry is more than 1.2. The drilling mud should be maintained at 1.5 m above the ground water level.

Concreting under water for cast-in-situ concrete piles may be done either with the use of tremie method or by the use of an approved method specially designed to permit under water placement of concrete.

General requirements and precautions for concrete under water are as follows:

(a) The concreting of a pile must be completed in one continuous operation.Also, for bored holes, the finishing of the bore, cleaning of the bore, lowering of reinforcement cage and concreting of pile for full height must be accomplished in one continuous operation without any stoppage.

(b) The concrete should be coherent, rich in cement with high slump and restricted water cement ratio.

(c) The tremie pipe will have to be large enough with due regard to the size of aggregate. For 20 mm aggregate the tremie pipe should be of diameter not less than 150 mm and for large aggregate, larger diameter tremie pipes may be necessary.

(d) The first charge of concrete should be placed with a sliding plug pushed down the tube ahead of it to prevent mixing of water and concrete.

(e) The tremie pipe should always penetrate well into the concrete with an adequate margin of safety against accidental withdrawal if the pipe is surged to discharge the concrete.

(f) The pipe should be concreted wholly by tremie and the method of deposition should not be changed part way up the pile to prevent the laitance from being entrapped within the pipe.

(g) All tremie tubes should be scrupulously cleared after use.

The minimum embedment of cast-in-situ concrete piles into pile cap shall be 150 mm. Any defective concrete at the head of the completed pile shall be cut away and made good with new concrete. The clear cover between the bottom reinforcement in pile cap from the top of the pile shall be not less than 25 mm. The reinforcement in the pile shall be exposed for full anchorage length to permit it to be adequately bonded into the pile cap. Exposing such length shall be done carefully to avoid damaging the rest of the pile. In cases where the pipe cap is to be laid on ground, a leveling course of M 15 nominal mix concrete 100 mm thick shall be provided. Defective piles shall be removed or left in place as judged convenient without affecting the performance of adjacent piles or pile cap. Additional piles shall be provided to replace the defective piles.

1108. STEEL PILES

Steel piles shall be H or I sections as shown on the drawings and shall be of structural steel conforming to the specifications given in Section 1000.

Steel piles shall be protected by suitable anti-corrosive painting as specified on the drawing. Piles shall be stored above the ground using protective packing to minimise damage to surface coating. Each pile shall be supplied preferably in one piece without splices.

At the option of the Contractor, steel piling consisting of structural steel plates welded together may be substituted for the rolled sections specified, provided that the depth, width and average thicknesses are at least equal to those of the rolled sections, the steel plates conform to specification given in Section 1000, the flanges are welded to the web with continuous fillet welds on either side of the web, and the welding conforms to Clause 1904.8 of these specifications.

The length of the steel pile may be built up in sections either before or during driving operations. The sections shall be of identical cross-section. Pile splices shall be made with full penetration butt welds over the whole cross-section. Pile splices shall develop at least the yield strength of pile.

The connections shall be made by butt-welding the entire cross-section in accordance with the provisions in Clause 1904.8 of these specifications. Care shall be taken to properly align the sections connected so that the axis of the pile will be straight. The number of welded connections in the length of pile shall be as few as possible.

1109. Timber Piles

The Engineer shall stamp each pile on the butt with a stamp which shall make an impression that is readily legible. Treated timber piles will be inspected by the Engineer after treatment.

Untreated timber may be used as test piles.

Untreated timber piles and treated timber piles shall be of approved quality. Treated timber piles shall be driven within 6 months after treatment.Timber piles shall be furnished with tip protection and shall be protected by the use of steel straps as hereinafter specified. Tip protection shall be suitable for use on timber piling of the size to be driven. Details of tip protection shall be furnished to the Engineer for review and approval before driving piles. Not less than 2 separate steel straps shall be placed within 600 mm of the butt of each pile after the pile is square cut. Not less than 2 separate steel straps shall be placed within 300 mm of the tip of each pile.

Additional intermediate steel straps shall be placed at not more than 3 metres centre measured along the length of the pile.

Timber piles which are to be capped shall be separately cut off so that true bearing is obtained on every pile. Piles inaccurately cut off shall be replaced. Splicing of timber piles shall not be permitted except by written permission of the Engineer.

1110.Driving Equipment

Piles or their casings may be driven with any type of drop hammer, diesel hammer or single-acting steam or compressed air hammer, provided they penetrate to the prescribed depth or attain the designed resistance without being damaged. The weight or power of the hammer should be sufficient to ensure a penetration of at least 5 mm per blow, unless rock has been reached. It is always preferable to employ the heaviest hammer practicable and to limit the stroke, so as not to damage the pile. The minimum weight of the hammer shall be 2.5t. In the case of precast concrete piles the mass of the hammer shall be not less than 30 times the mass of 300 mm length of pile.

Stream or air hammers shall be furnished along with boiler or air compressor of capacity at least equal to that specified by the manufacturer of the hammers. The boiler or air compressor shall be equipped with an accurate pressure gauge at all times. The valve mechanism and other parts of steam, air or diesel hammers shall be maintained in first class condition so that the length of stroke and number of blows per minute for which the hammer is designed, will be obtained. Inefficient steam, air or diesel hammers shall be removed from the work.

1111. DRIVING

1111.1. General Procedure

Details of the equipment and the method proposed for driving the piles shall be submitted with the tender for scrutiny and approval of the Engineer. Piles shall be installed from firm ground or from temporary supports or from fixed platform. The arrangement shall provide sufficient rigidity to ensure accuracy of pile driving under all conditions of tide, stream flow or hammer drop.

During driving the top of pile shall be protected by a suitable helmet of substantial steel construction. The helmet shall provide uniform bearing across the top of the pile and shall hold the pile centrally under the hammer. No pile shall be driven unless inspected and approved by the Engineer.

Piles shall be driven from a fixed frame of sufficient rigidity to ensure accuracy of driving within specified tolerances. Forces producing undue bending or torsional stresses in piles shall not be applied during driving. The force of the hammer shall be directed centrally and axially during driving.

The stroke of a single acting or drop hammer shall be limited to 1.2 m unless otherwise permitted by the Engineer. A shorter stroke may be necessary when is danger of damaging the pile.

Piles shall not be bent or sprung into position but shall be effectively guided and held on-line during the initial stages of driving. Attempts to correct any tendency for the pile to run off-line by the application of significant horizontal restraint will not be permitted. Shortly after the commencement of driving and at regular intervals throughout the driving operation, checks shall be made to ensure that the pile frame does not exert any undue lateral force on the pile due to restraint within the helmet.

If the indications are that a pile will finish outside the specified tolerances, driving operations on that pile will cease. The pile shall be withdrawn, the hole filled and the pile re-driven at no extra cost.

To avoid the possibility of premature set-up pile driving shall be continuous in the later stages, without any deliberate stops. (Delays of an hour or less may lead to significant set-up in piles i.e. resistance to further driving increases after driving is stopped).

If any pile is damaged in any way during driving, it shall be repaired or replaced as directed by the Engineer, at no extra cost. If during driving, the head of a pile is damaged to the extent that further driving is not possible, the head shall be cut off and driving continued. The cost of cutting off shall be borne by the Contractor and where, as a result of such cutting off the head, the pile is too short, the Contractor, shall, at his own cost, supply and splice on sufficient length of pile to restore the pile to its correct length.

Piles should be driven to the minimum acceptable penetration shown on the drawings. This may require preboring and/or jetting as indicated in these specifications with the full approval of the Engineer.

Piles shall be driven to nominal refusal or the required ultimate dynamic capacity nominated on the drawings or until the top of the pile is at the level required and specified on the drawing whichever gives the lowest toe elevation. The Engineers decision in these matters shall be final. Nominal refusal shall be taken as equivalent to 25 mm total penetration for the final 20 blows using a hammer of driving energy as specified and shall be used as the criterion for acceptance for piles founded on rock. Severe driving which results in an average set per blow less than 0.5 mm will not be permitted.

Where hard drilling is encountered because of dense strata or obstructions located above the predetermined pile tip level, nominal refusal shall not be considered to have been achieved unless the Engineer is satisfied that the total number of blows, as the average driving resistance specified for nominal refusal, indicates that further driving will not advance the pile through dense strata or obstructions.

The pile shall be driven as accurately as possible to the vertical or to specified batter. Straining the pile into position can damage it and the driving equipment should be adjusted as much as possible to follow the position of the pile. Any deviation from the proper alignment shall be noted and promptly reported to the Engineer. If the deviation is to such an extent that the resulting eccentricity cannot be taken care of by strengthening the pile cap or pile ties, such a pile shall, at the discretion of the Engineer, be repla ced or supplemented by an additional pile. Unless otherwise specified, the permissible positional deviation for piles shall be limited to those indicated in Clause 1116.

Care shall be taken not to damage the pile by over-driving. Any sudden change in the rate of penetration which cannot be ascribed to the nature of the ground shall be noted and its cause ascertained, if possible, before driving is continued.

When employing a tube which is subsequently withdrawn for the formation of cast-in-situ pile, consideration shall be given to the possibility of doing harm to a pile recently formed by driving the tube nearby before the concrete has sufficiently set. The danger of doing harm is greater in compact soils than loose soils. No pile shall be bored or driven within 3 m of a newly cast pile until at least 24 hours after completion of its installation.

Driving piles in loose sand tends to compact the sand which in turn increases the skin friction. Therefore, driving a number of friction piles in a group shall proceed outward from the centre as otherwise it will be difficult to drive the inner piles to the same depth as the others.

In case of stiff clay also, the driving for a group of piles shall proceed outward from the centre. However, in case of very soft soil, the driving may proceed from outside to inside, so that the soil is restrained from flowing out during driving operations.

If there is a major variation between the depth at which adjacent foundation piles in a group meet refusal, a boring shall be made nearby to ascertain the cause of this difference. If the boring shows that the soil contains pockets of highly compressive material below the level of the shorter pile, it will be necessary to enforce penetration of all the piles to a level below the bottom of the zone which shows such pockets.

1111.2. Preboring and Jetting

Driving of the piles may be assisted by preboring holes or by the use of jets or both subject to the approval of the Engineer. These may be used essentially to achieve the minimum penetration shown on the drawings where such penetration is not reached under normal conditions of driving indicated in Clause 1111.1.

The diameter of the hole shall not be greater than the diagonal dimension of the pile less 100 mm.

The maximum depth of the preboring shall be such that the specified set (or less) is obtained when the toe of the pile is at founding level. Preboring shall be as approved by the Engineer and shall not extent below one metre above the founding level and the pile shall be driven to at least one metre below the prebored hole. To ensure that the pile is properly supported laterally in the hole, any space remaining around the pile at the ground level after driving is finished shall be backfilled with approved granular material.

When water jetting is used, at least two jets shall be attached to the pile symmetrically when this type of technique is used. The volume and pressure of water at the outlet nozzles shall be sufficient to freely erode material adjacent to the toe of the pile. The maximum depth of jetting shall be such that the specified set (or less) is obtained when the toe of the pile is at founding level. Jetting shall cease as directed by the Engineer and shall not proceed below one metre above the founding level and the pile shall be driven at least one metre below the pre-bored hole.

To avoid very hard driving and vibration in materials such as sand, jetting of piles by means of water may be carried out only by express permission of the Engineer and in such a manner as not to impair the bearing capacity of the piles already in place, the stability of the soil or the safety of any adjoining buildings. Details of the arrangement for jetting shall be got approved from the Engineer in advance.

If, for jetting, large quantities of water are used, it may be necessary to make provision for collection of water when it comes to the ground surface, so that the stability of the piling plant is not endangered by the softening of the ground.

Jetting shall be stopped before completing the driving which shall always be finished by ordinary methods. Jetting shall be stopped if there is any tendency for the pile tips to be drawn towards the pile already driven owing to the disturbance to the ground.

1112. RAKER (INCLINED) PILES

The maximum rake to be permitted in piles shall not exceed the following:

i) 1 in 8 for larger diameter cast-in-situ piles viz 0.75 m diameter and above ii) 1 in 5 for smaller diameter cast-in-situ pilesiii) 1 in 4 for precast driven piles

1113. PILE TESTS

1113.1. General

The bearing capacity of a single pile may be deter