Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
NBCC (INDIA) LIMITED
(A Government of India Enterprise)
(Formerly known as National Buildings Construction Corporation Limited)
TECHNICAL SPECIFICATION
PART – I - PROVIDING & LAYING BORED CAST IN SITU RCC PILES FOR BOUNDARY WALL
1.1 GENERAL
The work is to be executed as per latest CPWD Technical specifications-2019 and amendment, if any.
Piles find application for foundations in low bearing capacity soils to transfer loads from a structure to
competent subsurface strata having adequate load bearing capacity. Piles transfer axial loads through
friction along its shaft and/ or by the end bearing. The installation of piles demands careful control on
position, alignment and depth and involve specialized skill and experience of working in soils of different
characteristics. These specifications cover scope of work, the material specification installation, load test
on piles, mode of measurement.
1.2 SCOPE OF WORK
The scope of work covers the checking Geo-technical design of pile provided by the Owner and
construction of reinforced concrete load bearing piles, the load tests on the pile, installation and testing
of test piles and guarantee of pile capacities, mix design including all materials and kentledge for
testing. It also covers the preparation and submission of As-built drawings indicating the actual location
of piles and the pile records for each pile.
SURVEY WORK:
Vegetation, debris available on site shall be removed and general site grading of plot shall be done to
start the layout work.
The layout work of site structure to be done as per the site layout plan.
Based on the site layout plan and centerline plan of the structure, pile point locations shall be
marked on the ground.
These pile point marks shall be concreted, painted and kept protected with sand filled gunny
bags.
PILE BORING WORK
Positioning of piling hydraulic rig on pile location.
Placing center of drilling auger on the pile location and check the centre.
Fixing additional side reference pegs/rods to check horizontal location of the pile before boring
gets started. Also using these reference pegs, place the permanent liners in required location and
position.
Bailing out over burden soil using auger up to required depth in loose strata below G.L.. Top
surface of the ground where piling is to be done, may have concrete surface , hence vendor to consider
the same while quoting.
Positioning permanent bottom liner of required length and drive the same inside the pre- bored
hole using a Vibro hammer.
At the time of driving the permanent liner, the verticality of the liner to be checked with visual
inspection and checking the distance between the reference pegs and the outside face of the liner.
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
Bailing out additional soil from the bottom of the hole with auger and bucket and subsequently if
required add another small piece of required length liner further into soil strata using a Vibro hammer.
Care shall be taken that the permanent liner shall be drive up to the non-collapsible strata.
The permanent liner shall be provided from the existing ground level to prevent collapse of the
bore while carrying out the various balance activities and up to the depth of non-collapsible strata.
The extra liner and concrete above the cut off level of the pile shall be cut at the time of the pile
cap work, after completion of P.C.C. work.
Identification of bed rock shall be done as per the rate of penetration of auger in to the strata
and shall also be compared with soil investigation report.
The rock cutting action of auger shall be observed and rock samples shall be collected.
3 Rock cutting shall be carried out as recommended in soil investigation report. The socketing
of the pile in the rock shall be done as per the requirement and the specifications.
After the strata reaches the termination criteria for pile as per the specifications and by visual
examination of rock samples & the soil investigation Report i.e. bore logs, the pile shall be terminated.
The final depth of clear borehole shall be taken and recorded jointly. The final depth after
socketing in the rock shall be got approved from the client/consultant.
REINFORCEMENT
To fabricate pile reinforcement cages as per the detail drawings and provide the cover block at
an interval of 2 meters and shall be made of M30 grade concrete.
Lowering the required length of reinforcement cage in the borehole with the help of crane or
Hydraulic rig.
The extension of the cage to be carried with overlapping two cages and the lap length shall be
as per specifications requirements.
The New additional cage to be overlapped to the previous cage which is kept supported in
hanging position in the bore hole and as the depth of the pile can not be fixed the lapping of cages at
site shall be at one location only and hence can not be staggered. However the laps to be stitch welded
to prevent slippage/distortion.
IV CONCRETING
As in this case, permanent liners are being used which starts at ground level and ends at the
non collapsible strata, there are no chances of any muck or soil collapse in the bore hole. Using the
Hydraulic rig, the cleaning of the bore hole bottom in the rock shall be done using the Hydraulic Bucket.
After the cage lowering finishes, Lower 200 mm dia. tremie pipe in the bore up to the required
depth.
Fixing the tremie hopper at the top, place plug.
Pouring the high slump concrete as per design mix. with the slump between 150 mm 180 mm.
Filling the concrete in hopper fully.
Removing plug and charge concrete though tremie.
After placing concrete though tremie, leakage of water entry or water surge through tremie pipe
to be checked before commencing 2 nd filing of concrete and throughout the concrete placement.
Again filling the hopper fully and charge the concrete inside the hole. Overlap of about 1.00
meter in concrete mass in the hole and tremie pipe to be maintained so that extra head of concrete
shall be maintained to avoid water entry in tremie pipes. 5
While pouring concrete through tremie, hopper to be jerked up and down to spread the
concrete in the pile body this operation also compacts the concrete.
Tremie to be withdrawn slowly maintaining sufficient overlap of concrete in hole and in tremie.
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
The pouring of concrete shall continued till lean concrete mixed with slurry shall come out from
the bore hole above the cut off level of the pile, To achieves this each pile shall be concreted above
their cut off level as specified and also these overflow concrete shall be approved by Engineer I/C.
Removing remaining tremie pipes, bottom and hopper from the casing/hole.
Each & every stage of boring, reinforcement, concreting etc. shall be recorded.
In case of this job, reinforcement cage may required to be fabricated at other place and to be
transported separately to the site. No extra cost shall be paid on a/c of same.
1.3 APPLICABLE CODES & SPECIFICATIONS.
a) Unless otherwise specified the design materials and workmanship shall conform to the following
standards.
IS: 456 Code of Practice for Plain & Reinforced Concrete.
IS: 269: Ordinary Portland Cement
IS: 6909: Specs. For Super Sulphated Cement
IS: 383: Test of materials IS: 1200: Mode of Measurements for Civil Works
IS:432: Mild Steel & Medium Tensile Steel bars and wires for concrete reinforcement.
IS: 1139: Specs. For Mild Steel and medium tensile steel bars and high yield strength steel deformed
bars for concrete reinforcement.
IS: 1786: Cold twisted Steel Bars IS:1566: Hard drawn steel wire fabric for concrete Reinforcement.
IS:2502 : Bending and fixing bars. IS:2911 : (Part I to IV) - Design & Construction of Piled
Foundations. I.S:12330: Sulphate Resisting Portland Cement
IS:8112: Specification for 43 grade cement
IS:2062: Specs for Structural Steel (Standard Quality)
IS:12269: Specs for 53 grade cement IS:2720: Methods of Test for Soil
IS:1489 Specs. For Pozzolona Portland Cement
b) The specification, standards and codes referred herein are made part of this specification and shall
apply to work except as may otherwise be stated. 3
c) For such items of work which may arise and which is not covered by the specifications or by relevant
Indian Standard Specification, the decision of the Owner/ Engineer regarding specifications of such work
shall be final and binding to the Contractor.
1.4 MATERIAL
a) . CEMENT :The cement shall be conforming to IS-12330 /IS-269/ IS 12269 /IS-1489 /1S-6909.
b). REINF STEEL: Major reinforcement shall be conforming to IS:1786 Stirrups/spiral shall conform to
IS:432.
c). AGGREGATE : All aggregates shall conform to I8:383 and IS:515, coarse aggregate shall be crushed
from blue basalt /hard granite and shall be hard and free from weathering. The material shall be graded
to achieve homogeneous mix.
d). FINE AGGREGATE : This shall be free from dust and silty sand and from original impurities. Sand
shall be washed by the contractor at no extra cost to the client, if it contains silt more than 4%. River
sand approved by Engineer/Owner must be used for RCC works. The grading of fine aggregates shall be
determined as per IS:2386 (Part I) and shall be within the limits given in Table 4 of IS:383. Sand shall
also have to be washed off if it contains silt more than allowable limits.
e). WATER : Water to be used shall be free from injurious and deleterious materials. Water safe for
drinking shall be used. Clean water, free from acids and other impurities shall be used in the
manufacture of concrete. Water shall be conforming to IS:456 Clause 5.4 & Table-1.
f). CONCRETE:
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
a. Materials and methods of manufacture of cement concrete shall in general be in accordance with the
method of concreting under the conditions of pile installation.
b. The slump for concrete shall be as follows: Min Max.
i) Driven cast in situ piles 100 180
ii) Cast-in-situ bored piles:
a) Water free unlined bore with wide space reinforcement. 100 150
b) Tremie concreting 180 180
iii) Under reamed piles:
a) Water free unlined bore holes 100 150
b) Tremie concreting 150 200
c. Consistency of concrete to be used for the piles shall be suitable to the method of installation of piles.
Concrete shall be so designed or chosen as to have a homogeneous mix having a slump / workability
consistent with the method of concreting under the given conditions of pile installation.
d. The grade of concrete to be used for piling shall be Min NBCC or as indicated in the BOQ, with the
minimum cement content of 400 kg/Cu.M. Mixing shall be carried out in mechanical mixer only. In case
of piles subsequently exposed to free water or in case of piles where concreting is done under water or
drilling mud using method Other than trimie, 10% extra cement over the design grade of concrete at
the specified slump shall be used subject to a minimum quantity of cement specified above. The
contractor shall carry out the mix design for the above grade of concrete and submit the report prior to
concreting at no extra cost to the Owner. For the design purpose of bore cast-in-situ piles, the strength
of concrete mix using above mentioned quantities of 5 cement shall be taken as M30.
e. Concreting for the piles shaft be done with tremie of suitable diameter.
f. Natural rounded shingle of appropriate size may be used as coarse aggregate. It helps to give high
slump with less water cement ratio. For tremie concreting aggregates having nominal size more than
20mm shall not be used.
1.5 The Contractor shall check the design providedand indicate the load carrying capacities of piles in
direct compression, lateral thrust and uplift which is achievable by him, along with supporting
calculations based on Soil Investigation Report supplied to him. The Contractor to note that the design
calculations included in the Geotechnical investigation report (if any), are indicative only. The
calculations of set shall also be submitted in case of precast piles. The Contractor will give a written
confirmation in case the same is agreeable to him. In case the contractor feels necessary to have
additional exploratory investigation, the same shall be done by the contractor. The cost towards this
investigation shall be included by the Contractor in his piling cost.
1.6 Guarantee
The Contractor shall stand guarantee for vertical, horizontal and uplift capabilities of proposed piles
under all operating, erection and driving conditions for loads imposed by permanent structure resting
on piles and will be responsible for all damages due to the failure of pile foundation and hence the
structure. The guarantee will be operative for a period of 1 (one) year from the date of completion of
piling.
1.7 The tenderer / Contractor shall furnish the Quality Assurance plan along with the tender furnishing
the name of the Engineer who will be responsible for the quality.
1.8 For each pile, record of the following data shall be kept: A. Type of Pile B. Identification mark with
Drg.No. and Rev. C. Dia. of Piles D. Ground level E. Cut-off level of pile F. Founding Level G. Length of
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
Pile H. Grade of Concrete I. WIC Ratio J. Reinforcement Details with Drg.No. and Rev. K. Piling - i)
Starting Time ii) Finishing Time L. Concrete i) Starting Time ii) Finishing Time
1.9 LOAD TEST ON PILES
These would be conducted on piles on completion of 28 days after casting. Two types of tests namely
initial and routine tests, for each type of loading viz. Vertical, horizontal( lateral), pull out are performed
on piles. 7
1.9.1 This test shall be performed to confirm the design load calculations and to provide guidelines for
setting up the limits of acceptance for routine tests. It also gives an idea of the suitability of the piling
system. Initial Test on piles are to be carried out at one or more locations depending on the no. of piles
required. Load applied for the initial (cyclic) load test shall be 2.5 times the safe carrying capacity of the
pile. Loading for Initial Tests shall be conducted as per Appendix 'A' Clause 6.3 of IS-2911 Part IV.
1.9.2 Routine Tests Selection of piles for the Routine Test shall be done by the Engineer subject to a
maximum of % of total no. piles required. The no. of tests may be increased to 2% depending on the
nature / type of structure. The test load applied shall be 1 1/2 times the safe carrying capacity of the
pile. This test will be performed for the following purposes: a) To ensure the safe load capacity of piles
b) Detection of any unusual performance contrary to the findings of the Initial Test.
1.9.3 THE TESTS SHALL BE PERFORMED AT THE CUT-OFF LEVEL ONLY
1.9.4 The Contractor shall submit a detailed report for the test result in duplicate to client / consultant
1.9.5 Vertical Load Tests This test will be carded out as stipulated in IS-2911 (Part IV) 1995. Pile Head
-The pile head shall be chipped off till sound concrete is met wherever applicable. The reinforcement
shall be cut and head levelled with Plaster of Pads. A bearing plate with a hole shall be placed on the
head for the jack to rest. 8 Reaction - Kentleclge shall be suitably designed to get the desired reaction
on the piles. Anchor piles (if required) shall be placed at a centre to centre distance of 3 times the pile
diameter subject to a minimum distance of 2 M. Settlement -2 dial gauges for a single pile and 4 dial
gauges for a group of piles with 0.01 mm sensitivity shall be used. They shall be positioned at equal
distance around the piles on datum bars resting on immovable supports at a distance of 3D (min. of 1.5
m) where 0 is the diameter of pile or circumscribing circle for non-circular piles. Application of load- It
shall be applied as specified depending on the type of test (routine/initial). Each load shall be
maintained till the rate of displacement of the pile top is either 0.1 mm in the first 30 minutes or 0.2
mm in the first one hour or 2 hours whichever occurs first. The next increment in the load shall be
applied on achieving the aforesaid criterion. The test load shall be maintained for 24 hours. Initial Tests
- The safe load on a single pile shall be the least of the following: (i) 2/3 rd 1 of the final load at which
the total displacement attains a value of 12 mm unless otherwise required in a given case on the basis
of nature and type of structure in which case, the safe load should be corresponding to the stated total
displacement permissible. (ii) 50% of the final load at which the total displacement equals_ 10% of the
pile diameter in case of uniform diameter piles or 7.5% of the bulb diameter in case of under reamed
piles. Routine Tests - Acceptance The maximum settlement at test load should not exceed 12 mm.
1.9.6 Lateral Load Tests: The jack should be placed horizontally, between two piles. The load on the
jack shall be the same on both the piles. The load will be applied in increments of 20% of the estimated
safe load and at the cut off level. The load will be increased after the rate of displacement is nearer to
0.1 mm per 30 minutes. If the cut-off level is approachable, one dial gauge exactly at the cut-off level
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
shall measure the displacement. In case the cut-off level is not approachable, 2 dial gauges 30 cms.
apart vertically, shall be set up and the lateral displacement of the cut-off level calculated by similar
triangles. The safe load on the pile shall be the least of the following: a) 50% of the final load at which
the total displacement increases to 12 mm. b) Final load at which the total displacement corresponds to
5 mm.
1.9.7 Pull out tests A suitable set up shall be designed to provide an uplift force to the piles. The load
increments and the consequent displacements shall be as per the case of a vertical load test. The safe
load shall be the least of the following: a) 2/3rd of the load at which the total displacement is 12 mm or
the load corresponding to a specified permissible lift. b) Half of the load at which the load displacement
curve shows a clear break.
2.0 PILE HEAD
2.1 All the pile shall be concreted to a level at least 0.6 M above the cut off level. The extra height of
pile to be cast shall be minimum as per IS stipulations and also so determined by contractor in such a
way that after stripping to the cut off level, the concrete at the cut off level shall be dense and sound.
This shall be taken into account and included in Contractor's rates for piles. A few piles will 10 be
exposed up to 4 to 5M depth by the contractor at his own cost for inspection of pile shaft. If the pile
shaft shows defect, the Contractor shall rectify his equipments and methods.
2.2 In the circumstance where cut-off level is below ground water, the need to maintain a pressure on
the unset concrete equal to or greater than water pressure should be observed and accordingly length
of extra concrete above cut-off level shall be determined. In such case, if required the contractor may
have to cast the pile above cutoff level up to overflowing the concrete, above ground.
3.0 CONTROL OF ALIGNMENT
Piles shall be installed as accurately as possible according to the drawings. Greater care shall be
exercised in respect of installation of single pile or piles in two pile groups. For vertical pile a deviation
of 1.5% of plumb shall not be exceeded. Piles shall not deviate more than 75mm or 0/4 whichever is
less (75 m or 0/10 whichever is more in case of piles having diameter more than 600 mm) from their
designed positions at the working level of piling rig. In the case of single pile under column, the position
deviation shall not exceed 50 mm or 0/4 whichever is less (100 mm in case of piles having diameter
more than 600 mm). Piles not conforming to this requirement may at the discretion of the Engineer be
totally rejected and extracted if necessary at the contractor's cost. All consequences of such rejection
such as providing extra beams or any other measure whatsoever shall be at the Contractor's expenses.
4.0 DRIVEN CAST- IN - SITU - PILES
4.1 The safe capacities of different diameter of driven cast-in--situ-piles considered in arriving at the
quantities are as indicated in the Geotechnical investigation report.
4.2 The contractor may indicate his alternative geotechnical design with specification and achievable
pile capacities along with the supporting geotechnical design calculations. However the alternative shall
be only for driven 11 cast-in--situ-piles.
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
4.3 The above pile design calculations may be reviewed by the consultant and approved for the load
test and execution.
4.4 CONSTRUCTION The pile shall be formed within the ground by driving the temporary casing of
uniform diameter and adequate thickness and subsequently filling in the hole so formed with reinforced
concrete. The casing shall be installed with slug or a shoe at the bottom and to displace the subsoil. The
concrete shall be properly rammed to get maximum density. Construction procedure of piles shall be as
per IS:2911 (PART - 1 / SEC.1). Contractor's equipment and procedure shall be inspected and approved
by consultant before starting the job.
4.5 Set Criteria Contractor may submit his calculations for set criteria for the driven pile capacities and
diameters based on his equipment details in accordance with Appendix B (Clause 5.3.12) of 18:2011
(Part 1/SEC.1) The piles not conforming to the acceptance criteria shall be totally rejected at the
discretion of the Engineer/Owner and removed if required, at Contractor's cost. All consequences and
expenses of such rejection as providing additional piles, enlarging pile caps, providing extra beams or
any other measure whatsoever shall be borne by the Contractor.
5.0 BORED CAST-1N-SITU PILES
5.1 For this piling work, use of the following piling system is contemplated:- Casing / Liner pipe shall
be used for the loose / soft soil strata. As boring in soft material is liable for cavitation, boring tools
should not be operated below the toe of the casing. The casing shall be driven down through the soft
layer to penetrate a hard strata not subjected to cavitation and shall be sealed in this material as far as
possible. Thereafter, the boring shall continue by means of boring tools until the approved bearing
strata is reached.
5.2 Construction technique and construction of pile foundation shall be as per IS:2911 (Part I). Section
ill and they should further conform to the following particular requirements :
5.3 For bored piles : Not leaner than M-25 mix or as specified in BOQ.
5.4 The lengths of bars to be left over the cut-off level of the pile shall be as shown in drawings.
5.5 The bored piles should penetrate into the hard acceptable strata by a minimum of 550 mm or equal
to pile dia. whichever is greater, unless otherwise noted. 5.6 The density of the freshly prepared
bentonite solution should be between 1.03 and 1.10 gm/cm 3 . However, in this case, bentonite is not
to e used as liner pipes have been considered.
5.7 The Contractor shall note that the pile shall be installed in such sequence that the carrying capacity
of the previously installed pile is not reduced. The sequence for piling shall be as per working drgs.
and/or instructions of the Engineer.
5.8 Immediately before concreting, the bore hole shall be cleaned of all loose materials debris and all
the water shall be removed by pumping and bailing. Great care shall be taken to ensure that fluid
alluvial soil does not fall between batches of concrete. For marine situation, piles may be formed with
permanent cases (liner). In case, liner is used and the bore is filled with water or drilled fluid the
bottom part may be concreted using tremie method so that the liner is effectively sealed against ingress
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Construction of Boundary Wall for extended campus of IIT Delhi at Village Badsa, Distt Jhajjar, Haryana
Technical Specifications
of ground water and then the upper part can be concreted in dry after proper inspection of the top
surface of the concrete in so Placed under water.
5.9 Jetting may have to be used to penetrate the pile through top stiff clay. The cost of such jetting is
assumed to be included in basic pile cost and no additional payment will be made on this account.
6.1 Test Pile: The test pile shall be bored and cast as per design at the location. However, if the test
pile fails, Contractor has to fabricate new test pile of suitable length and drive immediately. Contractor
to note that working pile shall not be driven until test piles satisfy load test requirement. However
Contractor can keep his material, labour and equipments ready to fabricate the working piles in shortest
time.
6.2 Clearance of site subsequent to pilling operations Contractor must include in his rate clearing of
muck arising out of pilling operations and depositing the same anywhere within site and dressing the
same of imposing it off with a lead up to 1.0 to 2.0 Kms. as directed by the Engineer.
6.3 SEQUENCE OF PILING The Contractor shall note that the pile shall be installed in such a sequence
that the load carrying capacity of previously installed pile is not reduced. The sequence of piling shall be
as per working drawings and/or instructions of Engineer. In a pile group, the sequence of installation of
piles shall normally be from the centre to the periphery of the group or from one side to that the soil is
restrained from the flowing out during operations.
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