3. PILE WORK
3. 1 Preamble 3.1.1 Scope of work
The work comprises
supplying of labor, materials, plants, equipment, temporary huts and all other
items necessary for the design and installation of the piles as shown on the
drawings and described in these specification.
The work is to be executed in
accordance with specification and contract documents and to the satisfaction of
the Engineer. All tenders shall therefore furnish information about the type of
piles they specialize in and other relevant details of design, execution,
equipment, testing, etc, complete, in support of their capabilities.
whole of the work and materials shall conform to the current edition of relevant
British standards and codes of practice.
3. 1. 2 Responsibility for design and
The piling contractor will be responsible for designing
installing the piles to satisfy the performance requirements and minimum
design criteria laid down in these specification lie shall provide all necessary
details and information to satisfy the Engineer who designed the foundations
that his proposals will meet the specification. It will also be his
responsibility to produce standard workmanships in the best possible manner, to
effect the design in the actual conditions encountered on the ground or below .
In particular he shall make whatever day to day minor modifications to the
agreed proposals that may be found to be necessary to cater for minor variations
in ground conditions. Any variations from the agreed principle shall be in
accordance with the Engineer's approval.
1. 3 Site conditions
The piling contractor will be deemed to have
visited and inspected the site and surroundings before preparing his tender and
to have made himself thoroughly acquainted with all details of the site,
including those not specifically mentioned herein or on the
3. 1. 4 Existing services and
The piling contractor will be responsible for any
claims arising from damage to services or to adjacent structures or property, at
the time of executing the work.
3. 1. 5
Pile length for purpose of payment
The length of each pile for
purposes of payment shall be measured in accordance with the standard method of
measurement for building and civil engineering work.
3. 1. 6 Records
The piling contractor shall
keep on site a complete record of the changes in the nature of the strata
through which each passes. Such records shall be made available for inspection
by the Engineer during the progress of the piling contract and copy shall be
supplied to the Engineer at the completion of piling work .
3. 2 Design
The pile is designed to carry as
its part of the total support of the foundation loading. Specified in the
3. 2. 1
As stated in 3 .1.2, the piling contractor will be
responsible for designing the piles and producing a piling that can carry safely
the loads indicated on the foundation plans.
3. 2. 2 Approval of Design
the piling contractor's tender, the Engineer will be required to satisfy himself
that design proposals are sound and reasonable* To this end the piling
contractor shall submit any calculations or supporting evidence which the
Engineer may call for after receipt of tender .
3. 3 Concreting Materials and
3. 3. 1
cement, aggregate and water to be used shall be in
accordance with the requirement of section ( 4-2 ) "concrete work". The piling
contractor shall submit details of reinforcements included in his design and
tender. All reinforcements used in the piles shall be as per the approval of the
Engineer and in accordance with section ( 4- 2) .
3. 3. 2 Concrete
The concrete mix shall be
designed by the piling contractor to suit the piling system adopted and shall be
dry as possible consistent with that system , and the method of compaction.
However, the minimum cylinder strength at 28 days shall be 211 kg/cm2.
3.3.3 Placing and compacting
shall be placed in its final position as soon as possible and in any case not
later than half an hour after mixing. Ready mix concrete must be placed
immediately it leaves the mixing truck. The method of placing shall be such as
to ensure that the concrete in its final position shall be dense and
homogeneous. Concrete shall not be ordinarily placed under water. If water is
present within the pile-shell a sealing group of approved quality shall be
placed in the bottom of the shell for 1 to 1-2 m depth, the water shall then be
pumped from the pile and concrete placed in the dry. Adequate precautions shall
be taken to ensure that water leaking out of concrete shall not build up on top
of it during the pouring of Concrete in pile shaft, and any such water shall be
removed before more concrete is placed in the shaft, The pile shall be concreted
in one continuous operation. If the continuity of placing the concrete is
interrupted no further concrete shall be placed without the prior approval of
the Engineer. The method of compaction shall be proposed by the contractor and
approved by the Engineer before placing concrete .
Concrete shall be transported from the mixer to the position of
the pile in such a manner that segregation of the mix shall not
3. 4 Piling
The main contractor will provide the piling contractor with all
necessary layouts and take responsibility for their accuracy and check that the
piling contractor executes the work in accordance with these layouts. The piling
contractor shall set out the position of each pile.
The maximum permissible
positional deviation of the center of each finished pile from the correct center
point shown on the setting out drawing is 75 mm in any direction. The maximum
permissible deviation from the specified inclination of any finished pile is
2-2.5 % .
The piling contractor shall bear the cost of any additional work
which, in the opinion of the Engineer, may be necessary due to any pile being
installed in apposition not within these tolerances.
3.4.3 Temporary lining
shall be taken including the use of a temporary lining tube, water bearing or
unstable strata, to prevent the ingress of water, to maintain any pile
excavation to its full dimensions and to ensure that the pile shaft shall be
formed to its full cross-sectional area, where there is a temporary lining it
must be removed in the line of the pile in such a manner that no defect or
damage will be sustained by the pile.
The depth to the average levels of the
concrete surface of the pile shall be checked before and after any temporary
linings are with draw. These measurements shall be recorded.
3.4.5 Drilling Mud
Drilling Mud may be
allowed only with prior permission of the Engineer and subject to the piling
contractor providing satisfactory evidence that its disposal will not foul or
contaminate any part of the site or surrounding areas or services.
Cleaning the Excavation
Upon completion of any boring, the excavation shall
be cleaned of all losses, disturbed and remolded soil to expose a dry base of
After the tube has been installed in its final position,
the Engineer will inspect the tube for proper plumb, location and other
conditions. Only after his approval can the contractor proceed further in
placing reinforcement and concreting the pile.
3.4.8 Jetting and pre-boring
pre-boring may be used only with the prior permission of the
3.4.9 Backfilling empty
Where trimmed level of any pile is more than 600nm below the
starting level of the piles, empty boring shall be backfilled as soon as
possible with sand of colour which contrasts with the surrounding natural soil
3.4.10 Cleaning the site
piling contractor shall remove from the site at intervals during the operation
of the work, and on completion, all unnecessary plant, rubbish, water and debris
resulting from his activities.
Tests of completed piles shall conform to British standards CP
3.5.1 Notice of
The Engineer shall be given at least 40 hours notice
before the commencement of each test .
3.5.2 Supervision of pile tests
contractor shall Keep the tests under continuous and competent supervision to
the satisfaction of the Engineer, All necessary facilities shall be provided to
enable the Engineer to check reading during the progress of the tests.
3.5.3 Testing assembly
The piling contractor
shall submit complete details of the testing assembly and all details of the
proposed arrangement and procedure for test loading for approval of the Engineer
before the installation of tension piles. The details shall include a complete
list of all equipment being used in the test, including manufacturer's name and
the reference number of the equipment.
At the conclusion of work each day the piling contractor
shall send to the Engineer a copy of his daily record sheet . The piling
contractor shall also send to the Engineer within one week of the completion of
each test, two copies of all record graphs and results of laboratory and in-situ
tests conducted on the installation and testing of all trial piles. This
information shall include a load Settlement, diagram plotted to scales
3.5.5 Failure of contract test
In the event of a contract the failing to satisfy the test
requirements the piling contractor will be instructed to test additional
The piling contractor shall bear the cost of all additional and
consequential work as the Engineer may consider necessary due to the failure on
one or more piles, to satisfy the requirements of the loading test .
3.5.6 Rejection of piles
reserves the right to reject any pile which in his opinion is not structurally
sound, or is not in a proper position and alignment. The contractor shall be
bound to pull out same and re-drive a new pile in its place , or leave the
defective piles install at the contractor's cost one or more additional pile as
per the directions of the Engineer in writing.
3.6 Other Pile Types
3.6.1 Steel piles
The work covered by this
clause consists of furnishing all materials, labor and equipment and performing
all operations for driving and completing steel piles as indicated on the
drawings, in addition to driving and testing the test piles, all in accordance
with the specification and as directed by the Engineer.
Steel piles shall be of the
type and weights shown on the drawings and shall be manufactured from steel
conforming v to ASTM-A36. All piles shall be straight and true to section and
any pile which in the opinion of the Engineer, is defective in any way, shall be
rejected and shall be replaced by the contractor.
3.6.3 Driving steel piles
Steel piles shall
be driven vertically or inclined to true position and secured against lateral
movement by leads or other suitable means approved by the Engineer, All piles
driven out of line, but of plumb, with incorrect inclination, or twisted, broken
or bent, otherwise damaged in driving shall be withdrawal and replaced with
other piles, properly driven to the true position and alignment required and to
the satisfaction of the Engineer. All piles shall be cut off at the levels
indicated on the drawings . A steam hammer shall be used to drive the piles
unless other equipment is permitted by the Engineer. Piles may be driven by a
hammer and water jets or by water jets alone. An ample supply of water at
adequate pressure shall provided. Piles shall be driven by hammer alone for the
last 1.5 m of penetration, piles shall be driven to depths or to penetration per
blow as directed by the Engineer. Accurate records of the penetration per blow
for the last 30 cm shall be kept for the guidance of the Engineer in determining
allowable loads on the pile.
If proper resistance to driving is not attained
at the predetermined length of pile, or when the length of piling required is in
excess of the largest continuous length that can be supplied, an additional
length of piling shall be added by butt welding. The joint details shall be as
shown or as directed and fulfilling the requirements of AISC standards.
contractor shall take all the necessary precautions to prevent any damage to the
existing properties due to the piling work.