Driven Concrete Piles

SPECIFICATION 811

DRIVEN CONCRETE PILES

Copyright MAIN ROADS Western Australia

CONTENTS

ClausePage No

GENERAL

811.01Scope

811.02References

811.03 – 811.05NOT USED

PRODUCTS AND MATERIALS

811.06Precast Reinforced Concrete and Prestressed Concrete Piles

811.07Precast Composite Piles

811.08Reinforced Concrete Pile Extensions

811.09Welded Splices

811.10 – 811.25NOT USED

INSTALLATION

811.26Transport, Handling and Storage

811.27Pile Driving Equipment

811.28Pitching and Driving

811.29Driving Extended Concrete Piles

811.30Dynamic Pile Testing

811.31Temporary Compressions

811.32Final Set

811.33Acceptance of Piles

811.34Tolerances on Piles

811.35Cutting Off and Stripping Back

811.36Excess Steel Sections

811.37 – 811.80NOT USED

AS BUILT AND HANDOVER REQUIREMENTS

811.81 – 811.90NOT USED

CONTRACT SPECIFIC REQUIREMENTS

811.91 – 811.99NOT USED

ANNEXURE 811A

Pile Driving Design Assumptions

ANNEXURE 811B

Pile Driving Test Sample

ANNEXURE 811C

Acceptance of Piles

ANNEXURE 811D

Pile Driving Data

SPECIFICATION 811

DRIVEN CONCRETE PILES

1. The work under this specification consists of operations for the concrete piling of bridge foundations using reinforced, prestressed, or composite concrete, and casting reinforced concrete pile extensions, including handling, pitching and driving.

1. Australian Standards, MAIN ROADS Western Australia Standards and MAIN ROADS Western Australia Test Methods are referred to in abbreviated form (e.g. AS 1234, MRS 67-08-43 or WA 123). For convenience, the full titles are given below:

1. The precast reinforced and prestressed concrete piles shall conform to the dimensions and details shown on the Drawings. All piles shall be precast under factory conditions.

1. Manufacture of the piles shall comply with the requirements of the Concrete Institute of Australia Precast Concrete Handbook (2002) except as amended by this Specification.

1. Casting methods shall be designed to ensure that no damage occurs to the piles. The ends of all piles shall be free from any grout loss, honeycombing, cracking or spalling.

1. Formwork for piles shall conform to Specification 821 FORMWORK.

1. Reinforcement shall conform to Specification 822 STEEL REINFORCEMENT except that the tolerance on the specified cover shall be -0mm, +5mm.

1. Prestressing shall conform to Specification 824, PRESTRESSING OF CONCRETE. Strand protruding from the ends of the piles shall be cut off flush with the face and coated with epoxy resin to prevent rusting.

1. Concrete shall be class S50 and shall conform to Specification 820 CONCRETE FOR STRUCTURES except that where steam curing is proposed to be used then it shall be low pressure wet steaming. Any other form of accelerated curing shall not be permitted. Steaming shall not commence until at least two hours after the last batch of concrete has been placed. Subsequent curing shall be in accordance with Specification 820 CONCRETE FOR STRUCTURES.

1. After manufacture all piles shall be clearly marked with their length and date of casting, and meet the requirements of identification and traceability of manufactured product as specified in Specification 201 QUALITY SYSTEMS.

1. Where piles require production in segments, pile splice joints shall be cast in at time of manufacture and shall be capable of transmitting the full bending and shear capacity of the pile concrete section.

1. Composite piles which comprise precast pre-tensioned concrete with a cast in steel column section shall conform to the dimensions and details shown on the Drawings. All piles shall be precast under factory conditions.

1. Steel sections for composite piles shall be steel columns conforming to Specification 810 DRIVEN STEEL PILES.

1. Composite piles shall be manufactured in accordance with the requirements of Clause 811.06 in conjunction with the following requirements for the steel section of the pile:

(i)Cutting

(ii)End Preparation

(iii)Web and Flange Holes

(iv)Welding

1. A number of steel bars shall be joined to the steel sections by welding in position as detailed on the Drawings. All welding shall be Category SP (Structural Purpose) in accordance with AS/NZS 1554.1.

1. Qualification of Personnel

1. Weld Inspection

1. Consumables

1. Finish of Welds

1. Defective Welds

1. Reinforced concrete pile extensions shall be cast in situ and shall be either the driven or non-driven type as shown on the Drawings.

1. Formwork

1. Reinforcement

1. Concrete

1. End preparation for welded butt splices in the steel piling shall be in accordance with the details shown on the Drawings. The Contractor shall cut off the top 200mm of the pile already driven to facilitate welding of the new length.

1. Welded butt splices will be required for all pier piles and all abutments.

1. Welding shall be carried out in accordance with the relevant provisions of AS/NZS 1554.1.

1. All welds shall be category SP (Structural Purpose) in accordance with AS/NZS 1554.1. Welding shall only be carried out by welders meeting the requirements of Clause 4.1.2 of AS/NZS 1554.1.

1. For manual welding the electrodes shall comply with AS/NZS 4855. Depending on the composition of the material, Tubular cored electrodes used for semi-automatic welding shall conform to AS/NZS 17632, AS/NZS 17634, or AS/NZS 18276.

1. At least four weeks prior to commencing any welding the Contractor shall submit in writing to the Superintendent full details of his proposed welding procedures including evidence that the procedures meet all the requirements of AS/NZS 1554.1 Section 4. No departure from the approved welding procedures shall be made without the permission of the Superintendent.

1. Suitable run-on and run-off tabs shall be used for all butt welds. The tabs shall have the same thickness and preparation as the parts to be joined. Each weld pass shall terminate at least 20mm beyond the edges of the parts to be joined. Welds shall be continuous for the full length.

1. Radiographic and/or ultrasonic examination of all welds shall be carried out in accordance with AS2177 or AS2207.

1. All welds shall be examined by radiography except that if it can be shown to the satisfaction of the Superintendent that ultrasonic testing is satisfactory then 35% of welds shall be examined by both test methods and the remainder by ultrasonic testing only. The selection for the different tests shall be made by the Superintendent.

1. The Contractor shall allow for any preparatory work including cleaning the piles by wire brushing for 200mm above and below each splice to remove all mill scale and for all delays resulting from examination and approval of the welds.

1. All weld testing shall be carried out by a NATA registered company.

1. The methods of transport and handling and storage shall be such as to prevent damage to the piles as a result of impact or deflection or the application of load. During transport the piles shall be supported at the lifting points only.

1. Concrete piles shall only be lifted from the specified lifting points. They shall be lifted using either a full length steel lifting beam or two cranes.

1. No superimposed load shall be placed on the piles. However, similar length piles may be stacked provided supports are vertically above one another at the specified lifting points.

1. Temporary storage areas shall be carefully cleared and levelled. The piles shall be supported over their full width at the lifting points only. Temporary supports shall be of timber of a minimum size 150mm wide by 100mm thick and 1m long. The supports shall be on firm foundations and every precaution taken to prevent subsidence from occurring and to prevent the units bearing other than at the specified support positions.

1. Any pile damaged or distorted in excess of the tolerances as specified by AS2159 prior to pile driving shall be replaced at no cost to the Principal.

1. Piles shall be held in fixed leads such that the hammer and a braced follower follow the pile and provide support throughout the entire driving period. The use of swinging leads shall not be permitted.

1. In general the choice of the hammer shall be in accordance with the recommendations of Clause 7. 3.3.1 of AS 2159 and shall develop a rated energy of not less than that specified in Annexure 811A.

1. A helmet and packing to suit the approved hammer and pile shall be used at all times during driving. The specification for the driving dolly and packing is given in Clause 811.28.

1. At least 7 days prior to driving of piles, the Contractor shall submit details of the proposed Hammer to be used including:

1. Energy rating of hammer

1. Details of helmet and dolly

1. Mass of ram and total mass of hammer

1. Method of determining the efficiency of the hammer during pile installation.

1. Piles shall be pitched accurately in position prior to the commencement of driving.

1. Prior to driving any piles, the Contractor shall supply to the Superintendent certification that the piles comply in all respects with the requirements of the Specification.

1. Prior to driving any piles, the Contractor shall supply to the Superintendent certification that the plan position and batter of the piles comply with the requirements of the Specification.

1. Prior to driving any piles, the Contractor shall supply to the Superintendent certification that the splice complies with the requirements of the Specification.

1. The driving has been designed assuming the details shown in Annexure 811A. The Contractor should note that the packing requirement is for a minimum thickness at the conclusion of driving. To ensure compliance excess will need to be inserted at the commencement of driving and it may be necessary to replenish the packing during driving. In any event the packing shall be replaced after driving each pile or more frequently if necessary.

1. To avoid the possibility of premature ‘setting-up’ pile driving shall be continuous in the latter stages without deliberate stops except as directed by the Superintendent. Delays of as little as 15 minutes may lead to significant ‘set-up’ in piles. Where premature ‘set-up’ has occurred the Contractor shall be required to overcome this by continued driving where resistance to penetration may be significantly greater than normal.

1. The Superintendent may direct that certain selected piles be subject to a ‘set-up’ test. These piles shall be driven as specified and subsequently re-driven 24 hours after completion of initial driving. A Provisional Sum is allowed for this operation.

1. The Contractor shall record the number of blows for each 250mm of pile penetration. Details of each pile driven shall be kept on pile driving record forms as shown in Annexure 811D.

1. If any piles require extending then a reinforced concrete extension as shown on the Drawings shall be used.

1. Only the driven concrete pile extension type shall be subject to re-driving.

1. Driving of extended piles shall not be undertaken until the concrete in the pile extension has achieved the nominated strength shown on the Drawings.

1. As an audit the Superintendent will select piles as described in Annexure 811B for dynamic pile testing when the piles are close to the minimum specified set. The Contractor shall cease driving when directed by the Superintendent and provide all necessary assistance for attaching the dynamic test recording equipment to the pile. The pile shall then be re-driven.

1. The Contractor shall allow in the rates for pile driving for all necessary assistance required to carry out the dynamic pile tests and for a delay of up to five days for the tests to be carried out and the results analysed before further piles are driven.

1. All dynamic testing shall be undertaken by the Superintendent and all costs met by the Principal.

1. The Contractor shall give the Superintendent four weeks’ notice of when pile driving the test sample as described in Annexure 811B is scheduled to commence.

1. The Contractor shall take temporary compressions on a minimum of 2 piles at each foundation during pile driving. Temporary compressions will normally be taken when the pile is close to final set. The Contractor shall allow for any delays incurred in taking temporary compressions. Alternatively, the Contractor may use other means of testing approved by the Superintendent, in lieu of temporary compressions.

1. In addition to the above, temporary compressions shall be taken for each trial pile.

1. The final set of each pile shall be recorded as the number of blows required to produce a penetration of 250mm.

1. When a final set is being measured, the following requirements shall be met:

1. The exposed part of the pile shall be in good condition without damage or distortion,

1. The hammer blow shall be in line with the pile axis and the impact surfaces shall be flat and at right angles to the pile and hammer axis,

1. The hammer shall be in good condition and operating correctly and

1. The temporary compression of the pile shall be recorded, as required.

1. Minimum toe RLs for the piles are shown on the Drawings. The actual driven length may vary based on the driving performance of the piles in each particular foundation. The main criteria in the acceptance of the piles are that the minimum penetration and the minimum set as given in Annexure 811C shall both be attained.

1. Piles shall be driven to comply with the following tolerances:

1. Variation from specified position in plan±75mm

1. Variation from vertical in a 3m template±15mm

1. Variation from specified batter
   (other than vertical) in a 3m template±30mm

1. Variation in specified cut-off level±10mm

1. On completion of driving piles shall be cut-off to the levels shown on the Drawings.

1. Prior to cutting off any installed pile the Contractor shall certify to the Superintendent that all acceptance criteria of the pile and the tolerances on the pile comply with the requirements of the Specification and the Drawings.

1. Composite and prestressed concrete piles shall be stripped back to the extent shown on the Drawings to expose the reinforcement and prestressing strands. Only hand held equipment shall be used for this operation.

1. Prior to stripping back the heads of prestressed concrete piles a 20mm deep saw cut shall be made on all sides of the pile at cut-off level. Due care shall be taken to avoid splitting of the permanent concrete during the stripping operation.

1. After completion of all pile driving, excess steel piles shall be disposed off site by the Contractor.

ANNEXURE 811A