HSE are becoming seriously concerned about hand arm vibration while breaking down piles. Members of the Federation of Piling Specialists have experienced difficulties with HSE Inspectors in some regions even when the client has been offered, and refused, the use of a debonding system.
The FPS will be preparing guidance about breaking down piles for publication on their website, and are about to publish the following information on the use of debonding systems:- ” Reinforcement debonding, or any other items attached to the pile reinforcement, can only be placed in the pile to the same tolerances as the pile reinforcement. These tolerances are given in the ICE Specification for Piling and Embedded Retaining Walls 1996. Engineers/Specifiers should therefore specify the same tolerances for pile cut-off-level if such systems are to be used.
· Before specifying reinforcement debonding, or any other related systems, discussions must take place with the piling contractor in order to investigate the practicality of the proposed system for the chosen piling technique, pile size, the prevailing ground conditions. This technique is not universally applicable.
· Any system installed should be protected from damage, otherwise the system may lose all intended benefits. For example, the debonding of bars will not be effective if the bars are bent during or after installation.
· The lifting point for the removal of the concrete over the debonded length should be designed and specified by the main contractor following discussions with the piling contractor.
Consultants should be aware of their responsibilities under CDM and advise clients accordingly.