The Federation of Piling Specialist (FPS) is looking to members to offer a few sites to carry out trials to validate thermal integrity profile (TIP) testing as an alternative to Crosshole logging. This ‘2 Stage’ investigation follows the very well received FPS guidance on Specifying Crosshole Sonic Logging (CSL), and aims to clarify the accuracy and value of TIP testing as an alternative to CSL.

Specifically, the testing aims to investigate specific defects to establish published examples for future reference. Some work of this type has already been carried out in the USA and this information will be examined to avoid repeating specific examples where valid information already exists.

Following this initial research the FPS will move to full-scale operational testing, which will involve the construction of ‘defects’ of a known position, type and dimensions within piles. The piles will be fitted with TIP wires and tested to investigate the resultant test profile. The purpose of the defect testing is to determine what thermal resultant test profile would indicate a defect of concern. The FPS envisages these ‘defects’ being installed in non-working parts of contract piles, above the cut-off level; piles with deep cut offs are especially useful in this regard. Another example would be where test anchors are installed to say 20m long, install one anchor to 23m and introduce a ‘defect’ at the toe.

Associate member SOCOTEC has kindly agreed to contribute some testing and interpretation towards phase 2, however, the FPS does require volunteer projects from members, of both Rotary and larger diameter CFA piles. If carried out on contract piles in the way described above, there would be no impact on programme, minimal additional cost for some concrete and some wires etc.  At this stage the FPS is only looking for a small number of examples, and all results will be anonymised for safeguarding.

An FPS initiative, backed by the membership and with the input of Arup and SOCOTEC, is seen as a better way of further limiting CSL to very specific circumstances, and hopefully help to eliminate the wasteful and unsafe investigation and coring of piles which have no defects other than an anomaly caused by the CSL paraphernalia itself.

Toby Hayward is heading the subcommittee for the FPS and should be contacted through the FPS (fps@fps.org.uk).

Please respond by the end of June 2023 to indicate your participation.