SPI Piling Ltd, were employed to design and install a large sheet piled cofferdam, which was to form a water tight box so created a water feature within a new residential development.
The cofferdam was originally designed on a U shaped piles however SPI Piling, offered a Z shaped alternative which had two main benefits:

* Z piles were supplied in pairs so significantly reducing the number of piles that had to be initially pitched and driven: 435nr U piles down to 187nr Z pairs.

* The number of interlocking clutches is greatly reduced so improving the seal of the cofferdam: 435nr U clutches down to 372nr Z pairs.

The piles were initially driven as far as possible with our ABI TM 14/17 Telescopic Leader Rig and resonance free vibrating hammer in to the firm to clays.

As the client was after a seal between the piles and the ground they were driven in to. no pre-augering in advance of installation was permitted.

For the last 2m of driving an HPH2400 impact hammer was mounted on the leader rig instead of the vibrating hammer and the piles were driven down to finished level so giving our client the seal they required.

Completed on time, to original budget.