Work We Have Done

Three road over rail bridges with bedrock at an average depth of 8m below blinding level, but varying greatly between foundation structures. All piles were driven to refusal, which ranged between 6 and 15m on the same bridge! The access into each large pilecap was very challenging, with steep wet clayey banks. Once inside each pilecap conditions were still tight but an average production of 20 piles per day was possible. The other constand consideration on this site was the proximity to the active railway lines as well as the overhead infrastructure.

Installation and testing of driven H section piles to find the optimum embedment depth – geotechnical conditions required the use of percussively pre drilled holes for the piles in most locations, due to the presence of hard pan calcrete. The holes were drilled to 80% of the piles maximum cross-sections dimension, backfilled, and the pile sections driven to practical refusal. Direct driving was possible in areas where the wind blown sands were deeper than 1.5m, but in most cases these sands were limited to 0.5m in depth, so pre-drilling was still required.

Installation and testing of driven H section piles to find the optimum embedment depth. Limited geotechnical information was available, test pile locations were selected by the Geotechnical Investigation Consulting Engineer, and were driven to depths ranging from 1-2m. All piles were directly driven into the ground, with no percussive pre-drilling required on this site.

Very tight access piling, as close as 30cm from existing column, with limited headroom of 2.5m in places. 28 end-bearing piles, with a safe working load of 450kN, between 8-10m deep installed in 2 days on site. The site was incredibly congested, with informal traders, pedestrians and the general public.

Challenging geotechnical profile with river boulders present to a depth of 6m was no problem for the pile, driven to refusal into Mamesbury Shale, with an average rock socket of 2m. Safe working loads of between 650-950kN with a raking arrangement of piles limiting the shear load per pile to less than 20kN.

Designed for compression of 400kN, and tension of 20kN, these opened ended piles were driven to refusal, socketing into the gneiss bedrock, and generating friction from both the inside and outside of the piling tube. Large scale production with multiple rigs, up to 400 piles per day.