By Bengt B Broms, Royal Institute of Technology, Stockholm and Christer Badholm, Balken Piling
This paper was first publsihed in GE’s July 1976 issue.
One of the largest pile-driving jobs on which high capacity precast reinforced concrete piles have been used in England has been that at the Thames Refinery project on Canvey Island, Essex. More than 8000 piles (275 x 275mm in cross-section) were driven by Balken Piling, of Derby to support six oil tanks each having a capacity of 83300m3. The selected allowable load on the piles, 7 tons (0.75MN), was based on results from borings, soundings and pile load tests.
This article describes the design, driving and control of the precast piles as well as load tests on piles installed with and without enlarged points. By means of a “tell tale” system it was possible to separate the skin friction from the point resistance for some of the loaded piles.