FIELD TRIALS OF A NOVEL PILING SYSTEM - THE WEDGE PILE

This paper describes the results of field trials of a novel piling or anchorage system in a variety of ground conditions ranging from stiff clays through sandy soils, made ground and weathered chalk. The novel pile, known as the Wedge Pile, consists of an outer shell which is installed in the ground by driving, jacking or placing in a pre-bored hole, and is then expanded over its whole length by passing an expander mandrel through the outer shell. The tests described in this paper are for piles up to 6m in length and show that the expansion process increases the shaft friction by factors from 1.5 for clays to 9 or more for weathered chalk. Relatively small expansions of only about 10% of the pile width are required to give substantial gains in carrying capacity. Some of the piles were left in the ground for up to 9 months. The results show that the enhanced shaft resistance is permanent and that, for clay soils, an increase takes place with time. (A) For the covering abstract see IRRD 862422.