Water Jetting for Sheet Piling

抄録

This project arose from collaborative research between the University of Cambridge and Giken Ltd. The primary aim of the project was to investigate the mechanics of water-jetting as an aid to press-in piling in sandy soils using controlled site testing carried out in Kochi, Japan. The experimental work was followed by analysis of the data collected, and the data analysis was complimented by a finite element model made using ABAQUS. The main findings of the research are that the rate of pile installation is heavily dependent on the jet pressure used, and that high and low jet pressures induce two different mechanisms.

The data shows that plugging within the sheet pile causes a build up of resistance at the base of the pile, preventing further penetration of the pile and causing the pile to 'stick', until enough water pressure has built up at the pile base to allow the plug to be destroyed. At this point, the pile appears to 'slip' into the soil, and the process repeats. The high water pressures are able to build up around the pile even in relatively permeable soils due to crushing of sand particles at the base of the pile forming an impermeable film.