The Effect of Pile Permeability on the Stress Changes Around a Pile Driven into Clay

摘要

Previous studies of stress changes for piles driven into clay soils are reviewed and their conclusions discussed in relation to piles of finite permeability. A modified analytical solution for radial consolidation in an elastic soil is presented for the case of a highly permeable pile (i.e. zero excess pore pressures at the pile-soil interface). The solution shows that consolidation of the soil occurs significantly faster than for the case of an impermeable pile. Isochrones giving the variation of excess pore pressure with radius from the pile at different times after driving, are compared with results from finite element analyses for non-linear soil models. It is shown that the stress path followed by soil next to a permeable pile during consolidation leads to higher final effective stresses than for an impermeable pile. Use of the Cam-clay soil model enables the radial distribution of final water content of the soil to be estimated.