دانلود Design of driven piles in sand

Abstract

Estimation of  the  axial capacity of  piles  driven  into sand involves considerable uncertainty, and design rules  are  generally not  consistent with the  physical processes involved. This Paper reviews current understanding of the factors that determine the axial capacity of piles driven into sand, and out- lines a new framework for design which takes account of  the  physical processes, is  consistent with the existing database of load test results, and is sufficiently flexible to permit refinement as new data become available. It  allows for  the  effects of confining stress on the frictional and compressibility characteristics of sand, and hence on end- bearing capacity. In keeping with field observations, shaft friction is assumed to  degrade with driving  of  the  pile  past a  particular location, from an  initial maximum value  linked to  the  local end-bearing capacity. The resulting design approach is  compared with field data, and effects of  factors such as  the  direction of  loading are  discussed.