Investigation of At-Rest Soil Pressures due to Irregular Sloping Soil Surfaces and CSOILP User's Guide

摘要

At-rest pressures for horizontal soil surfaces are traditionally estimated by applying at at-rest pressure coefficient to the effective vertical pressure. No method for estimating at-rest pressures has gained general acceptance when the soil is not horizontal. The use of elasticity solutions to account for the effects of surface surcharge load on active and passive pressures for design of retaining walls is common. A proposed method of estimating the at-rest pressures due to a sloping surface is evaluated by making comparisons with the results from incremental nonlinear finite element analyses. The proposed method consists of treating the weight above a horizontal datum as a surcharge load and evaluating load and evaluating the contribution of the surcharge to the pressures below the datum using appropriate theory of elasticity solutions for surface loads on a semi-infinite elastic medium. Various soil geometries of one and two layers consisting of sand and clay are analyzed and the results used to calibrate the proposed method. A computer program is presented that automates the calculations to compute the at-rest earth pressures due to irregular soil surfaces.