Bearing capacity of shallow rigid strip foundations near slopes based on generalized log-spiral shear mechanism

Abstract

In terms of five bilateral failure modes of shallow rigid strip foundations near slopes, kinematically admissible velocity fields are constructed using a generalized log-spiral shear mechanism improving the traditional failure mechanism by introducing a geometric factor. The upper-bound solution of the bearing capacity for the foundations near slopes is accordingly derived. The minimum of the five values is the required solution, and the corresponding failure mode is the accepted one. Some examples show the proposed results are fairly close to those by other theoretical and numerical methods or laboratory model tests, and in most cases the geometric parameter of the generalized mechanism is between 0.7 and 1, which means the failure mechanisms of the systems are considerably optimized. The influence of slope height, foundation depth and width, distance from the foundation to slope crest, and soil properties on the transformation among these failure modes is provided. Analysis results of many examples show that there is not rigorously linear relationship between the bearing capacity of foundations near slopes and cohesion or depth of the footing. Besides, a table of comprehensive factor expressed to reflect the slope effect on the bearing capacity for convenient applications.