STUDY ON SHEAR STRENGTH AND STABILITY OF UNSATURATED SOILS UNDER FOUNDATION EXCAVATION

摘要

This paper discusses the stress path characteristics of the slope soil under foundation excavation. The practical stress paths in the foundation slope soils have been simulated by a triaxial test machine and the properties of the shear strength of unsaturated soil samples are tested. The results show that the shear strength of the unsaturated soils is decreased at different depth and different distance from the wall of excavation because of the stress release or lateral unloading in slope soils. And the experimental study indicates that the difference of the shear strength is obviously changeable with the water content or saturated degree of the soil. Using the slope stability evaluation model for unsaturated soils and considering the strength indexes of disturbed slope soils and the matric suction, the slope stability of a practical foundation is analyzed. The result is useful in the stability evaluation of unsaturated soils.