关键词: 崩岗, 抗剪强度, 灰色关联度分析法, 花岗岩残积土

Abstract:

Granite residual soil, characterized with special soil mechanical properties, is widely distributed in the south of China. Investigation of the spatial variability of the shear strength of granite residual soil in vertical profile and its influential factors can provide significant values for guiding excavation construction and explaining the occurrence of collapsing hill. The basic characteristics of the granite residual soil sampled at different elevations of vertical profiles were tested and the shear strength of vertical profile and its variability were studied. It is found that there is a significant difference in vertical shear strength at different levels, which is especially reflected by the variation of the internal friction angle; soil moisture and sand content play a prominent role in granite shear strength. When soil moisture content and sandy particle content are both considered as variables, the shear strength increases as the soil moisture declines and sand content increases; the soil cohesion increases with the decrease of soil moisture content, but decreases with the rise of sand content; the internal friction angle demonstrates an upward trend with the decrease of water content and increase of sand content.

Key words: collapsing hill, shear strength, grey relational analysis, granite residual soil