基于路径的非饱和土抗剪强度指标确定方法

Simplified method for determining shear strength of unsaturated soils based on different paths

非饱和土的抗剪强度是非饱和土中的基本问题,如何快速、经济地确定非饱和土的抗剪强度指标是非饱和土工程应用的关键性问题之一。非饱和土抗剪强度的黏聚力和内摩擦角是含水指标的函数;通过模拟不同路径下非饱和土抗剪试验,得到黏聚力-饱和度曲线(CDSC曲线)和内摩擦角-饱和度曲线(IFADSC曲线),进而得到非饱和土抗剪强度指标;在同一路径小区间范围内CDSC和IFADSC曲线近似为直线。通过抗剪强度路径模拟,用常规试验和含水指标得到非饱和土抗剪强度指标,大大地简化了非饱和土抗剪强度指标的确定,为非饱和土土力学理论应用于实际工程提供了有利条件。

Shear strength is a basic issue for unsaturated soil; and how to quickly and economically determine the unsaturated soil shear strength index is an important issue for the implementation of unsaturated soil mechanics into engineering. The cohesion and the internal friction angle are functions of water content index; cohesion-degree of saturation curve （CDSC） and internal friction angle-degree of saturation curve （IFAI）SC） are gotten by simulating shear experiment through different paths, through which shear strength parameters can be obtained; CDSC and IFADSC are approximating straight lines in the same path when the change of saturation degree is small. A simplified method which provides advantages for applying soil mechanics theory of unsaturated soil to practical engineering is suggested to get the parameters through simulating different paths of shear strength experiments.