黄土基坑典型区域不同含水率土体强度与变形特性研究OACHSSCDCSTPCD

The study examined the impact of moisture content and stress path on the stability of foundation pits in loess areas with the focus on the soil stress conditions during construction in three typical pit areas.Considering the significant strength differences in loess at different moisture levels,loess samples with representative moisture contents were selected for loading and unloading tests under three stress paths for comparative analysis.The results showed that by comparing the deviatoric stress peaks of three different stress-strain curves,it was found that loess demonstrated greater capacity to resist loading than axial unloading,and more so than lateral unloading.According to the strength indices,when the moisture content was 26％or above,the strength of the samples decreased significantly,exhibiting an exponential relationship.The pore pressure of saturated samples was negative at the early unloading stage,a phenomenon depicted by the Logistic function relationship between pore pressure and axial strain.The stress-strain relationships for the three stress paths conformed to a hyperbolic relationship after normalization.From it,an empirical formula for the initial tangent modulus could be obtained,and then the deformation modulus could be derived.The insights and parameters obtained from the test results could provide references for foundation pit construction in loess areas.