冻土静止侧压力系数的试验研究

The Experimental Study on Coefficient of Lateral Earth Pressure at Rest for Frozen Soil

在土力学中,静止侧压力系数(K0)是一个重要的力学参数。对于融土,K0同土的干密度、土质和受力历史等因素间存在着密切的联系;对于冻土,由于土中冰的存在,K0同温度间也存在着紧密的联系。本文对两种不同土质的冻土样进行了K0试验,研究表明温度、干密度、土质以及受力历史均同冻土的侧压力系数存在着独特的内在联系。根据试验结果,K0同温度、粉粘粒含量和加载次数成正比而与干密度成反比;同时,由这些因素导致的K0的差异会随着轴压增大而逐渐减小。另外随着冻土温度的降低,受力历史对K0的影响也逐渐增大。因此,在工程计算分析中应充分考虑这些因素对侧压力系数的影响。

The coefficient of lateral earth pressure at rest（K0）is an important parameter in soil mechanics.For unfrozen soils,K0 is closely related to dry density,grain size distribution and stress history;for frozen soils,K0 has a close relationship with temperature due to the existence of ice.This paper carried out K0 tests for two kinds of frozen soils with the different conditions of temperature,fine grain size distribution,loading times and dry density.According to the results,K0 is proportional to temperature,fine grains content and loading times and inversely proportional to dry density.Meanwhile,the K0 difference caused by those factors will decrease when the axial pressure increases.In addition,the pressure history effect on K0 will be strengthened as temperature decreases.Hence,in the calculation of frozen ground engineering,the effects of temperature,dry density,grain size distribution and pressure history on K0 must be taken into consideration.