纳米硅对冻结黏性砂土强度影响试验研究

对加入1%纳米硅的黏性砂土进行温度-2℃、围压0.3~18 MPa的常规三轴压缩试验。试验结果表明：掺入纳米硅的冻结黏性砂土强度明显提高，在σ₃=3 MPa时强度提高甚至达到130%。将强度随围压的变化分成三个阶段：强化阶段，压融阶段，残余阶段。试验应力-应变曲线具有应变软化特性，修正的Duncan-Chang双曲线模型与其吻合良好。通过对修正的Duncan-Chang双曲线模型进行微分，分析得到初始切线模量随围压的变化可分成强化、压融和残余三个阶段。

Experimental study on the effect of nano-silicon on frozen clay sand strength

A series of triaxial compressive tests on frozen clay sand with 1% nano-silicon were carried out under confining pressure of 0.3~18 MPa at -2℃. The test results show that the strength of frozen soil with nano-silicon has a significant growth, and the proportion of growth even reaches 130% under 3 MPa. The strength changes with increasing confining pressure in three distinct phases:strengthen phase, pressure melting phase and residual phase. The stress-strain curves show strain-softening under various confining pressures. The improved Duncan-Chang hyperbolic model is taken to simulate the stress-strain behaviors and can well describe the strain-softening. Through differentiating the improved Duncan-Chang hyperbolic model, a relation between initial tangent modulus and confining pressure is obtained, which can be divided into three phases:strengthen phase, pressure melting phase and residual phase.