湿—载—冻—融作用对洛川黄土三轴剪切强度影响

Experimental Study on the Shear Strength of the Three Axes of Luochuan Loess with Wet-cold-freezing and Thawing

为了研究湿、载、冻、融作用对洛川黄土三轴剪切强度的影响,运用GCTS电液伺服低温高压动态三轴测试系统,进行了不同含水率、冻结条件、融化条件下的三轴剪切实验,研究含水率、载荷、冻结、融化联合作用对黄土强度的影响及其作用机理。实验结果表明,土中水通过对土颗粒联结作用的影响改变黄土的强度特性,冻结作用通过温度对土中自由水的相变结冰,改变土体承受外力的结构,从而对土体的强度产生影响,融化作用主要是由于冻结过程中土中水的体积膨胀对土颗粒联结的损伤和破坏,从而使黄土的强度会产生较大的下降。

In order to study the influence of humidity,loading,freezing and thawing effect of three axis shear strength of the Loess in Luochuan, using the GCTS electro-hydraulic servo dynamic testing system of low temperature and high pressure three axis,the different moisture content,freezing conditions,the three axle shear experimental melting conditions,the effects of moisture content,loading,freezing,melting effect on joint action the strength of loess and its mechanism. The experimental results show that the strength characteristics of soil water through the effect of coupling to the soil particle changes of loess,frozen through the phase transition temperature of free water in the soil freezing soil,change the external force structure,and thus affects the strength of soil,thawing effect is mainly due to the freezing process of soil water volume expansion on soil particle joint the damage and destruction,so that the strength of loess will greatly decrease.