It is essential and important for engineering design and maintenance to systematically investigate the physical–mechanical properties of frozen soils. At present, a series of tests have been carried out on frozen silty clay based on improved testing techniques. The results indicate that brittle and plastic failures occur for frozen silty clay under low and high confining pressures, respectively, and strengthening and weakening effects from the water content and confining pressure on the frozen strength are also observed. With the increase in confining pressure or water content, the compressive strength first increases to a maximum and then begins to decrease, and at the same time, the pressure fracturing of pore ice is gradually aggravated. Under the combination of confining pressure and water content, the microstructure evolution of frozen silty clay includes the soil particles or cementing soil crushed and reclotted, the initial soil skeleton destroyed, the pore ice fractured and melted, and the growth of microcracks, which mainly depends on the amount of water content and axial and radial loads. The tearing of cementing soil or sliding of soil particles causes drum-shaped deformation of the sample.

系统地研究冻土的物理力学特性对于工程设计和维护至关重要。目前，在改进试验技术的基础上，对冷冻粉质粘土进行了一系列试验。结果表明，在低围压和高围压下，冻结的粉质黏土分别发生脆性和塑性破坏，并观察到含水量和围压对冻结强度的强化和弱化作用。随着围压或含水量的增加，抗压强度先增大到最大值，然后开始下降，同时孔隙冰的压裂作用逐渐加剧。在围压和含水量的共同作用下，冻粉质黏土的微观结构演化包括土壤颗粒或胶结土被压碎和重新凝结，初始土骨架破坏，孔隙冰断裂融化，微裂缝的生长，这主要取决于含水量的多少以及轴向和径向负载。胶结土的撕裂或土粒的滑动导致样品呈鼓形变形。