冻融循环作用下重塑黄土强度劣化试验研究

Experimental Study on Strength Deterioration of Remolded Loess Under Freeze-Thaw Cycles

以青海省东部地区的黄土为研究对象,分别对不同含水率、干密度下的重塑黄土在冻融循环后进行剪切试验。结果表明:黄土的黏聚力和内摩擦角均随着冻融循环次数的增加产生了劣化;黏聚力在第1次冻融循环后劣化效应强烈,经过3～5次冻融循环后黏聚力变化趋于稳定状态;内摩擦角随着冻融循环次数的增加呈增大趋势。分析了在不同冻融循环次数下含水率、干密度对重塑黄土强度影响的过程与机理,并建立了黄土强度参数和冻融循环次数的函数关系式,反映重塑黄土在冻融循环作用下强度劣化规律。

Taking the loess in eastern Q inghai as the research object,the shear tests for remolded loess with different water contents and different dry densities were conducted after the freeze-thaw cycles.The results show that the cohesion and internal friction angle of loess deteriorates with the increase of freeze-thaw cycles,the cohesion deteriorates strongly after the f irst freeze-thaw cycle and tends to be stable after 3~5 freeze-thaw cycles,and the internal friction angle increases with the increase of freeze-thaw cycles.The effect progress and mechanism of water content and dry density on the strength of remolded loess under different freeze-thaw cycles were analyzed,and a function formula of loess strength parameters and freeze-thaw cycles was established,which ref lects the strength deterioration law of remolded loess under freeze-thaw cycles.