不同初始状态下压实黄土浸水后的变形特性研究

Deformation behavior of compacted loess with different initial states after wetting

以压实黄土为研究对象,通过一系列浸水后的压缩变形试验研究了不同初始含水率、初始干密度和竖向压力对非饱和压实黄土浸水后变形特性的影响.结果表明:非饱和压实黄土在相同竖向压力条件下,浸水压缩稳定后的状态与初始状态无关;压实黄土浸水后产生压缩变形的起始点压力值主要受试样初始干密度影响,而终止点压力值主要受初始含水率影响.其次,根据不同初始状态非饱和压缩曲线的相互关系,给出了考虑初始含水率和孔隙比影响的屈服应力计算方程.最后,基于非饱和压实黄土浸水前后的变形特性,提出了定量化描述压实黄土浸水后压缩变形起始点和终止点压力值的计算模型.

In this paper,a series of wetting tests on unsaturated compacted loess were performed to investigate the deformation behavior after wetting.The influences of different initial water contents,initial dry densities and vertical pressures were studied.The results indicate that under the same vertical pressure,the state of unsaturated compacted loess after wetting is independent of the initial states.The vertical pressure of the initial point after wetting is mainly affected by the initial dry density,while the vertical pressure of the termination point is mainly affected by the initial water content.According to the relationship of the unsaturated compression curves with different initial states,a yield stress equation considering the influence of initial water content and void ratio is proposed.Finally,based on the deformation behavior of unsaturated compacted loess before and after wetting,a simple method that can quantitatively describe the vertical pressure values of the initial point and the termination point is proposed.