侧限条件下原状黄土增湿特性研究

Study on moistening characteristics of original loess under lateral confinement

目前,对侧限条件下原状黄土增湿过程中的变形和持水特性研究还较少。以新疆伊犁原状黄土为对象,采用固结仪开展了不同竖向压力作用下的分级增湿试验和湿陷试验。在分级增湿试验中,研究了增湿过程中持水特性以及静止土压力系数的变化规律,提出了侧限条件下土水特征曲线模型以及静止土压力系数的表达式;引入"增湿水平"这一变量描述土体的含水状态,研究了增湿变形与增湿水平的相关关系。最后通过比较增湿试验(单线法)和湿陷试验(双线法)所得到的增湿水平与增湿变形系数关系曲线,验证了两种试验方法在黄土增湿变形研究中的等效性。

At present,studies on the characteristics of original loess deformation and water retention in moistening process under lateral confinement are relatively few. Focusing on the original loess from Yili,Xinjiang Region,we performed stepped moistening and collapsibility tests on original collapsible loess under different vertical loads by consolidometer. In the stepped moistening tests,we explore the changing patterns of static earth pressure coefficient and water retention behavior of collapsible loess,and propose the expression of static earth pressure coefficient and soil-water characteristic curve of laterally confined original loess. Then,we present the concept of moistening level to describe the moistening condition of loess,and the correlation between moistening level and moistening deformation is studied. Finally,the equivalence between single-line method（ moistening test）and double-line method（ collapsibility test） is verified by comparing the relation curves of the moistening level versus the moistening deformation coefficient.