新开挖边坡膨胀土膨胀变形量模拟方法研究

Simulation on expansive deformation value of expansive soil of newly cut slope

膨胀土膨胀变形量的量测对边坡的变形累积研究具有十分重要的意义。新开挖边坡土样的膨胀变形受到卸载及含水率变化的综合影响,而现行规范中线膨胀率测定方法的含水率变化较小,无法模拟新开挖边坡含水率实际状态。为此,按新开挖边坡的含水率及荷载变化方式设计了模拟试验,并将试验结果与现行规范方法的结论进行对比分析。分析结果表明:采用规范试验方法测得的线膨胀量值偏高;土体位置越浅,含水率及上覆荷载的变化方式对线膨胀率的测定影响越大,对新开挖边坡土体线膨胀率的测定应考虑含水率的变化。研究结果可为膨胀土边坡工程建设提供理论支持。

The expansive deformation value play a very important effect in the study of accumulated deformation of the slope.The deformation of newly cut slope is influenced by the co-effect of unload and water content. However,the current specification method considers less water content variation in the measurement of linear expansive ratio,so it cannot simulate the practical condition of water content of newly cut slope. Aiming at a newly cut slope,we design a simulation test that is in accordance with the variation of water content and load,and compare the results from the specification method. The results show that the linear expansive ratio obtained by specification is relatively larger; the shallower the soil is,the more influence on linear expansive ratio by water content and load variation is. It is demonstrated that the effect of water content on the test of linear expansive ratio of newly cut slope should be considered.