膨胀土湿胀干缩特性试验

为研究膨胀土湿胀干缩变形与含水率变化的一般规律,采用压缩仪和收缩仪对重塑膨胀土进行了无荷载条件下的分级浸水膨胀试验和收缩试验。结果表明:试样的初始干密度越大,初始含水率越小,土体的膨胀系数越大,最终膨胀率也越大;初始干密度越大,初始含水率越小,土体的收缩系数越小,最终线缩率和体缩率也越小;膨胀系数和收缩系数反映了膨胀土受含水率变化而产生变形的特性,可作为评判膨胀土胀缩性能的指标。

Experimental study on swell-shrink performance of expansive soil

The swell-shrink deformation of expansive soils results from the moisture change,and it is the main internal cause of crack propagation.In this study,the swelling deformation of remolded expansive soils under inundated conditions with different stages of the compression apparatus,and the shrinking deformation of remolded expansive soils with the shrink apparatus were tested without loads.Several relationships between the swell-shrink deformation and the moisture change were determined:the expansion coefficient and final expansion ratio have a positive correlation with initial dry density and a negative correlation with initial water content;the shrink coefficient and final linear and volume shrinkage ratio have a negative correlation with initial dry density and a positive correlation with initial water content;and the expansive coefficient and shrink coefficient reflect the deformation characteristics of expansive soils due to the moisture change and can be used as an index to judge the swell-shrink performance of expansive soils.