膨胀土的浸水变形特性

Inundation deformation characteristics of expansive soils

使用压缩仪,对不同起始密度及不同起始含水率的膨胀土进行了分级浸水和一次性浸水膨胀变形试验,同时测试了试样在浸水前后不同压力下膨胀变形量的变化过程。试验结果表明,不同浸水路径在浸水的初期阶段对膨胀土的膨胀变形速率有一定的影响,但膨胀率最终值基本一致;浸水膨胀再压缩试验中压缩稳定后的膨胀率比先压缩再浸水膨胀试验膨胀稳定后的膨胀率要小,但变化较快,并随着压力的增大,加压后膨胀率逐渐减小,最终两种试验的膨胀率趋于一致;压力对不同初始含水率试样膨胀率的影响较小,对不同初始干密度试样的影响较大;在浸水单向膨胀试验过程中试样的干密度与膨胀率呈双曲线变化规律。

The swelling deformation were tested under the condition of of expansive soils with various original dry densities and water content inundated in stages or inundated with fully saturated by means of compressometer. The deformation processes of the inundated samples under different pressures were measured. The test results indicate that the swelling deformation rate in the early stage may affected by the inundation ways, but the ultimate deformation rates should be the same. The compressive test shows that the deformation rate of the pre-inundated soils is less than that of the inundated soils with preloaded pressures, but the ultimate rates of these two kinds of deformation tends to identical. The compression level has a little influence on deformation rate of soils with various original water contents but significantly affects the rates of soils with various orginal dry densities.