红黏土浸水变形特性试验研究

An experimental study of deformation characteristics of lateritic clay due to wetting

对广西桂林红黏土进行了浸水饱和引起的膨胀变形和压缩变形试验,在竖向压力25-800 kPa范围下,研究了不同初始含水率和干密度对浸水变形特性的影响。结果表明：浸水饱和引起的压缩变形量主要取决于初始干密度,而初始含水率对其影响较小;在相同的含水率下,浸水压缩变形量随着干密度的增加而减小。把各组的固结状态线和浸水饱和稳定后状态线的交点称为分界点。初始含水率对分界点的影响较小,而随着干密度的增加,分界点右移,即浸水膨胀区域增大,浸水压缩区域减小。由分界点可得出了介于浸水膨胀和浸水压缩的分界状态线,从而可以判定不同孔隙比、不同竖向压力下土样会产生浸水膨胀还是压缩。最后,基于浸水变形试验结果,可以计算压缩区红黏土试样在不同竖向压力下浸水压缩变形量。

A series of wetting tests on a lateritic clay taken from Guilin, Guangxi, were conducted to investigate the swelling and compression deformation during wetting. The influence of different initial water contents and initial dry densities were examined under the ranges of applied pressures from 25 KPa to 800 KPa. The results show that the swelling deformation due to wetting is mainly affected by the initial dry density, and is hardly affected by the initial water content. At the same initial water content, the swelling deformation increases with the increasing initial dry density. According to the intersection points of the compression cures at the unsaturated state and the saturated state lines with different initial densities, we can obtain a state line, with which we can identify if the expansive soil shows swelling or compression due to wetting at the specific pressure. The compression deformation at different vertical pressures due to wetting can also be calculated.