膨胀土单向浸水膨胀时程特性试验与应用研究

Experimental research on swelling characteristics of expansive soil under one-side immersion and its application

通过膨胀土单向浸水膨胀试验,研究了单向浸水条件下膨胀土的膨胀时程特性,并运用神经网络方法对试验拟合参数进行了预测.结果表明:膨胀土的膨胀过程可分为吸水膨胀、加速膨胀和缓慢膨胀3个阶段,各阶段膨胀速率与时间呈半对数关系;试验拟合参数与初始干密度及含水量有关;利用修正的分层总和法可计算单向浸水边界条件下的膨胀土层任意时刻的膨胀变形量;通过裂隙两侧土体随时间膨胀过程的计算,可刻画出裂隙逐渐愈合的过程.

The expansion timetravel characteristics of expansive soil under oneside immersion are studied by oneside immersion swelling tests.The research shows that the swelling process can be divided into three stages, i.e. initial swelling, accelerating swelling, and steady swelling, and that the expansion rate is of a semilogarithmic relationship with time at each stage. The fitting parameters, varying with initial dry density and water content, are predicted by the neural network method. Furthermore, a method is presented to calculate the swelling deformation of expansive soil layers under oneside immersion. By calculation of the swelling process of soil at both sides of fissures, the closing process of fissures is reflected.