黏土-结构接触面大剪切变形后渗流特性试验研究

Experimental study of seepage characteristics of clayey soil-structure interface under large shear deformation

黏土-结构接触面易产生大的剪切变形,且由于场地、施工等原因,接触面部位可能存在填筑缺陷、杂质等情况,这些因素均可能对其渗流安全产生不利影响。本文采用一种接触面剪切渗流试验装置,对黏土-结构接触面大剪切变形后的渗流特性进行了试验研究,重点模拟了接触面存在填筑缺陷及含有杂质两种工况下的渗流特性,并与均质黏土接触面渗流特性进行了对比,同时对接触面正应力、剪切变形、水力坡降的影响进行了分析。结果表明:含有填筑缺陷的接触面在大剪切变形过程中渗透性降低;而含有粉土杂质的混合黏土接触面,其渗透性起初随剪切变形的增加而减小,剪切至某一程度后反向增加;存在填筑缺陷和杂质的接触面渗透性强于均质黏土接触面。

Large shear deformation often occurs in the clayey soil-structure interface; and some defects and impurities near the interface may affect the seepage safety. By using a seepage test device for interface, seepage characteristics of clayey soil-structure interface under large shear deformation were studied. The conditions of the interface with construction defects and impurities were simulated and the seepage characteristics were compared with that of homogeneous clayey soil. The effects of normal stress, shear deformation and hydraulic gradient were analyzed. The results show that the permeability of the interface with defects decreases with large shear deformation; while the permeability of the interface with impurities decreases with shear deformation increase at the beginning and then increases after a certain shear deformation. The permeabilities of interfaces with defects and impurities are higher than that of homogeneous clayey soil.