黏土孔隙可溶盐组份对黏土结构热–力学行为的影响

土中液相是土体结构中非常活跃的部分,它可以通过土中孔隙溶液组份的析出与颗粒矿物的溶入来改变粒间的连接,进而影响土体的结构强度。通过室内模拟试验,改变黏土结构孔隙中溶液组份的种类和含量,讨论土体孔隙中不同可溶盐组份在热作用下的力学表现,研究热作用下孔隙溶液组份及含量对黏性土结构力学行为的影响。试验结果表明,当环境温度由40℃升高到60℃,热作用时间为168 h时,加入FeCl3组份的黏土黏聚力c增幅最大,其次是Fe和MnSO4,加入MgCl2组份的增幅不大,而加入Ca(OH)2组份的黏聚力c反而减小;相同条件下,加入FeCl3和Na2S2O4组份黏土的内摩擦角φ是减小的,加入Fe和AlCl3组份的变化不大,而加入MgCl2和Ca(OH)2组份后,黏土的内摩擦角φ增幅相当,仅次于浸泡去离子水后的数值。结果认为,黏性土中孔隙水溶液组份是影响黏性土热敏性的重要因素。

Influence of soluble salts of clay structural pore on thermodynamical behavior of soils

The liquid phase,a very active part in the soil body,can change the connections among particles through the isolation of solution ingredient in the pore and the dissolving of granular mineral,then influence the structural intensity of the soil body.Based on the laboratory test that changes the kind and content of the solution in the clay structural pore,the mechanical behavior under thermal effect of different soluble salt ingredients in the soil structural pore is discussed.The influence of ingredients and content of pore solution on structural and mechanical behavior of viscous soil under thermal effect is studied.The test results show that when the temperature increases from 40℃ to 6 0℃,the time of thermal effect is 16 8 h,the cohesion of the clay added MgCl2 ingredients has the greatest increasing range,followed by that of the clay added Fe and MnSO4 ingredients,and that of the clay added FeCl3 ingredients has a little increasing range.On the contrary,the cohesion becomes smaller after adding Ca(OH)2.Under the same condition,the internal friction angle of the clay added FeCl3 and Na2S2O4 ingredients is reduced,the group added Fe and AlCl3 has a little change,and the increasing range of clay added MgCl2 is similar to that added Ca(OH)2,second only to the clay soaked with deionized water.