化学电渗法加固软黏土地基对比室内试验研究

Laboratory tests on soft ground improvement by chemical electro-osmosis method

基于室内试验方法,开展了阳离子摩尔量、CaCl2和Na2SiO3化学作用等因素对软黏土电渗排水及加固效果的影响规律研究;实测了化学溶液联合电渗试验中排水量与排水速率、土体导电性、能耗以及试验结束后土样含水率、抗剪强度的分布规律,并开展了常规电渗试验作为对比分析。研究结果表明,增加土样中阳离子摩尔量,是增加电渗排水量、提高排水速率及缩短电渗时长的有效方法之一;与常规电渗试验相比,联合注入CaCl2和Na2SiO3溶液的土体平均抗剪强度提高了约120%,较单独加入Na2SiO3或CaCl2溶液多提高约20%;联合注入CaCl2和Na2SiO3溶液对改善电渗处理后土体含水率和抗剪强度分布不均问题作用明显。

Based on the laboratory test method, the improvement effects of soft ground influenced by molar amount of cation, chemical action of CaCl2 and Na2SiO3 are investigated. The distributions of drainage rate, soil conductivity, energy consumption, soil water content and shear strength after different tests are analyzed comparatively. For comparative analysis, the laboratory tests on soft ground improvement by the traditional electro-osmotic method are also carried out. The test results show that the increasing molar amount of cations in soft clay is one of the most effective methods to increase the drainage amount, to improve the drainage rate and to shorten the electro-osmotic duration. The average shear strength of soil treated by the combined injection of CaCl2 and Na2SiO3 is increased by about 120%, and nearly 20% higher than that of injection of CaCl2 or Na2SiO3 lonely. The combined method of CaCl2 and Na2SiO3 has significant effect on improving the uniform distribution of water content and shear strength of soft clay after chemical electroosmotic treatment.