深层搅拌水泥土墙的防渗效果分析

河道水位的骤涨或骤降使河堤两侧出现较大的水头差,极易导致管涌等渗流现象发生,直接危及着河堤的安全。该文以汕头梅溪河河堤防渗加固为例,采用深层搅拌水泥土墙的防渗措施,分别进行抽芯试验、防渗井注水试验和水泥土室内渗压实验,并用有限元软件对稳态渗流和非稳态渗流条件下河堤加固前后的渗流过程进行分析。结果表明,经深层搅拌水泥土墙处理后,土体的渗流量、渗透系数、水力坡降均有明显降低。深层搅拌水泥土墙防渗效果显著,是河堤加固防渗处理中既安全又经济的方法。

Analysis on Effect of Deep Mixing Cement-soil Cutoff Wall in Dyke

The head difference along dyke will lead to seepage problems which will threaten the security of the dyke.According to the geologic conditions and seepage analysis of the dyke along Meixi River of Shantou City,an improvement method,called as deep mixing cement-soil cutoff wall,is proposed here.To verify its feasibility and effectiveness,a series of in-situ and laboratory tests for the cutoff wall are conducted.The finite element program Plaxflow,considering the transient flow and steady flow,is also used to analyze the seepage performances of the dyke before and after reinforcement.The results show that the permeability of each soil layer has reduced greatly after treatment,and the deep mixing cement-soil cutoff wall is a safety and economic method in the reinforcing treatment of seepage control for dyke.