絮凝−电渗法联合治理淤泥质土试验研究

针对传统电渗法治理淤泥质土过程中排水效率低且治理后土体不均匀等问题，从改变软黏土颗粒自身持水特性角度出发，提出采用新型有机高分子材料阴离子型聚丙烯酰胺（APAM）联合电渗法治理淤泥质土的思路。利用自制的一维电渗固结试验装置，探究絮凝−电渗法联合作用机制以及不同絮凝剂掺入比对电渗排水加固效果的影响规律。试验结果表明：与传统电渗法相比较，絮凝剂 APAM 的掺入减少了软黏土颗粒表面的结合水膜厚度，使得淤泥质土的前期电渗排水速率和累计排水量显著提升，从而降低了电渗法的平均能耗系数；同时，絮凝剂高分子长链的“吸附架桥”作用增强了土颗粒的黏结力和絮凝沉积效果，有效缓解了电渗过程中细小黏粒迁移集聚而造成的阴极淤堵问题；治理后淤泥质土的抗剪强度大幅增高，土体的均匀性也得到了明显改善，且当絮凝剂 APAM 掺入比为 0.30% 时，土体的电渗排水固结效果最佳。

Experimental study on the treatment of muddy soil using flocculation combined with electro-osmosis method

In order to solve the problems of low drainage efficiency and uneven consolidation effect of muddy soil during traditional electro-osmotic drainage process, a new idea of using anionic polyacrylamide (APAM) combined with electro-osmosis method to treat muddy soil was developed from the perspective of changing the water holding characteristics of soft clay particles. The self-made one-dimensional electro-osmotic consolidation test device was used to explore the mechanism of flocculation- electroosmosis method and the influence of different mixing ratios of flocculant on the reinforcement effect. The results show that APAM reduces the thickness of the bound water film on surface on soft clay particles as compared with the traditional electroosmosis method, significantly improves the early electroosmotic drainage rate and cumulative drainage of muddy soil, thus lowering the average energy consumption coefficient of electro-osmotic method. Meanwhile, the “adsorption bridging” effect of the macromolecule long chain of flocculant enhances the cohesive force and flocculation deposition effect of soil particles, which effectively alleviated the cathode clogging caused by the migration and agglomeration of fine clay particles. The shear strength of muddy soil was increased greatly after treatment, and its uniformity was also significantly improved. When the mixing ratio of the flocculant APAM was 0.30%, the highest efficiency of electro-osmotic drainage and the optimal consolidation effect of muddy soil were achieved.