吹填软弱土夹层的真空预压加固方法探讨

Discussion on vacuum pre reinforcement method of dredger fill soft soil interlayer

天津沿海地区围海造陆通常采用淤泥质土,由于水力分选和吹填工艺的原因,易形成软弱土夹层,对新吹填土真空预压加固效果产生不良影响,产生加固后无法达到使用要求的现象。文章通过分析吹填软弱土夹层的形成原因及其含水量大、压缩性高、抗剪强度低和渗透性差等特性对加固效果的影响。根据沉积时间的不同,探讨了3种处理方法:吹填砂性土法,二次真空预压法和深浅排水板结合处理方法。并结合3个典型工程实例,论述了3种方法在工程中的成功应用。

Tianjin coastal areas usually used the silt soil for reclamation. Because of the hydraulic sorting and reclamation process, it was easy to form weak soil layers, which has a harmful effect on the vacuum preloading con-solidation and would make the soil cannot meet the use standard after reinforcement. In this paper, the forming rea-son of reclaimed soil weak interlayer was analyzed, and the influences of its water content, high compressibility, low shear strength and poor permeability characteristics on reinforcement effect were studied. Depending on the deposi-tion time, three methods were discussed, including blown sand filling method, secondary vacuum preloading method combined with depth drainage plate processing method. Combining with three typical examples, the three approach-es which have the successful applications in engineering were discussed.