不同形式电渗加固吹填淤泥现场试验研究

为了研究电渗法加固吹填淤泥的实际效果,同时了解电极布置形式对电渗加固效果的影响,依托具体吹填项目,采用无砂垫层真空预压联合电渗(S1)、无砂垫层真空预压联合电渗注浆(S2)和无砂垫层真空预压联合导电排水板(S3)3种类型大试验,并将S1和S3的电极分平行和错位间隔2种方式布置,现场进行5种对比小试验并对加固效果进行分析。通过分析试验数据得到:5种试验和无砂垫层真空预压法相比,土体加固后的地基承载力和抗剪强度等指标均有较大提高,土体含水率均有较大程度的降低。试验结果表明:无砂垫层真空预压联合电渗法加固地基效果比无砂垫层真空预压法好、工期短;采用真空预压联合电渗注浆(S2)比其它几种形式加固效果要好。无砂垫层真空预压联合电渗法可有效弥补无砂垫层真空预压法的一些不足,适用于对承载力和工期等有特殊要求的吹填土地基加固工程。

Field Test Study on Different Forms of Electroosmosis Reinforcementof Dredger-fill Silt

In order to investigate the practical effect of electroosmosis method in reinforcing dredger-fill silt and in the meantime to understand the influence of electrode arrangement on the reinforcement effect, we performed three types of test based upon specific dredger-fill projects. These tests include vacuum preloading without sand cushion combined with electroosmosis (hereafter referred to as S1), vacuum preloading without sand cushion combined with electroosmosis grouting (S2), and vacuum preloading without sand cushion combined with conductive drainage plate (S3). Moreover, both in S1 and S3, the electrodes were arranged in parallel and dislocated intervals, respectively. Thus, in total we conducted five tests for comparative study. The test data shows that the bearing capacity and shear strength of the foundation strengthened by the five tests have been greatly improved, and the water content of the soil has been greatly reduced. The results demonstrate that the effect of S1 is better than that of vacuum preloading without sand cushion, with shorter construction period. The effect of S2 is better than that of other test forms. Electroosmosis method combined with vacuum preloading without sand cushion could effectively remedy some shortcomings of vacuum preloading without sand cushion, and can be applied to consolidation of dredger-fill foundation with special requirements for bearing capacity and duration.