板土交界处裂隙发育与化学注浆时间对一维电渗固结的影响  

Influence of electrode crack development and chemical grouting time on one dimensional electroosmosis consolidation

作　　者：高程 顾佳杰 孙秀丽[1] 刘文化[1] Gao Cheng;Gu Jiajie;Sun Xiuli;Liu Wenhua(School of Environment and Civil Engineering,Jiangnan University,Wuxi 214122,Jiangsu,P.R.China)

机构地区：[1]江南大学环境与土木工程学院,江苏无锡214122

出　　处：《土木与环境工程学报（中英文）》2020年第4期67-75,共9页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51609102、51709129);江苏省自然科学基金(BK20170187)。

摘　　要：通过一维电渗固结试验,研究了板土交界处裂缝(板土脱开)与注浆时间对软土电渗固结过程的影响。采用紧序注入CaCl 2溶液和Na 2 SiO 3溶液的方式,进行注浆时间对照试验。基于沉淀或胶体和离子对电渗固结的综合效应,研究了电流、排水量、土样含水量与抗剪强度、裂缝与体缩,以及电渗能耗等随注浆时间的变化规律。结果表明:板土交界处裂隙(板土脱开)总是先于其他土体裂缝产生,板土脱开导致电流值的急剧减小是造成电渗效果下降的主要原因;一维电渗固结过程中存在板土交界处裂隙发展旺盛时间t cr,以t cr为表征指标确定最佳注浆时间,可达到最佳的电渗效益。为防止在土体中出现明显的含水量突变现象,应尽可能避免在1/3 t cr时刻前注浆,在2/3 t cr时刻注浆能够实现最佳电渗固结效果。The effects of cracks(soil disengagement)and grouting time at the interface between slab and soil on the osmotic consolidation process of soft soil were studied through one-dimensional electroosmosis consolidation test.The“grouting time”control test was performed by injecting CaCl 2 solution and Na 2SiO 3 solution in a tight sequence.Based on the combined effects of“precipitation or colloid”and“ion”on electroosmosis consolidation,the variation of current,drainage,soil moisture content and shear strength,cracks and body shrinkage and energy consumption of electroosmosis with grouting time were studied.The test results show that cracks at the interface between slab and soil(slab detachment)always occur before other parts,and the sharp decrease of current value caused by slab detachment is the main reason of the reduction of electroosmotic effect;During the consolidation process,there is a time t cr for the fast development stage of crack at the slab-soil interface.Using t cr as the indicator to determine the optimal grouting time can achievethe best electroosmosis effect.In order to prevent the obvious abrupt change of water content in the soil,it should be noted that the grouting time should be not earlier then 1/3 t cr,and grouting at 2/3 t cr can achieve the best electroosmotic consolidation effect.

关 键 词：电渗固结 注浆时间 裂缝 排水量 软土 

分 类 号：TU411.2[建筑科学—岩土工程]