膨润土泥饼渗透系数及对隔离墙渗透性的影响分析  

Hydraulic conductivity of bentonite filter cake and its impact on permeability of cutoff walls

作　　者：潘倩[1,2] 陈云敏[1,2] 李育超[1,2] 文一多 

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058 [2]浙江大学建筑工程学院岩土工程研究所,浙江杭州310058

出　　处：《浙江大学学报（工学版）》2017年第2期231-237,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家"973"重点基础研究发展计划资助项目(2012CB719800);国家自然科学基金资助项目(51378465);浙江省公益技术应用研究资助项目(2016C31G2010015)

摘　　要：为了研究防污隔离墙膨润土泥饼的渗透系数,采用美国石油协会(API)压滤试验方法,根据实际工程泥浆沟槽中水压力差范围,测得压滤压力为20~80kPa工况下膨润土泥饼的渗透系数为4.0×10-10~1.3×10-9 m/s,比在压滤压力为69~690kPa工况下得到的泥饼渗透系数大1~2个数量级.将得到的泥饼渗透系数应用于分析隔离墙等效渗透性,分析了泥饼渗透系数、泥饼厚度和墙体材料渗透系数对隔离墙渗透性的影响,结果表明:当墙体材料渗透系数较大(大于等于1.0×10-7 m/s)时,隔离墙渗透性主要受泥饼参数控制;隔离墙渗透系数随墙体材料渗透系数的增大而增大,但由于泥饼厚度小且渗透性低,隔离墙渗透系数会趋近于一极限值.The American Petroleum Institute（API）fluid loss test was applied to investigation of hydraulic conductivity of bentonite cake in cutoff walls.According to the hydraulic pressure in field,20 kPa to 80 kPa was used in compression pressure to estimate the hydraulic conductivity of bentonite cake.The measured hydraulic conductivity ranged from 4.0×10-10 m/s to 1.3×10-9 m/s,which is 1to 2magnitude larger than those obtained at the pressure of 69 kPa to 690 kPa.The hydraulic conductivity of filter cake was applied to analyze the equivalent permeability of cutoff wall.The impacts of hydraulic conductivity,and thickness of filter cake and hydraulic conductivity of backfill on wall permeability were analyzed.It can be concluded that permeability of cutoff wall is controlled by filter cake when the hydraulic conductivity of backfill is high（equal or greater than 1.0×10-7 m/s）;the permeability of cutoff wall increases with an increase in hydraulic conductivity of backfill;the wall permeability has a limit due to low thickness and permeability of filter cake.

关 键 词：隔离墙 泥饼 渗透系数 压滤试验 渗透性 

分 类 号：TU94[建筑科学—建筑技术科学]