地下水对压实高庙子膨润土冲蚀作用研究  

Erosion of compacted Gaomiaozi bentonite by groundwater flow

作　　者：陈宝[1] 田昌春 郭家兴[2] 陈建琴[1] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]铁道第三勘察设计院集团有限公司,天津300142

出　　处：《岩土力学》2016年第11期3224-3230,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.41372270)~~

摘　　要：采用膨胀渗透仪和浊度仪,通过检测冲蚀循环溶液浊度和膨润土试样膨胀力的变化,获得了冲蚀液对高庙子(GMZ)膨润土的冲蚀规律,对比分析了膨润土干密度、冲蚀液pH值、冲蚀液渗流方向、围岩裂隙条数、溶液类型和浓度等因素对膨润土冲蚀的影响规律。研究表明:膨润土的膨胀力在冲蚀开始的几天内迅速增长,随后达到稳定,膨润土干密度越大,地下水对膨润土的冲蚀作用越弱;冲蚀液pH值对膨润土的冲蚀作用影响很大,碱性较强的地下水对膨润土的冲蚀作用较弱,而碱性较弱地下水的冲蚀作用则明显;地下水径向渗流时对膨润土的冲蚀作用大于纵向渗流情况,围岩裂隙增多后,地下水对膨润土的冲蚀作用加强;随着冲蚀液中NaCl浓度的增加,冲蚀液对膨润土的冲蚀作用先增强后减弱,冲蚀液中CaCl_2的浓度对膨润土的冲蚀影响规律与NaCl浓度对膨润土的冲蚀影响规律相似,但CaCl_2浓度的变化对膨润土的冲蚀影响不明显。The aim of the paper is to investigate the effect of groundwater flow on Gaomiaozi bentonite（GMZ）. The expansion-permeameter and turbidity meter are used to measure the turbidity of erosion liquid and the expansibility of bentonite samples. The influence of such factors as the dry density of bentonite, p H value and flow direction of erosion solution, type concentration of solution, and crack amount of surrounding rocks is analyzed. It can be concluded that： the expansibility of bentonite increases dramatically during the first several days and remains stable then; the higher dry density of the bentonite, the weaker erosion presents on bentonite; p H value has a great influence on the erosion of bentonite, and the erosion is weaker under a higher alkaline conditions and vice versa; radial seepage of water flow has a greater effect on the erosion of bentonite than vertical seepage; and the erosion of bentonite becomes more intensive if the crack amount increases; the erosion of bentonite firstly increases and then decreases as Na Cl concentration in erosion solution increases; the influence of Ca Cl2 concentration on bentonite is similar to that of Na Cl, but the effect of Ca Cl2 is less significant.

关 键 词：膨润土 地下水 冲蚀 浊度 膨胀力 

分 类 号：TU411[建筑科学—岩土工程]