羟丙甲纤维素对铜污染土-膨润土屏障工程特性的改良效果  

Improvement effect of hydroxypropyl methylcellulose on engineering characteristics of soil-bentonite barrier polluted by copper

作　　者：葛均健 崔琦 陈兵[1] 刘宁 GE Junjian;CUI Qi;CHEN Bing;LIU Ning(State Key Laboratory of Ocean Engineering,Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure,Shanghai Jiao Tong University,Shanghai 200240,P.R.China;Shanghai Shengyi Environmental Technology Co.,Ltd.,Shanghai 200240,P.R.China)

机构地区：[1]上海交通大学海洋工程国家重点实验室,上海市公共建筑和基础设施数字化运维重点实验室,上海200240 [2]上海胜义环境科技有限公司,上海200240

出　　处：《土木与环境工程学报（中英文）》2023年第6期165-172,共8页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51972209)。

摘　　要：土-膨润土屏障作为污染场地隔离保护的重要手段之一,现已在工程中广泛应用。在土-膨润土屏障中加入羟丙甲纤维素(HPMC),能有效弥补因在重金属污染环境中受侵蚀而导致防渗性能衰减的问题。通过自由膨胀试验、扫描电镜试验、渗透试验、一维压缩试验与直剪试验,研究铜离子对膨润土膨胀性能的破坏作用及HPMC的改良作用机理,并研究高铜离子浓度(50 mmol/L)环境下不同掺量的HPMC对屏障材料防渗性能的改良效果及其对力学性能的影响规律。结果表明:HPMC可减小铜污染膨润土的团聚,并保持膨润土的连续结构;随着HPMC掺量的增加,屏障材料受破坏程度变低,防渗性能更好,其渗透系数k<10-10 m/s;材料压缩性变大,但抗剪强度略有降低。Soil-bentonite barrier is one of the most important means to isolate contaminated sites,which has been widely used in engineering practice.Adding hydroxypropyl methylcellulose(HPMC)to the soil-bentonite barrier can effectively make up for the attenuation of its anti-seepage performance in heavy metal environment.A series of experiments including free expansion,scanning electron microscope,permeability,one-dimensional compression and direct shear strength for the destruction of bentonite structure by copper ion,the improvement mechanism of HPMC and the barrier mixing HPMC with different ratios are conducted under high ion concentration(50 mmol/L)environment.The results show that HPMC can reduce the agglomeration of copper contaminated bentonite,keep the continuous structure of bentonite and as HPMC mixing ratio increases,the damage degree of barrier gets lower and the anti-seepage performance becomes better.The mechanical properties of barrier such as the compressibility increases,but shear strength decreases slightly with higher HPMC mixing ratio.

关 键 词：羟丙甲纤维素 膨润土 渗透 压缩 剪切强度 

分 类 号：TU443[建筑科学—岩土工程]