低渗透性污染场地高压旋喷修复药剂迁移特性数值模拟分析  

Numerical simulation of migration characteristics of high-pressure rotary jet remediation agents in low-permeability polluted sites

作　　者：王蓉 翟新乐 吕玺琳[4] WANG Rong;ZHAI Xinle;LÜXilin(SGIDI Engineering Consulting(Group)Co.,Ltd.,Shanghai 200093,China;Shanghai Engineering Research Center of Geo-Environment,Shanghai 200093,China;Faculty of Geosciences and Engineering,Southwest Jiaotong University,Chengdu 611756,Sichuan,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]上海勘察设计研究院(集团)股份有限公司,上海200093 [2]上海环境岩土工程技术研究中心,上海200093 [3]西南交通大学地球科学与工程学院,四川成都611756 [4]同济大学地下建筑与工程系,上海200092

出　　处：《地基处理》2024年第6期580-588,共9页Journal of Ground Improvement

基　　金：国家自然科学青年基金项目(42202317);上海市科委科技支撑计划项目(13231202300)。

摘　　要：近年来,高压旋喷注药修复技术在低渗透性污染场地中得到广泛应用,药剂注入后在孔周土体中的迁移规律值得深入探讨。考虑分子扩散、机械弥散、对流、颗粒迁移等条件,对高压旋喷注药孔周围地层的药剂时空分布进行有限元数值模拟。模拟结果表明:高压旋喷产生的高速流动溶液引起土体内部细小颗粒迁移,导致渗透系数增大并影响药剂弥散和对流;随着注药压力升高,土体渗透系数增大,药剂迁移位置更远,场地修复区域面积扩大;在高注药压力条件下,渗透系数变化较小,修复面积无明显变化。因此,提高注药压力有助于扩大低渗透性场地的修复面积,但过高压力将使功效降低。研究成果可为低渗透性场地的高压旋喷注药修复设计提供理论支撑。High-pressure rotary jet technology is increasingly applied in the in-situ remediation of low-permeability contaminated site recently.The migration patterns of remediation agents in the soil surrounding the borehole after injection worth further investigation.In this study,the spatio-temporal distributions of agents around the borehole were simulated using finite element method considering the coupled effects among molecular diffusion,mechanical dispersion,convection and fines migration.The results show that high-speed flow fluid leads to fines migration in soil and higher permeability,which affects the convection-diffusion of agents.With the increasing of agent-injection pressure,the permeability grows significantly,resulting in bigger remediation area.Under high injection pressure conditions,the change in permeability coefficient is relatively small,and the remediation area does not significantly increase.Therefore,increasing injection pressure can help expand the remediation area in low-permeability sites,but excessive pressure may reduce the overall efficiency.The findings provide theoretical basis for the design of high-pressure rotary jet remediation in low-permeability sites.

关 键 词：污染场地 低渗透性 高压旋喷 颗粒迁移 对流-扩散 数值模拟 

分 类 号：TU47[建筑科学—结构工程]