渗流-化学溶解耦合作用下岩石单裂隙渗透特性研究  

Study of permeability in single fracture under effects of coupled fluid flow and chemical dissolution

作　　者：速宝玉[1] 张文捷[1,2] 盛金昌[1] 许孝臣 詹美礼[1] 刘继山[4] 

机构地区：[1]河海大学水利水电工程学院,南京210098 [2]江西省水利厅,南昌330009 [3]浙江广川工程咨询公司,杭州310000 [4]西澳大利亚大学机械与化学工程系

出　　处：《岩土力学》2010年第11期3361-3366,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No50779012);教育部留学回国人员科研启动基金(2008)

摘　　要：为揭示在渗流-化学溶解耦合作用下单裂隙渗透特性的变化规律,建立了描述二维渗流-化学溶解耦合作用的偏微分方程组,并利用COMSOL Multiphysics软件成功地求解该方程组。首先,模拟了文献[1]中的盐岩渗流-溶解耦合渗流试验结果,数值模拟结果与试验结果较为吻合,验证了数学模型的正确性和有效性。然后,利用分形理论生成了一个粗糙的裂隙面数字模型,着重分析了二维石灰岩粗糙裂隙面在水流、矿物溶解和输运过程中其渗透特性的变化规律。数值分析显示,(1)溶质浓度对裂隙面的溶解具有非常重要的作用,从而水流进口端的溶解厚度比出口端大得多。(2)裂隙的整体渗透性在初始时刻增加较慢,随着裂隙开度的增大和贯通,溶解速度会逐渐增大,是一个加速的过程。A two-dimensional numerical model of coupled fluid flow and chemical dissolution processes in single fracture is presented in order to understand permeability changes of single rock fracture in the coupled fluid flow and mineral chemical dissolution processes.The numerical model is solved by using a COMSOL Multiphysics-based simulator,which is the first engineering tool that performs partial differential equation-based multiphysics modeling in an interactive environment.The model is validated through comparing our numerical results with the known experimental measurements in salt rock reported by the reference [1],which shows our model is credible.A rough fracture is generated numerically by using fractal theory and used in the simulation of coupled fluid flow and mineral chemical dissolution processes of a rough fracture in limestone.The simulated results indicate that：（1） The solute concentration plays an important role on the dissolution process;this causes that the dissolved thickness at inlet is bigger than that at outlet.（2） The permeability of fracture increases exponentially with time during the dissolution process.

关 键 词：岩石裂隙 渗流-化学溶解耦合过程 数值模拟 分形理论 

分 类 号：TU452[建筑科学—岩土工程]