水泥基材料渗透溶蚀有限元模拟方法  

Finite Element Modeling of Leakage Dissolution of Cement-based Materials

作　　者：贾攀 佘成学[1] JIA Pan;SHE Cheng-xue(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University, Wuhan430072, China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《长江科学院院报》2019年第5期108-115,共8页Journal of Changjiang River Scientific Research Institute

摘　　要：渗透溶蚀现象在国内外水利工程中大量存在,但对其研究的手段迄今为止还比较单一,为此,探讨采用有限元计算方法研究水泥基材料的渗透溶蚀现象。首先,基于离子在水泥基材料中的水动力弥散与对流作用机理,根据离子质量守恒定律、Fick第二定律、多孔介质渗流数学模型及达西定律建立三维渗透溶蚀过程中钙离子迁移数学模型;然后,结合钙离子迁移数学模型、固液平衡关系、孔隙率演化模型及扩散系数演化模型建立渗透溶蚀数学模型,并给出该模型的有限元计算方法;最后,通过对高水力梯度下的渗透溶蚀试验开展数值模拟,检验渗透溶蚀模型的正确性。计算结果与试验数据基本吻合,表明该方法能够用于模拟水泥基材料的渗透溶蚀过程。所做的研究工作为下一步水利工程中的渗透溶蚀模拟研究奠定了基础,对水利工程的结构安全性研究具有重要意义。Leakage dissolution which exists extensively in water conservancy projects in China and abroad has not been well revealed by numerical simulation. In view of this, with respect to leakage dissolution of cement-based materials, a research on finite element analysis method is conducted. Firstly, on the basis of the mechanism of hydrodynamic dispersion and convection of ions in cement-based materials, a three-dimensional mathematical model of Ca 2+ ion transport during leakage dissolution is developed according to the mass conservation law of ion, the Fick’s second law, mathematical model of flow in porous media and Darcy’s law. In subsequence, a three-dimensional mathematical model of leakage dissolution of cement-based materials is established based on the aforementioned Ca 2+ ion transportat model, the solid-liquid equilibrium curve, the porosity evolvement model and the diffusion coefficient evolvement model. Meanwhile, the finite element method for this model is given. Finally, the proposed model is validated by numerical simulation of leakage dissolution test under high hydraulic gradient. The simulated result is consistent with the experimental result, which demonstrates that the proposed model can be used to simulate the process of leakage dissolution of cement-based materials. The research lay a foundation for the modeling of leakage dissolution in water resources and hydropower engineering, and is of great significance to the study of structural safety of water resources and hydropower projects.

关 键 词：水泥基材料 渗透溶蚀 有限元模拟 钙离子迁移 水动力弥散 

分 类 号：O357.3[理学—流体力学] TV431[理学—力学]