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

Abstract: 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 Ca²⁺ 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 Ca²⁺ 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.

Key words: cement-based materials, leakage dissolution, finite element model, calcium ion transport, hydrodynamic dispersion