不同离散化方法在正冻土水热耦合模型中的应用  

DIFFERENT DISCRETIZATION METHOD USING IN COUPLED WATER AND HEAT TRANSPORT MODE FOR SOIL UNDER FREEZING CONDITIONS

作　　者：毛卫南[1] 刘建坤[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《工程力学》2013年第10期128-132,共5页Engineering Mechanics

基　　金：国家自然科学基金项目(41171064);国家基础研究计划973项目(2012CB026104);北京交大基础科研项目(2011YJS252)

摘　　要：为了研究土体冻结过程中温度传导与水分迁移的变化,在不饱和土理查德斯方程的基础上考虑相变作用建立了一维土体冻结过程的水热耦合模型。分别应用有限差分与有限元方法对模型进行离散化,得到两种方法各自的数值计算程序。同时对土体室内单向冻结实验进行模拟,将两种数值方法得到的土体冻结深度、冻结速率与温度变化分别与实验结果进行对比。结果表明:对于一维冻结问题,有限差分模拟更接近实验结果,有限元模拟具有更高的计算稳定性。A coupled water and heat transport mode is established, based on the Richards equation to study the water flow and heat transport in soil during a freezing process. Both the finite difference and finite element method are used in the discretization respectively. Two different computer programs are written and employed to simulate an indoor unidirectional frozen test. The freezing depth, freezing rate and temperature variation are compared among the real test, the finite difference calculation model simulation and the finite element calculation model simulation. The result shows that： the finite difference method has a better performance in freezing depth simulation and the finite element method has a better performance in one-dimensional freezing stability simulation.

关 键 词：正冻土 水热耦合 有限差分 有限元 冻结实验模拟 

分 类 号：TU43[建筑科学—岩土工程]