冻土墙墙体时空扩展的材料非线性有限元分析

Nonlinear Material FEM Analysis of Space-time Expending of Frozen Wall

用于人工冻土墙形成过程相关计算的Sanger -Sayles经验公式虽然有便于工程使用的优点 ,但由于该公式是Fourier热传导方程在轴对称条件下的求解结果 ,与实际工程条件相差甚远。对结构形成过程中的能量计算采用了不合理的温度分布假设 ,计算结果不能令人满意。而且 ,该公式只能处理单值的热物理参数问题 ,因此 ,这些都限制了公式的应用。运用有限元分析程序 ,完成了对热物理参数非线性变化的土体材料的人工冻结过程的计算分析 ,模拟了冻结结构时空扩展过程 ,深入研究了土体内的温度分布以及能量消耗等具有实际工程意义的问题 ,在此基础上推广出的关于冻结过程的能量消耗计算的一般形式 。

In spite of the properties of its convenience to engineering application, Sanger-Sayles formula, a method frequently used in thermal calculation of artificial frozen wall expending, is the solution of Fourier's thermal equation with the axisymmetric boundary conditions far from the practical engineering. The unreasonable temperature distribution hypothesis adopted into the energy calculation made the result dissatisfied. Furthermore, the formula can only deal with the problems with single value of thermal physical parameters. The all above-mentioned have limited its application. Applying FEM, this paper accomplished the computational analysis of the process of artificially freezing the soil with nonlinear changing thermal physical parameters, simulated the frozen wall expending, thoroughly studied the problems of practical engineering meanings such as inner soil temperature distribution and energy exhaust, the general form concerning the energy exhaust during freezing contains the significant sense to engineering design of the artificial frozen wall.