基于水动力学模型冻土冻胀数值模拟的改进  

Numerical Simulation Improvement of Frozen Soil's Frost Heave with Hydraulics Model

作　　者：商翔宇[1] 周国庆[1] 周金生[1] 

机构地区：[1]中国矿业大学建筑工程学院,江苏徐州221116

出　　处：《中国矿业大学学报》2006年第6期762-766,共5页Journal of China University of Mining & Technology

基　　金：国家重点基础研究发展规划(973)项目(2002CB412704);国家自然科学基金重点项目(50534040);国家自然科学基金项目(40471021);高等学校博士学科点专项科研基金项目(20040290502)

摘　　要：基于水动力学冻胀模型,对变化的边界条件下土体的冻胀量进行了大量计算．结果表明:由于水动力模型的控制方程中耦合源项在计算遣代步之内总是被不合理地估算,易于产生数值振荡以致整个计算难以收敛;利用土壤冻结特性曲线及计算出的负温和未冻水含量之间的特定关系,可以明确判断出迭代步计算所得耦合源项变化是偏大或偏小．据此,本文提出在迭代步内直接对含冰量变化进行合理修正的改进算法,并编制了基于有限体积法的自调节时间步长计算程序,该算法能够加速收敛、消除数值振荡,且与实测结果相当吻合,适用于复杂多变边界条件下土体的冻胀计算．Based on the hydraulics model, a large number of computations of frozen soil＇s frost heave with changeful boundary conditions were carried out. The results show that because the coupling source term in the model governing equation is estimated improperly, number surges unavoidably and the computation is difficult to converge. The magnitude of source term can be judged definitely to be overestimated or underestimated using the specific relation between minus temperature, unfrozen water content and soil-freezing characteristic curve. On the basis of this, an improved algorithm, which adjusted the ice content directly in each iterative step was proposed, and the corresponding program with self-adjust time step and finite volume method is programmed. This algorithm can not only accelerate the convergent speed and remove the numerical oscillation, but also apply to many kinds of changeful boundary conditions.

关 键 词：冻土 冻胀 数值模拟 算法改进 

分 类 号：TU445[建筑科学—岩土工程]