严寒地区铁路路基冻融沉降数值模拟研究

Numerical Simulation Research of Railway Subgrade Settlement Caused by Freeze Thawing in Severe Cold Region

严寒地区铁路路基地处冻土区域,受温度等因素的影响易产生路基沉降变形。以严寒地区某铁路典型路基断面为研究对象,利用Midas有限元数值分析软件,在考虑季节性冻土结构性、冻融循环的基础上建立了冻融循环和列车动载耦合作用下的路基沉降预测模型。根据冻融循环期,将模型划分为若干个过程进行模拟分析,实现了季节性冻土体力学特征值的动态控制,为沉降变形计算提供依据。

If railway subgrade is located at frozen ground in severe cold region, it will be susceptible to temperatures and other negative factors, therefore the phenomenon of settlement deformation will occur at this kind of railway subgrade. In this paper, a typical subgrade cross-section of a certain railway in severe cold region was cited as a research object, and the finite-element numerical analysis software MIDAS was put into use. And then, considering both the constitutive property of the seasonal frozen soil and the freezing-thawing cycle, the paper established a prediction model of subgrade settlement under the coupling action of the freezing-thawing cycle and the dynamic train load. Further on, according to freezing-thawing cycle period, the model was divided into a number of processes so as to do numerical simulation analysis. As a result, the dynamic controlling over the mechanical characteristic values of seasonal frozen soil was achieved, which can provide basis for the calculation of settlement deformation.