兰新铁路路基温度场和水分场耦合数值分析

摘要

The mechanism of freeze injury of Lanxin Railway is analyzed and the main influence factors of soil,water and temperature are expounded. According to the influence of temperature change on the water migration,the coupling model of the temperature and moisture field is established based on Geostudio software. The hydrothermal coupling of the embankment of Lanxin Railway is simulated and analyzed,and the distribution solution of temperature and moisture field of freeze embankment in a freeze-thaw cycle is obtained. The simulation and measured data indicate that the moisture redistributes in condition of temperature gradient,and this is the major cause of the subgrade freeze injury. Furthermore,it is proposed that the prevention of moisture migration is the principal measure to solve the frost heave in subgrade combining with the practical situation of Lanxing Railway.%主要分析了兰新铁路冻害机理，阐述了铁路冻害主要影响因素是土质、水分和温度.考虑温度变化对水分迁移机理的作用，通过Geostudio软件建立温度场和水分场耦合模型，对兰新铁路路基进行水热耦合模拟和数值分析，得出一个冻融循环周期内冻土路基温度场和水分场的分布解.通过计算与实测数据可以得出在温度梯度条件下，水分发生了重分布现象，且是造成路基冻害的主要原因.同时结合兰新铁路的实际情况，提出了阻止水分迁移是解决路基冻胀的主要措施.