在季节冻土区，尤其是在深季节冻土区，冻害对铁路路基寿命有着严重的影响，因而抑制路基冻胀是季节冻土区路基设计的基本原则。本文对铺设保温层的效果，运用土壤冻结条件下水热耦合输移的基本方程和数值方法，模拟分析在不同的埋深、宽度、厚度和施工季节条件下，铺设XPS保温材料板对路基下季节冻土最大季节冻结深度在以后50年内随时间的变化。在数值模拟的基础上，提出在季节冻土区铁路路基工程中埋设保温层的合理深度、宽度及施工季节；总结分析保温板厚度和路基填土高度之间的关系。

Frost heave has caused serious distresses to railway roadbeds in seasonal, especially deep seasonal, frozen regions. Therefore, frost heave prevention is the basic principle of roadbed design in seasonal frozen regions for many years. Frost heave has caused serious distresses to railway roadbeds in seasonal, especially deep seasonal, frozen regions. Therefore, frost heave prevention is the basic principle of roadbed design in seasonal frozen regions. The coupled heatfluid transport equation and twodimensional finite element method were employed to simulate the maximum frozen depth in the coming 50 years under the roadbed with XPS insulation board in the conditions of different depth, width, thickness and construction season for studying the insulation effect. Based on numerical simulation, appropriate depth, width and construction season were proposed for insulation design and the relationship between the thickness of insulation board and the height of roadbed was analysed as well.

中科院知识创新工程重要方向性项目（KZCX2YWQ0304）；中科院知识创新工程重要方向项目（KZCX3SW351）；国家高技术研究发展计划（863计划）项目（2008AA11Z103）；国家自然科学基金重点资助项目（40730736）