季冻区浅挖路基水热耦合分析

Analysis of Water-Heat Coupling of Shallow Excavated Subgrade in Seasonal Freezing Area

针对省道224线二道沟兵站109岔口至治多段二级公路水热变化及是否采取工程措施来保证路基稳定的问题,借助COMSOL Multiphysics对典型季节性冻土区浅挖路基、铺设土工格栅及保温板的路基水热力场进行数值模拟,分析路基冻结深度的变化规律和路基冻胀规律,为高寒地区公路路基冻害防治措施设计提供参考。研究表明:浅挖路基路中冻胀量大于路肩处冻胀量,且最大冻深出现时间要比最大冻胀量出现时间晚一个月;路基中铺设土工格栅和保温板都能减小路基冻胀,但保温板效果更加显著,且铺设土工格栅对于路基最大冻结深度不会产生影响,而铺设保温板则会显著减小路基冻结深度。

According to the water and heat change of the secondary road from the 109 fork of Erdaogou Military Station of Provincial Highway 224 to the Zhiduo section,it is necessary to decide whether to take engineering measures to ensure the stability of the roadbed.With the help of COMSOL multiphysics,the hydrothermal field of shallow excavation subgrade,laying geogrid and insulation board in typical seasonal frozen soil area is numerically simulated.The change law of roadbed freezing depth and roadbed frost heaving law are analyzed to provide a reference for the design of roadbed freezing damage prevention measures in high-cold areas.The results show that:the frost heaving of shallow excavation subgrade is greater than that of the shoulder,and the maximum frost depth appears one month later than the maximum frost heaving;the laying of geogrid and insulation board in the roadbed can reduce the frost heave of the roadbed,but the effect of the insulation board is more significant,and the laying of the geogrid will not affect the maximum freezing depth of the roadbed,while laying the insulation board will significantly reduce the freezing depth of the roadbed.