季节冻土区基床改性填料与保温护坡对路基温度场的影响分析

高速铁路对轨道平顺性具有非常高的要求，在季节冻土区建设的铁路面临着路基冻胀问题，由路基冻胀引起的轨道变形严重影响了高速铁路运行的安全性与舒适性.通过对比其他学者关于路基冻胀的处理与防治方法，提出了采用水泥稳定级配碎石代替普通级配碎石作为基床表层填料，同时在路基边坡铺设保温护坡的方法来防治路基冻胀.根据哈大客运专线季节冻土区的地质及气候条件，采用有限元数值仿真方法分析路基基床表层采用水泥稳定级配碎石和在路基边坡加设保温护坡后对路基温度场的影响.并将分析结果与哈大客运专线的现场实测结果进行了对比，验证了有限元数值仿真结果的可靠性，分析结果表明：在基床表层换填水泥稳定级配碎石，同时在路基边坡铺设3.0 m高、2.5 m宽的保温护坡后可以有效缓解路基的冻胀，与无任何保温措施的普通路基相比，路基中心处的最大冻结深度减小了0.5 m，路肩处的最大冻结深度减小了1.1 m.

Analysis of the influence of bedding modified filler and insulation slope protection on temperature field of roadbed in seasonally frozen soil regions

High speed railway requires a high level of ride comfort,the construction of railway facing the prob-lem of subgrade frost heaving in the seasonally frozen soil regions.The deformation of track caused by subgrade frost heaving has seriously affected the safety and comfort of high-speed railway.In this paper,a method for the prevention and treatment of subgrade frost heaving is presented,which uses the cement stabilized grading crushed stones instead of ordinary graded crushed stones as filler in surface layer of subgrade bed and lays insulation slope protection in roadbed side slope,by comparing with other scholars on the subgrade frost heaving prevention and treatment methods.According to the geologic and climate conditions of the seasonally frozen soil regions along the Harbin-Qiqihar Dedicated Passenger Line,using the finite element numerical simulation method to analyze the influence on temperature field of roadbed after laying cement stabilized grading crushed stones in the surface layer of subgrade and laying insulation slope protection in the subgrade slope.And the reliability of finite element numerical simulation results is verified by comparing with the field measurement results of Harbin-Dalian Dedica-ted Passenger Line.The numerical results show as follows:Replacement of cement stabilized grading crushed stones in the surface layer of subgrade,while laying 3 m high,2.5 m wide insulation slope protection in the subgrade slope can effectively alleviate the frost heaving,compared with the ordinary subgrade,the maximum freezing depth at the center of subgrade is reduced by 0.5 m,and the maximum freezing depth at the shoulder of subgrade is reduced by 1.1 m.