高原冻土区既有线路基病害防治技术

Prevention and treatment technologies of subgrade's defects on existing railway in plateau frozen soil region

针对青海省柴达尔支线铁路扩能改造工程设计,对既有路基进行全面现场勘察,分析病害的发育性状及分布规律,并从帮宽路基病害机理出发,提出了"防冻为主,综合治理"的设计原则。从换填既有基床填料、修筑保温护道、铺设土工格栅、整治基床翻浆冒泥及下沉外挤、改造和完善路基排水系统等方面总结出了一套适合高原冻土区路基病害的综合防治技术。经改造后路基沉降远小于允许值,在保护冻土的同时也保护了生态环境,为高原冻土区既有线的扩能改造工程积累了经验。

According to Chai Dahl branch railway expansion renovation project design in Qinghai province,this paper made a comprehensive field investigation of the existing subgrade,analyzed the developmental character and distribution law of defects,presented the design principle of “congealment prevention first and comprehensive management”from the mechanism of subgrade defects widening,and summarized a set of comprehensive techniques for the subgrade defects prevention and control in plateau permafrost region from replacing existing subgrade filler, building insulation berms,laying geogrid,treating subgrade frost boiling and sinking extrusion,reforming and improving the subgrade drainage system. After the reconstruction,the settlement value of subgrade is far less than the allowable value and ecological environment could also been protected at the same time of permafrost protection, which has accumulated the experience for the expansion and reconstruction project of existing railway in plateau permafrost region.