高速铁路路堑基床变形原因分析及治理

Cause Analysis and Treatment of Deformation of Cutting Subgrade Bed in High Speed Railway

研究目的:高速铁路对线路的沉降控制和平顺性要求极高,路基基床的变形量是影响高速铁路安全运行的关键性指标之一,同时也是协调轨面变形和判断扣件系统安全储备量的因素之一。本文以某高速铁路路堑基床变形为例,综合考虑各种影响因素,分析基床变形的可能原因,旨在探索适宜的治理方式。研究结论:(1)通过对基床结构的长期冻胀观测与变形监测,综合考虑冻胀变形、混凝土温度翘曲、卸荷回弹、基底地层膨胀变形等可能因素,确定导致基床变形的原因是基底基岩的膨胀变形;(2)针对问题发生的原因,联合采用砂砾垫层、三七灰土垫层、两布一膜和混凝土预制块的有机组合结构,配合纵向排水沟和侧沟混凝土包裹层,以增强基底排水能力和地面径流的方式治理膨胀岩土路基病害,实践证明该措施治理效果良好;(3)本研究成果可为治理高速铁路路堑基床变形积累经验,并可为相关工程的设计与施工提供参考依据。

Research purposes:The high speed railway has extremely high requirements for settlement control and smoothness of the line.The deformation of the subgrade bed is one of the key indicators affecting the safe operation of the high speed railway.It is also one of factors for coordinating the deformation of the rail surface and judging the safety reserve of the fastener system.This paper takes the deformation of a high speed railway cutting subgrade bed as an example,comprehensively considers various influencing factors,and analyzes the possible causes of bed deformation,to explore appropriate treatment methods.Research conclusions:(1)According to the long-term frost heave monitoring and deformation monitoring of the subgrade bed structure,considering the possible factors such as frost heave deformation,concrete temperature warping,unloading rebound,swelling deformation,the deformation of the subgrade bed caused by the swelling deformation of the bedrock is finally determined.(2)For the cause of the problem,the sand-gravel cushion,three-to-seven lime cushion,dual textiles and one membrane,and concrete precast block are used,vertical drainage ditch and side ditch concrete wrap are combined with to enhance drainage capacity and surface runoff,which can manage the subgrade defect of the swelling rock and soil.Practice has proved that this measure has a good treatment effect.(3)The research results have accumulated successful experience in the treatment of cutting subgrade bed in high speed railway,and can provide reference for the design and construction of related projects.