普速铁路涵洞覆土厚度不足地段轨道减振措施研究

既有线经提速改造后,因标准提高,出现涵洞地段原有的覆土厚度不满足规范要求,列车通过时引起较大振动,必须采取相应的轨道减振措施。调研常用的轨道减振方法,结合既有宁启线200 km/h提速工程实例,运用车辆-轨道耦合动力学理论,对不同减振方案下车辆、轨道、路基的动力学指标进行仿真计算。计算结果表明:不减振措施方案,不能满足时速200 km线路要求;减振方案各项计算结果均满足相关规定要求,能满足时速200 km线路要求。根据仿真计算结果,综合分析施工方便性、整治后的工后沉降以及综合经济性指标后,对200 km/h提速工程涵洞覆土厚度不足地段得出以下结论:0.65 m≤覆土厚度h≤1.2 m地段,采用弹性长轨枕方案,覆土厚度h0.65 m地段,采取线路纵断面调整措施将覆土厚度调整至0.65 m以上。

The Study on Track Vibration Reduction in the Section of Insufficient Thickness of Covering on Conventional Railway Culvert

The thickness of covering on culvert can not satisfy the specifications due to the improved standard after the exiting railway is upgraded for speed-up and the vibration of wheel/rail system is increased when trains go through those sections. Thus,the vibration reducing measures should be studied.This paper investigates the normal vibration reduction measures in sections with insufficient thickness of covering. In view of the 200 km/h speeding up engineering project of Ning Qi,and the dynamic model of wheel/rail system is established and then simulation calculation of dynamic indicators based on different reinforcement measures is conducted. The calculation results show that the various power indicators don't conform to the specifications without vibration reducing measures and the power indicators conform to 200 km/h speeding up standard with vibration reducing measures. Based on the results of simulating calculation,comprehensive analysis and construction convenience,the post-construction settlement and the economic indicators,this paper finally draws the following conclusions: for sections with 0. 65 m ≤thickness of covering soil h≤1. 2 m,elastic long sleeper is employed; and for sections with thickness of covering soil h< 0. 65 m,the longitudinal cross section is adjusted to increase the thickness of covering soil h over 0. 65 m.