基础沉降对土路基上板式轨道动力性能影响分析

Analysis of the Dynamic Performance for Slab Track Settlement on Embankment

研究目的:无砟轨道的稳定性和耐久性由线下基础决定,而土路基上无砟轨道铺设成功的核心是不均匀沉降的控制,因此研究不均匀沉降对轮轨系统的动力影响对工程设计很有必要。研究方法:应用车辆-轨道耦合动力学理论,建立了土路基上车辆-板式轨道耦合动力学垂向模型,并编制相应的仿真计算程序。研究结果:选用不同沉降工况进行计算,得出轮轨系统的动力响应,以及不均匀沉降对轮轨系统的动力影响规律。研究结论:当车辆通过路基不均匀区段时,轮轨动力作用急剧增大,CA砂浆和路基面动应力明显增大,设计速度为250 km/h时,路基不均匀沉降建议控制在20 mm/20 m以内,困难路段不得超过30 mm/20 m,设计速度为300 km/h时,路基不均匀沉降建议应控制严格在20 mm/20 m以内。

Research purposes： The stability and enduring of slab track is controlled by the track foundation, and the asymmetrical settlement of embankment is the kernel factor, so it is very necessary to analyze the dynamic performance of wheel/rail system. Research methods： Based on the vehicle - track coupling dynamics theory, the vertical dynamics model of vehicle and track on the embankment had been set up, and the computer program is worked. Research results：The dynamics responses is obtained regards on different working condition, and the asymmetrical settlement influence law on the wheel/rail dynamic system is researched too. Research conclnsions：Analysis results indicate that the wheel/rail system dynamic interaction increased sharply when the vehicle passing over asymmetrical settlement, the dynamic stress of CA layer and embankment increased also. The asymmetrical settlement suggestion value should be limited to under 20 mm -30 mm/20 m with speed of 250 km/h, then the asymmetrical settlement suggestion value should be limited to under 20 mm/20 m with speed of 300 km/h.