隧道内新型活动承轨台框架板式无砟轨道力学检算

线下基础上拱是隧道内无砟轨道线路常见病害之一,基础变形过大会破坏无砟轨道结构整体性,危害列车安全平稳运行。为快速适应隧道内轨下基础形变,结合弹性支承块式无砟轨道与框架板式无砟轨道优点,提出具有立体式调节系统的新型活动承轨台框架板式无砟轨道。基于有限元法分析不同结构参数对轨道结构力学的影响,验证大调整量下CA砂浆灌浆袋、承轨台高度的安全性能,根据计算结果,建议橡胶套靴下部刚度取450 kN/mm,CA砂浆弹性模量取250~300 MPa。通过动力学计算验证160、200、250 km/h速度下列车运行安全平稳性,表明列车横垂向振动加速度、轮轨横向力、轮重减载率、脱轨系数标均低于规范限值。研究成果对隧道内大调整量无砟轨道改良提供新参考方向。

Mechanical Check Computation of a New Type of Frame Slab Ballastless Track with Movable Rail Bearing Platform in Tunnel

The substructure upheaval is one of the common defects of the ballastless track in tunnels.Excessive substructure deformation will destroy the structural integrity of the ballastless track and endanger the safe and stable operation of trains.In order to quickly adapt to the substructure deformation in tunnels,a new type of frame slab ballastless track with movable rail bearing platform and a three-dimensional adjustment system is put forward based on the advantages of the low vibration track and frame slab ballastless track.On the basis of the finite element method,the influence of different structural parameters on track structure mechanics is analyzed,and the safety performance of CA mortar grouting bag and the height of rail bearing platform under extensive adjustment is verified.In line with the calculation results,it is suggested that the lower stiffness of rubber boots should be taken as 450 kN/mm,and the elastic modulus of CA mortar should be taken as 250~300 MPa.Through dynamic calculation,the safety and riding comfort of train operation at 160,200 and 250 km/h is verified,indicating that the lateral and vertical vibration acceleration,wheel-rail lateral force,rate of wheel load reduction and derailment coefficient of trains are all lower than the specified limits.The research results provide a new reference for improving the ballastless track with extensive adjustment in tunnels.