大跨系杆拱桥上道岔纵向耦合及列车走行性分析

摘要

To meet the engineering requirements of laying welded turnouts on tied arch bridges,the longitudinal and lateral-vertical coupling vibration models were built based on the interaction principles of turnout-bridge and coupling dynamics of vehicle-turnout-bridge.Taking an example of a 205 m continuous beam bridge on a new passenger dedicated line,three bridge types and nine kinds of layouts in total were involved to analyze the coupling characteristics of the turnout-bridge system and vehicle running performance.The turnout-bridge longitudinal interaction shows that the temperature span has a great influence on the longitudinal deformation of the welded turnouts.And the disciplines of rail additional expansion and contraction forces of different bridge types are the same,but the force values are different.For the Neilson rigid-frame arch bridge plans,the rail additional expansion and contraction forces,relative displacements between the tip of switch rail and stock rail,relative displacements between the tip of nose rail and stock rail,and rail break are all minimum.However,for the large-span continuous beam-arch bridges,the corresponding values are maximum.As to laying welded turnouts on tied arch bridges,the relative displacement between the stock rail at switch machine and bridge is an important factor in selecting the optimal plan.The vehicle running performance analysis shows that the vertical dynamic displacement of Neilson rigid-frame arch bridge is relatively large,and the rate of wheel load reduction exceeds the limit in an instant.In contrast,for the small-span continuous beam bridge,the dynamic displacement is only 1.33 mm,vehicles have a good running performance in safety and comfort,and the maximum lateral acceleration of the car body is only O.035g.%针对大跨系杆拱桥上铺设无缝道岔的工程需求,根据岔-桥相互作用原理和列车-道岔-桥梁耦合动力学原理,分别建立了纵向耦合与垂横向耦合振动仿真分析模型.以某新建客专205 m连续梁桥为例,结合3种桥型共9种布置方案,对其岔桥耦合特性和列车走行性进行综合分析研究,结果表明:温度跨度对此类桥上无缝道岔纵向受力变形影响较大,不同桥跨形式的伸缩附加力规律相同,大小不同,其中尼尔森刚架拱方案伸缩附加力、道岔尖轨尖端和心轨尖端相对基本轨的位移、钢轨断缝的最值最小,大跨连续梁拱桥最大;就大跨系杆拱桥上无缝道岔而言,转辙机处基本轨与桥梁相对位移是影响桥垮选型的重要因素;尼尔森拱桥因主跨跨度较大导致桥梁动位移相对较大,存在轮重减载率瞬时超限的问题,而小跨连续梁拱桥梁动位移仅1.33 mm,列车走行安全性和舒适性表现良好,车体横向振动加速度最大仅0.035g.