客运专线桥上无缝道岔空间力学特性的研究

Study on the Spatial Mechanical Characteristics of Welded Turnout on the Bridges for Passenger Dedicated Lines

为解决哈大客运专线红嘴河特大桥桥上无缝道岔受力和变形问题,根据道岔、桥梁结构和布置形式,建立桥上无缝道岔空间耦合模型,从温度荷载、竖向荷载、钢轨横向变形等方面对其空间力学特性进行分析。结果表明:温度荷载下钢轨的伸缩附加力最大值位于梁体活动支座端,受固定支座端至活动支座端距离影响较大;尖轨、心轨尖端相对于基本轨、翼轨的位移较小,处于外锁闭机构允许的伸缩量范围之内;连续梁半联满布荷载时,钢轨纵向位移、挠曲附加力及桥梁竖向挠度最大;单线直向满布荷载时,桥梁横向挠度、扭转最大;温度荷载对钢轨横向变形的影响较小,减载率、脱轨系数变化不大。但由于客运专线标准高、道岔与桥梁结构复杂等因素,对钢轨横向变形的影响不容忽视,建议设计客运专线桥上无缝道岔时考虑其空间力学特性。

In order to solve the problems of stress and deformation of welded turnout on Hongzuihe super large bridge for passenger dedicated lines, a spatial coupling model of welded turnout on bridge is set up according to the structures and arrangement forms of turnout and bridge. The spatial mechanical characteristics induced by temperature load, vertical load, transverse deformation of rail, etc. are analyzed. The resuits show that the maximum value of the rail additional expansion and contraction force appears at the movable end of girder body under temperature load, and it is influenced significantly by the distance between the fixed and movable bearings. The relative displacements between the switch rail and the nose rail, point of nose rail and wing rail are smaller, and within the expansion range of the external locking device. When applying load fully on the half of continuous beam, rail longitudinal displacement, additional deflection force and bridge vertical deflection reach maximum. When applying load fully on the straight single-track line of the beam, bridge transverse deflection and torsion value reach maximum. Rail transverse deformation induced by temperature load is relatively small, and has little influence on the reduction rate of wheel load and derailment coefficient. Because of all sorts of factors such as high standard of passenger dedicated line and complicated structure of turnout and bridge, the influence of rail transverse deformation should not be ignored. It is suggested that the spatial mechanical characteristics should be considered in designing the welded turnout on bridge for passenger dedicated lines.