研究目的: 为了分析温度荷载、列车荷载作用下长大坡道桥上板式无砟轨道纵向力学特性,为大坡道上无砟轨道设计提供理论依据。
研究结论: 本文根据“线 - 桥 - 墩”纵向相互作用机理,运用有限元方法,建立了“钢轨 - 轨道板 - 桥梁 -墩台”纵向一体化计算模型,并编制了相应的通用程序。利用所编制的程序,计算了客运专线上常见的 5 ×32 m 简支梁和连续梁纵向力学特性,并对扣件纵向阻力、凸台树脂弹性模量、板底摩擦系数以及温度荷载的大小进行了参数影响分析。计算分析结果表明: ( 1) 对于大坡道板式轨道,应将钢轨和轨道板、轨道板和桥梁的纵向相对位移限制在 0. 2 mm 以内,对应的凸台树脂的弹性模量应大于 120 MPa。( 2) 大坡道桥上需增加考虑制动作用和活载的纵向分力进行凸台的承载能力检算。同时应加强凸台结构以及凸台、填充树脂和轨道板的粘结强度。
Research purposes: The analysis of the longitudinal mechanics behaviour of the ballastless slab track on long grade bridge under the effects of the temperature load and train load was made for providing the theoretical basis for the design of the long grade ballastless track.
Research conclusions: The finite element method was used to set up a longitudinal integration calculation model of rail -track slab - bridge - pier based on the longitudinal interaction mechanism of line - bridge - pier,and the corresponding general calculation program was compiled. With the program,the longitudinal stresses behaviour of the commonly - used 5 × 32 m simply - supported beam bridge and continuous bridge of passenger dedicated line were calculated,and the analyses of the parameter influence of the fastener longitudinal resistance,resin elastic modulus of the convex plate, friction coefficient of the bottom track slab and the temperature load value were made. The calculation results show ( 1) For the long grade slab track,the longitudinal relative displacements of rail - slab and slab - bridge should be limited within the range of 0. 2 mm and the corresponding resin elastic modulus of convex plate should be larger than 120 MPa. ( 2) The brake effect and longitudinal component force of live load should be applied to the bridge on long grade to make the computational check of convex plate. At the same time,the convex plate structure should be strengthened and the bonding strengths of convex plate,filling resin and track slab should be enhanced.