城际轨道交通桥梁梁端扣件节点间距研究

Research on the Node Space of Fastening at End of Bridge Beam for Intercity Rail Transit

研究目的:建设城际轨道交通线,为节省土地全线基本以桥梁为主;为减少道砟粉尘影响环境,采用无砟轨道结构。当桥上采用CRTS I型板式无砟轨道时,受线路小曲线半径的影响,梁缝处扣件节点间距不能满足规范650 mm的要求,影响桥上无砟轨道设计方案的实施。通过研究,提出可行的设计方案,解决梁端扣件节点间距存在的问题。研究结论:通过分析研究钢轨挠度、梁缝处断轨时钢轨弹性挤开量、板端混凝土剪切应力的设计参数、设计工况及评判指标,对梁端扣件节点间距处的轨道结构进行了受力分析,得出梁端扣件节点间距突破规范规定,按725 mm控制的设计方案可行的结论,解决了桥上采用无砟轨道时梁端扣件节点间距制约轨道设计方案的难题。

Research purposes： The intercity rail transit is mainly constructed on bridge with ballastless track to save land and reduce the influence of ballast dust on environment. When the CRTS I slab ballastless track is designed on the bridge for the intercity rail transit, the node space of fastening at beam gap cannot meet the specification requirements of 650 mm due to the small radius curve. This influences the implement of design scheme of ballastless track on bridge, so the research is done on finding out a feasible design scheme to solve the problem of node space of fastening at the end of the beam.Research conclusions： Through analyses and researches on the design parameters, design conditions and evaluation indexes for the rail deflection, elastic breaking - up space of widened rail when the rail broken at beam gap and shearing stress at end of concrete slab, and analyses of the stressed situation of track structure on the node space of fastening at end of beam, this paper proposes a feasible design scheme that the node space of fastening at the end of beam can be up to 725 mm. This breaks through the stipulation of the relative code, but solves the problem that the node space of fastening at the end of the beam influences the implement of track design scheme when ballastless track is used on bridge.