铁路桥梁刚度描述方法

针对我国新建桥梁跨度和结构形式远远超出现有桥梁设计规范的适用条件,以及国内外桥梁刚度指标和取值存在较大差异,进行铁路桥梁刚度描述方法和预应力混凝土连续梁(刚构)桥刚度的限值研究。提出一种铁路桥梁刚度的统一描述方法,即采用设计荷载下的梁端处桥面(轨面)的横向、竖向转角和扭转角及非梁端处桥面(轨面)的横向、竖向转角和扭转角沿桥纵向的变化率(即曲率)描述桥梁刚度,并推导出大跨度铁路预应力混凝土连续梁(刚构)桥刚度设计参考限值。该方法不仅能方便描述简支梁的刚度问题,与现有规范相衔接,而且能描述规范所不能涵盖的大跨度桥梁和特殊桥梁结构的刚度问题。通过代表性桥梁的车桥系统动力响应计算分析,证明了统一描述方法的可行性和较好的统一性。

Method for Describing the Stiffness of Railway Bridges

Since the spans and structure forms of the newly-built bridges in China are far beyond the conditions of current criteria for bridge design,there are also great differences between bridge rigidity indices and values home and abroad,researches have been carried through on the method for describing the rigidity of railway bridge as well as rigidity limit values for prestressed concrete continuous beam(rigid frame) bridges.A uniform method is put forward for describing the rigidity of railway bridges.Namely,bridge rigidity is described by using the transverse,vertical and twist angle of the bridge deck(rail surface) at the beam end,and the vertical change rate(curvature) for the transverse,vertical and twist angle of the bridge deck(rail surface) at non-beam end under design load.Reference limit values are put forward for the rigidity design of long-span prestressed concrete continuous beam(rigid frame) bridges.The method not only can describe expediently the rigidity of simple supported beam and link up the current criteria,but also can describe the rigidity of long-span bridges and special bridge structures which are not covered in the criteria.The feasibility and unification of the uniform method has been proved by calculation and analysis for the dynamic response of the vehicle-bridge system of a typical bridge.