重载铁路简支T形梁设计

Design of Heavy-haul Railway Simply Supported T-beams

铁路运输在国民经济发展中占据着重要地位,重载和高速为铁路运输两大发展方向,在山西中南部铁路通道桥梁设计中首次采用了300 kN轴重列车活载,简支梁采用的是预制后张法预应力混凝土T形梁。重载铁路对桥梁结构的承载力提出了更高的要求,而简支T梁的结构尺寸和质量均受到铁路运输的限制。设计中综合考虑结构承载力和梁体运输的要求,对桥面布置形式、梁体结构尺寸、混凝土强度等级选用和预应力筋布置形式及张拉力的确定等方面进行了计算分析和研究,提出了重载铁路系列简支T形梁设计方案,经实践检验设计方案是合理可行的。

Railway transportation occupies an important position in the national economic development;heavy haul and high speed are the two major development directions for the railway transportation.The bridge design of Shanxi-Henan-Shandong railway adopted for the first time 30t axle loading.The simply supported beams are the precast post-tensioned pre-stressed concrete T-beams.Higher requirements are put forward for the bearing capacity of bridge structure for heavy haul railways,while the size and weight of the simply supported T-beams are subjected to the limitations of railway transportation.Considering the structure bearing capacity and the transportation requirements in the design,analyses and researches were carried out in the respect of bridge deck arrangement,structure size,strength grades of concrete,layout of pre-stressed tendons and the determination of tensioning forces,etc.A series design of heavy haul railway simply supported T-beams was put forward.Practice proved the design is reasonable and feasible.