中大跨高速铁路简支组合梁设计研究

RESEARCH ON DESIGN OF MIDDLE AND LONG SPAN SIMPLY SUPPORTED COMPOSITE GIRDERS FOR HIGH-SPEED RAILWAY

我国铁路桥梁领域常用预应力混凝土简支梁或连续梁。传统预应力混凝土梁存在跨越能力有限,现场浇筑施工速度慢等缺陷,难以适应我国高速铁路桥梁快速建设的需求。钢-混凝土组合梁以其优良的力学性能和便捷的施工方法在世界范围内得到快速发展。通过整理国内外铁路组合桥现有研究成果,探究钢-混凝土简支组合梁在40～64 m跨度的适用性,分别研究了施工方法、混凝土板厚、二期铺装、双重组合作用等参数带来的影响。研究表明:组合桥方案能有效降低自重、提高施工速度、拓展标准跨度,同时结构各项指标满足高速铁路要求,铁路组合梁建议的经济跨度为48 m。

Prestressed concrete girders have been widely used in railway bridges in China. Traditional prestressed concrete girders have the defects of limited spanning capacity and slow construction speed of on-site pouring, which is difficult to meet the requirements of rapid development of high-speed railway bridges in China. Steel-concrete composite girders have been rapidly developed worldwide due to their excellent mechanical properties and convenient construction methods.The paper explored the applicability of the simply supported composite girder in the 40 ?64 m span by arranging the recent research results of the domestic and international railway composite bridges.The effects of construction methods, concrete slab thickness, second-stage dead load , and double composite actions were studied. The research showed that the composite bridge could effectively reduce the self-weight, improve the construction speed and expand the standard span, meanwhile, the key indicators could meet the requirements of high-speed railway. The proposed economic span of the railway composite bridge is 48 m.