The Chinese Journal of Nonferrous Metals
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|第11卷 第1期 总第57期 2014年2月|
(中南大学 土木工程学院，湖南 长沙 410075)
摘 要: DPSD桥是一座新建双线高速铁路新型大跨连续钢桁拱桥，边跨跨度只有中跨的1/3左右。基于该桥的结构特点，进行全桥空间有限元和关键节点的局部精细有限元分析。研究结果表明：这种“双拱肋+下弦杆+边纵梁”的结构，弥补了边跨太小的缺点，桥梁整体刚度大，静活载作用下的挠跨比为1/2 344；下弦杆只受节点荷载，受力状态简单；一部分桥面荷载由边纵梁传至横梁，改善了桥面系和横梁的受力状态，桥梁的整体受力满足强度要求；桁拱关键节点的节点板边缘采用不同的曲线较光滑相连，尽管形状不规则，但应力集中程度较小，节点局部受力均处于弹性状态。该新型结构用于中、边跨跨度之比3以上的大跨度铁路桥是合适的。
（School of Civil Engineering, Central South University，Changsha 410075，China）
Abstract:DPSD bridge is a new type continuous steel truss arch bridge built newly with large span and double-track high speed railway. Its side span is only one third of the main span. On the basis of the structural characteristics of the bridge, spatial finite element analysis of the whole bridge and the refined local finite element analysis of a key node were completed. The results show that the structure of double arch rib plus lower chord plus side stringer makes up the disadvantages caused by the short side span and increases the integral stiffness of the bridge . The ratio of the deflection to the main span under the action of static live load is 1/2 344. The lower chords are only under the action of nodal forces and their stress condition is simple. Part of the deck load transmits to the cross beams by the side stringers and improves the stress condition of the floor system and the cross beams. The overall stress of bridge meet the demand of strength. The edge of the nodal plate of the truss arch key nodes is connected by different curves smoothly, thus the degree of stress concentration is small and the nodes are under elastic state, although the shape of the nodal plate is irregular and the forces of the relative components are large. This new type structure is suitable for the long span railway bridges with the ratio of main span to side span larger than 3.
Key words: high speed railway；new type of steel truss arch bridge；finite element；stiffness；strength