三主桁连续钢桁拱桥整体节点有限元分析

Finite element analysis of integral joint in three-truss continuous steel truss arch bridge

东平水道桥是武广高速铁路上一座四线铁路桁架拱桥,主跨结构为99m+242m+99m的三主桁连续钢桁拱,主桁采用整体节点形式,三主桁内力分析表明中桁处受力最大。节点板联结着主桁、腹杆、横梁、平联等各类杆件,结构及受力均较复杂,节点应力分布是设计中的关键问题之一。文章利用有限元程序对其特殊位置节点板进行应力分析,研究了其应力分布及传力特性,为设计提供依据和给同类桥梁提供参考。研究表明通过调整节点构造和板件刚度,节点具有足够的受力与传力功能。

The dongpingshuidao bridge is a four-line railway truss arch bridge on the Wuhan-Guangzhou high-speed railway.The bridge is a three-truss continuous stell truss arch bridge,whose main span is 99＋242＋99 re.The main trusses adopt the integral joint type,and the internal force analysis showed that the mid-truss has the greatest force. The structure and stress of the gusset plate are all complicated for that it connected with all kinds of elements,such as mian truss,web member,cross beam and bracing cot.Node stress distribution is one of the key problems in the design. The paper take advantage of finite element program to study the stress distribution and force-transfer characteristic of the special joint. It can provide a basis for design and a reference for similar bridges on future. Study shows that： the joint has the sufficient function of bearing and transfer force by adjusting the node structure and stiffness of plates.