整体桁架节点腹杆及高强度螺栓连接受力特性分析

Analysis of Force Characteristics of Whole Trussed Joints Web Member and High-strength Bolted Connection

整体式桁架节点与腹杆的连接方式有插入式和对接式。插入式连接方式相对于对接式连接方式而言其制造相对简单,但存在安装过程中摩擦面易损伤、需加大节点板大小、螺栓排列数多等缺点。两者腹杆和节点之间传力途径的最大区别为,插入式只有2个侧向摩擦面,而对接式有4个摩擦面,在目前公铁两用或公轨两用桥梁中2种方式均有使用。随着桥梁技术的发展,桥梁跨径变大、荷载承载能力要求更高,致使杆件断面尺寸也变大,从而需要布置更多螺栓。而当螺栓数量增加后,是按2个面布置还是4个面布置,对节点整体设计影响较大。以重庆曾家岩嘉陵江大桥典型节点为研究对象,分析对比2种不同连接方式的螺栓布置方法,分析结果可供同类桥梁桁架节点设计参考。

Connection between whole trussed joints and web member includes insert type and but connection. Comparing with butt connection, the insert connection features easy manufacturing, but it has the disadvantages like easily damaged friction face during installation, larger joint boards and more bolt arrays. The biggest difference of force transfer routes between web member and joints of the two connections is ： the insert connection has 2 lateral friction faces and the butt connection has 4 friction faces, both these two connection methods are used in road/rail bridges or common rail bridges. With the development of bridge technology, larger span of bridges and higher demand for bearing ability of bridges, the sectional dimension of web member is increasing, which needs more bolts. For increasing number of bolts, the 2 faces arrangement and 4 faces arrangement results in significant influence on overall design of joints. This paper studies typical joints at Chongqing Zengjiayan Jialing River Bridge, the bolt arrangement methods of the two different connections were analyzed and compared, the results of analysis may be used as reference for truss joint design in similar bridges.