大跨度钢桁架梁焊接拼接节点加固设计及监测分析

REINFORCEMENT DESIGN AND MONITORING ANALYSIS OF THE LONG-SPAN STEEL TRUSS GIRDER WITH WELDED SPLICE JOINTS

大跨度钢桁架常采用工厂分段制作、现场焊接拼接连接的方法进行施工安装,杆件拼接连接焊接施工质量直接影响结构承载能力和结构安全性。针对工程检测中发现的杆件拼接焊接的严重质量缺陷,考虑构件受力特点,采用腹板补强增大截面法进行焊接拼接节点加固。为了验证加固设计的有效性,对构件焊接拼接节点处的受力性能进行数值模拟分析和施工过程节点应力状态监测。通过对比分析数值模拟结果与钢桁架梁焊接拼接节点处应变实测结果,验证钢桁架梁采用腹板补强增大截面法进行焊接拼接节点加固的传力有效性。

Long-span steel truss is often produced in section in the factory and are installed by weld splice in site.Construction quality of weld splice directly affect the bearing capacity and the security of a structure.Based on the serious quality problems of web welding found by project detection, considering the component mechanical characteristics,web reinforcement enlarged cross section method was adopted to reinforce the welded splice joints.In order to verify the validity of the reinforcement design,the numerical simulation was used to analyse mechanical performance and the monitoring was adopted to determine the stress state of welded splice joints in the process of construction.Based on the comparison and analysis of the results of numerical simulation and strain test,it was proved that web reinforcement enlarged cross section method became effective on the transfer of force.