钢索塔斜拉桥主桥钢结构焊接工艺研究

Study on welding technology of main bridge steel structure of cable stayed bridge with steel cable tower

提出了改进的钢索塔斜拉桥主桥钢结构焊接工艺。采用CO_(2)气体保护焊焊接钢箱梁和钢板,当钢结构温度低于0℃时预热母材,使其温度保持在22℃。定位焊钢结构,调整焊接焊条和焊丝位置,并实时检测焊接参数、焊接顺序、层间温度。采用超声波无损检测焊缝缺陷,完成钢结构焊接。通过实验,分别测试了钢结构焊接试件的抗疲劳断裂性能、最高硬度值和不同温度下的屈服强度,结果表明,采用所提出的工艺减缓了焊件的疲劳裂纹扩展速率,提高了其硬度值和屈服强度,主桥钢结构的力学性能要优于传统焊接工艺。

The welding process of the steel structure of the main bridge of the cable tower cable-stayed bridge is proposed.The steel box girder and steel plate are welded by CO_(2)gas shielded welding.When the steel structure temperature is lower than 0℃,the base metal is preheated to keep its temperature at 22℃.By locating the welding steel structure,adjusting the position of welding electrode and welding wire,testing the detect the welding parameters,welding sequence and interpass temperature in real time,it use ultrasonic nondestructive testing to detect weld defects,and completes the steel structure welding.The fatigue fracture resistance,the maximum hardness value and the yield strength at different temperatures of the welded steel structure specimens are tested.The results show that the proposed process slows down the fatigue crack growth rate of the welding process,improves its hardness value and yield strength,and the mechanical properties of the main bridge steel structure are better than the traditional welding process.