航站楼大跨径钢桁架拼接焊缝缺陷加固技术研究

Study on defect strengthening technology of splicing weld of long-span steel truss in terminal

拼接焊缝是大跨径钢桁架结构的薄弱环节,对于结构的安全性、可靠性和耐久性具有重要影响,针对拼接过程中出现的焊接质量问题,必须采取合适的加固措施才能消除安全隐患。张家口宁远机场改扩建工程航站楼钢桁架结构在拼接焊接过程中,出现了错位、漏焊、焊缝缺陷、螺纹钢筋塞缝等现象,从可操作性和经济性考虑,提出采用在桁架梁左右两侧外边缘平行于腹板的位置对称焊接钢板的加固施工方案,并从预加载、控制拼接板焊接顺序、承重支撑架卸载三方面制订了焊接加固施工控制措施,加固焊接完成后的残余应力较小,表明加固方案合理、安全、可行。

The splicing weld is the weak link of long-span steel truss structure,which has an important impact on the safety,reliability and durability of the structure.For the welding quality problems in the splicing process,appropriate reinforcement measures must be taken to eliminate the potential safety hazards.In the process of splicing and welding of the steel truss structure of the terminal building of Zhangjiakou Ningyuan airport reconstruction and expansion project,there were some phenomena,such as dislocation,missing welding,weld defects,and threaded reinforcement caulking.From the perspective of operability and economy,a reinforcement construction scheme was proposed to symmetrically weld steel plates at the position where the outer edges of the left and right sides of the truss beam were parallel to the web,and from the aspects of preloading,controlling the welding sequence of the splice plates.The welding reinforcement construction control measures were formulated from the three aspects of load-bearing support frame unloading.The residual stress after reinforcement welding was small,indicating that the reinforcement scheme was reasonable,safe and feasible.