一台德国利勃海尔公司生产的LG1200型桁架式汽车起重机(额定起重量为200 t),在一次作业中,因吊钩回荡撞击在吊臂第一节的斜撑杆上,造成2根斜撑杆弯曲变形、2根斜撑杆断裂,严重地影响了该节吊臂的刚度和结构稳定性,必须进行修复。1.修复方案 本着经济实用的原则,经现场查看认为,对4根弯曲变形及断裂的斜撑杆,可去除断裂和严重弯曲部分,剩余部分可再利用,去除部分可采用与之性能相近的无缝钢管代替,即用角向砂轮切去其断裂和严重弯曲的部分(避免因用氧乙炔焰切割而影响主杆),并对主杆上 A LG1200 truss truck crane (nominal capacity of 200 t) produced by Liebherr in Germany, in one operation, due to the reverberating impact of the hook on the diagonal strut in the first section of the boom, two inclined Bending bar bending deformation, two diagonal brace bar fracture, severely affected the section of the boom stiffness and structural stability, must be repaired. 1. The repair plan is based on the principle of economy and practicability. According to the on-site inspection, the four diagonal braces with bending deformation and fracture can remove the fracture and the serious bending part, and the rest can be reused, and the removed part can be used with similar performance Of the seamless steel pipe instead, that is, the use of angle grinding wheel cut its severed and severely bent part (to avoid the use of oxyacetylene flame cutting and affect the main rod), and on the pole