某剧场平板网架屋盖鉴定与修复

Identification and Reinforcement of A Theater Grid Structure Roof

某剧场设计于1987年,竣工于1991年,屋盖为正放四角锥螺栓球平板网架。在改建过程中,因为使用功能升级及设备改造,对其进行检测、鉴定及加固,鉴定结果表明,屋盖网架结构不能满足安全性及耐久性要求。针对节点及杆件的不同受力特征,采用了新型综合加固方案:对于螺栓球节点采用附加扁钢节点板方式解决承载力不足问题,对于支座采用增设加劲肋解决其稳定性不足问题,采用贴焊钢管方法加固承载力不满足要求的杆件,采用外包套管方法加固受压稳定性不满足要求的杆件。外包套管加固方法减少了网架结构加固中的焊接作业,消除了焊接应力的影响以及焊接过程中钢管高温软化可能导致的非预期破坏。采用综合加固方案大大缩短了施工作业时间,取得了良好的社会与经济效益,为以后类似改造工程提供了借鉴。

A theater designed in 1987,completed in 1991,the roof is orthogonal square pyramid grid structure with bolted-ball joint. In the process of renovation,due to the use function upgrades and equipment transformation,the original grid structure can＇t meet the safety and durability requirements,the detection,identification and reinforcement are needed. According to the reinforcement principle of the structure,a new reinforcement method is adopted for the different force characteristics of the joints and the bars. For the boltedball joint,the additional flat steel gussets are used to reinforce the anchorage ribs,the welded steel pipe method is used to strengthen the the bar which bearing capacity does not meet the requirements,the outer sleeve reinforcement is used to strengthen the bar which the pressure stability does not meet the requirements. The bearing capacity of the joint,the problem of the safety of the bar and the welding work in the reinforcement of the truss structure are reduced,the influence of the welding stress and the possible unexpected damage from high temperature softening of the steel pipe during the welding process is effectively eliminated,the construction time is greatly shorted,and good social and economic benefits is achieved. It also provides a reference for similar project.