武慧芬¹，惠云玲¹，弓俊青¹，张家启²，杨建平²，郭春红²
（1 国家工业建筑诊断与改造工程技术研究中心，北京100088; 2 中冶建筑研究总院有限公司，北京100088）

[摘要] 某办公楼中的钢桁架结构，在施工过程中产生了超出预期的挠度，通过对施工过程进行现场调查，对焊缝质量进行检测，对结构进行加载试验，并考虑平面结构的空问协同工作进行分析计算，结果表明挠度是在钢桁架杆件安装施工过程中产生的，对结构的安全未产生大的影响，结构主要的安全隐患在于其自身的连接缺陷。在此基础上，提出了加固处理方案，加强节点连接，弥补焊缝缺陷，提高桁架的平面外稳定性。该方案便于实施，费用低，快速圆满地解决了工程问题。
[关键词] 钢桁架；下挠；鉴定；加固

Appraisal and strengthening of a deflection exceeding steel truss
Wu Huifen¹, Hui Yunling¹, Gong Junqing¹, Zhang Jiaqi², Yang Jianping², Guo Chunhong²
(1 National Engineering Reserch Center on Diagnosis and Rehebilitation oflndustrial Building, Beijing 100088, China; 2 Central Research Institute of Building and Construction of MCC, Beijing 100088, China)

Abstract: The deflection of a steel truss in the constructing process exceeded largely the expected value. Authors investigated the constructing process, detected the weld and conducted a loading test with the construction. The space effect was thought to analyze the construction. The deflection was created just during the early constructing process and did not affect the security ofthe construction severely. The main factor affecting the construction security is the weakness of the connections. Thus,a strengthening way was proposed, which required enhancing the joints connection, eliminating the weld defects and improving the external stability of the truss. The strengthening ways were carried out, showing the scheme was simple and economical.
Keywords: steeltruss; deflecting; appraisal;  strengthening