The steel roof of the Pierre Mauroy Stadium in Lille (France) is supported by two mega-trusses, each 200 m long and 16 m high. The main design challenge was to propose a technique to assemble the elements of the mega-trusses with minimum welding on site to save time, with a limited number of bolts for aesthetic reasons. The members of the compression chords were assembled using full contact and those of the tension chords were joined with cover-plates and a single pin instead of multiple bolts. During erection of the mega-trusses, an unknown instability phenomenon appeared on the cover-plates used only to transmit tension forces. The lifting operations were stopped immediately to maintain safety. After verifications, it was concluded that the final design based on Eurocodes was correct for both the service conditions and construction stages. Large parametric studies with nonlinear analyses were conducted to understand the origin of this behavior. Ignoring this phenomenon would be impossible even if the tension forces were smaller for the service life. Thus, new design requirements were defined to consider the phenomenon and reinforcement was added to some cover-plates to secure the structure. This article presents the observed phenomenon, the main numerical simulations to understand the origin of the instability, and the design requirements to verify the safety of this type of joint.

法国里尔的皮埃尔·毛罗伊体育场的钢屋顶由两个巨型桁架支撑，每个巨型桁架长200 m，高16 m。主要的设计挑战是提出一种技术，以最小的现场焊接来组装大型桁架的元件，以节省时间，并且出于美学原因，使用有限数量的螺栓。压紧弦杆的构件采用完全接触的方式组装，而张紧弦杆的构件则用盖板和单个销钉代替多个螺栓连接在一起。在巨型桁架的安装过程中，在仅用于传递拉力的盖板上出现了未知的不稳定性现象。为了安全起见，立即停止了起重作业。经过验证，得出的结论是，基于欧洲规范的最终设计对于使用条件和施工阶段都是正确的。进行了带有非线性分析的大型参数研究，以了解这种行为的起源。即使拉力在使用寿命内较小，也无法忽略这种现象。因此，定义了新的设计要求以考虑该现象，并在某些盖板上增加了加固以固定结构。本文介绍了观察到的现象，了解不稳定性来源的主要数值模拟以及验证此类接头安全性的设计要求。定义了新的设计要求以考虑该现象，并在某些盖板上增加了加固以固定结构。本文介绍了观察到的现象，了解不稳定性来源的主要数值模拟以及验证此类接头安全性的设计要求。定义了新的设计要求以考虑该现象，并在某些盖板上增加了加固以固定结构。本文介绍了观察到的现象，了解不稳定性来源的主要数值模拟以及验证此类接头安全性的设计要求。