摘要
大跨度单层空间网格结构冗余度小,对缺陷比较敏感,施工效应的影响大,某些关键杆件的失效极易引起结构连续性倒塌。基于能量平衡原理,考虑构件失效前结构的已有变形,建立了空间网格结构及构件的能量平衡方程,推导出结构抗力与构件抗力的关系式。根据单层空间网格结构的失效模式,构建结构抗连续性倒塌的子结构模型,分析大跨度单层空间网格结构的抗连续性倒塌机制,即梁机制、拉结机制、梁-拉结相关机制以及压杆机制,提出了相应机制下抗力需求的理论计算方法和抗力-位移曲线,并通过数值算例分析验证了所提方法的正确性。此外,对备用荷载路径法进行了修正,提出用于抗连续性倒塌分析的考虑施工效应的等效荷载卸载法,将该方法通过算例进行验证后应用于世界大学生运动会主体育场结构的抗倒塌分析中,结果表明该方法更加接近实际,结果更为可靠。单层空间网格结构的抗倒塌机制在杆件失效后的内力重分布过程中发挥重要作用,世界大学生运动会主体育场结构具有较好的抗连续性倒塌性能。
Failure of key members may develop catastrophic progressive collapse for large-span single-layer spatial grid structures due to the characteristics of small redundancy, sensitivity to defect and large influence of construction effect. Considering existing deformation of some members of the structure before failure, the energy-balance equations of spatial grid structures and members were established based on the energy conservation principle. The relationship between resistance of structures and members was derived. The failure mode of single-layer spatial grid structures was given and the models of sub-structures were built. The anti-collapse mechanisms of large-span single-layer spatial grid structures, known as beam, tie, beam-tie and compression member mechanism were constructed. Then the theoretical calculation methods of resistance demand and the resistance-displacement curves were obtained. The validity of the proposed methods was validated through numerical examples. Novel improved nonlinear analytical method, known as equivalent load unloading method considering construction effect was introduced based on alternate load path method. This proposed method was eventually implemented in the mechanical analysis of the main stadium for the Universiade Sports Centre. It is indicated that the novel improved method is closer to practice and the result is more reliable. The anti-collapse mechanism of single-layer spatial grid structures plays an important role in internal force redistribution. It can be concluded that the roof of the main stadium for the Universiade Sports Centre has good resistance to progressive collapse.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第11期68-76,共9页
Journal of Building Structures
基金
国家自然科学基金项目(51608433
51408623)
华南理工大学亚热带建筑科学国家重点实验室项目(2017ZB23)
关键词
单层空间网格结构
连续性倒塌
抗倒塌机制
抗力需求
single-layer spatial grid structure
progressive collapse
anti-collapse mechanism
resistance demand
