梅江会展中心张弦桁架抗连续倒塌分析  

Analysis on progressive collapse resistance of truss string structure of Meijiang Exhibition Center

作　　者：朱奕锋[1,2] 冯健[1] 蔡建国[1] 庄丽萍[1] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,江苏南京210096 [2]中冶建筑研究总院有限公司,北京100088

出　　处：《建筑结构学报》2013年第3期45-53,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(50478075)

摘　　要：通过对天津梅江会展中心张弦桁架移除关键构件后的残余结构的承载力分析,得到张弦结构的支座、边索和边跨桁架支座处下弦杆等关键构件的破坏对结构承载力影响最大;为了模拟杆件失效前静力荷载产生的初始变形对结构连续倒塌的影响,采用考虑初始变形的全动力等效荷载瞬时卸载法模拟杆件失效。对支座、边索和边跨桁架支座处下弦杆失效进行连续倒塌动力分析,研究了纵向联系桁架对张弦结构抗连续倒塌的作用,得到平面张弦桁架通过纵向联系桁架组装成一整体,其整体性随着纵向联系构件抗弯刚度的增大而提高,共同作用效果明显。在此基础上,利用山墙的抗风柱,将边跨张弦桁架改变为多支点支承的普通桁架,设计时该抗风柱不仅承担水平风荷载,还承担竖向荷载,从而提高结构的抗连续倒塌能力。并根据该工程的特点提出集桁架支座、张拉端(锚固端)和桁架下弦管于一体的铸钢节点构造,不仅满足建筑要求,还使得该处节点承载力大大加强,可供相关工程参考。On the basis of the capacity analysis of damaged truss string structure, key members of truss string structure of Tianjin Meijiang Exhibition Centre were identified. The damage of the key members such as support, marginal cable and bottom chord of the side span truss near the support has the most effect on the bearing capacity of structre. Full dynamic equivalent load transient unloading method was used to simulate the failure member, which could effectively simulate initial deformation at the static load before member fail. Progressive collapse dynamic analysis was carried out for the support loss, cable of side span loss and down-chord of side span near support loss. The effect of the longitudinal connection truss on the progressive collapse resistance of truss string structure was discussed. It is concluded that plane truss string structure is assembled as a whole through longitudinal connection trusses, whose integrity is strengthened with flexural rigidity of the longitudinal association connection truss, and the combined action is obvious. Utilizing the wind columns of the gable direction, string turss of side span was replaced by common truss with multi-point support. It can improve the progressive collapse resistance capacity of the structure, which is intended to not only resist horizontal wind load, but also resist vertical loads in design. In addition, the cast steel joint was put forward for the connection of cable and truss and linking the support according to characteristics of the project, which can not only meet construction requirements, but also greatly enhance the nodal capacity in the place and provide a reference for engineering application.

关 键 词：张弦结构 纵向联系桁架 数值分析 连续倒塌 关键构件 设计方法 

分 类 号：TU393.304[建筑科学—结构工程]