大跨度钢结构的抗连续性倒塌设计

Progressive Collapse Resistance Design of Long Span Steel Structures

为了实现大跨度钢结构的抗连续性倒塌设计目标,从结构体系布置的角度出发,对不同形式的大跨度钢结构,提出抗连续性倒塌设计的实用方法与措施:即对连续多榀平面桁架等平面结构体系,增设横向联系梁;对环向布置的结构体系,增设环形联系梁;对弦支预应力结构,拆分传力路径。关于抗连续性倒塌分析方法,根据不同的体系特点,说明了静力线性法、静力非线性法及动力非线性法的适用范围,并导出了局部构件失效时的结构分析列式。基于动力非线性分析,提出了根据构件破坏前后结构刚度矩阵条件数变化系数η,来判断大跨度钢结构刚度矩阵病态程度的方法。通过3个工程实例验证了所提出的结构抗连续性倒塌概念设计措施及计算方法。

In order to ensure the progressive collapse resistance design of long span steel structures,several practical methods or measures were proposed for the structure design based on the different structure systems.The methods were the lateral beam method for plane truss structure systems,the circular reinforced beam method for radial layout truss structures,and the separated load path method for the suspend dome structures,respectively.In the aspect of calculating methods,the suitable scopes of the linear static method,the nonlinear static method,and the nonlinear dynamic method were concluded.The computation formulas for the structures with local member failure were derived.The variation coefficient of the stiffness matrix condition number before and after the member failure was proposed to judge the illness of the matrix.Three examples proved the design measures and the calculating methods.