主要设计参数对规则RC框架结构抗连续倒塌性能的影响

INFLUENCES OF PRIMARY DESIGN PARAMETERS ON PROGRESSIVE COLLAPSE RESISTANCE OF REGULAR RC FRAME STRUCTURES

  • 摘要: 连续倒塌是指由意外事件造成工程结构的局部破坏并形成连锁反应,最终导致结构大范围破坏甚至整体倒塌,其中结构系统的冗余承载力对其抗连续倒塌性能具有显著影响。为满足工程快速评估的需要,分析、总结了主要设计参数对规则框架结构抗连续倒塌性能的影响规律。按照规范设计了18个典型钢筋混凝土(RC)规则框架,分别考虑了不同抗震设防烈度、结构总楼层数、结构跨度3个主要设计参数对结构冗余承载力的影响;采用纤维梁模型建立了所有典型框架的有限元模型,其中梁采用T形截面建模考虑有效翼缘宽度范围内楼板的贡献;采用非线性动力拆除构件法分析了框架在不同部位发生初始破坏时的连续倒塌响应,以及主要设计参数对结构连续倒塌影响的规律。

     

    Abstract: Progressive collapse is defined as the localized damage propagating throughout a structural system, which is triggered by the initial failure of critical structural element(s) caused by abnormal loads, eventually resulting in a partial or total collapse of the entire structural system. The progressive collapse resistance of the structural system is significantly affected by its redundant strength. The influences of primary design parameters on the progressive collapse resistance of regular reinforced concrete (RC) frame structures were analyzed and summarized to satisfy the requirement of rapid engineering assessment. Eighteen typical RC frames with regular configurations were designed according to the codes in which the effects of three design parameters, i.e., seismic fortification intensity, total number of structural floors and structural span, on structural redundant strength were considered. The numerical models of the frames were established using fiber beam elements, in which beams were modeled with T-shaped sections considering the contribution of the floor slab within the effective flange width. The nonlinear dynamic alternate path method was utilized to analyze the progressive collapse responses of these frames when initial failure occurred at different locations, and the influences of the primary design parameters on the progressive collapse resistance of the structures were studied.

     

/

返回文章
返回