【摘要】 在建筑结构的抗震设计中,常常希望通过合理的设计,使结构能按预期的强柱弱梁失效模式破坏,通常通过提高柱端弯矩增大系数(COF)使结构满足"强柱弱梁"的要求。该文考虑上层、下层、中间层这3类层间失效模式,采用结构可靠度理论,对钢筋混凝土框架结构最可能倒塌失效模式及完全梁铰式失效模式的相对发生概率进行研究。算例结果表明:当COF较小时,结构最可能失效模式为中层失效模式;当COF较大时,则结构倒塌由上层失效模式控制。研究结果可为罕遇或特大地震作用下结构的抗倒塌设计提供参考。更多还原

【Abstract】 A structure is usually designed with a relative higher column over-design factor(COF) to ensure that the structure satisfies strong-column-weak-beam(SCWB) design requirements.In this study,the theory of structural reliability is employed to investigate the most likely failure modes of reinforced concrete frame structures and the relative occurrence probability of an entire beam hinging failure mode considering the upper,middle,and lower collapse modes of structures.The analysis results of an example demonstrate that the middle collapse mode is the most likely failure mode with lower COF.If the value of COF is larger than 2.0,the upper collapse mode controls the collapse failure process of structures.This research can provide some useful guidelines for the collapse resistant design of structures under major or very rare earthquakes.更多还原