中文摘要：

目的研究钢筋混凝土框架结构在地震作用下的连续性倒塌破坏机理，完善结构抗连续性倒塌的设计方法．方法采用建立的钢筋混凝土构件本构模型，对构件整体式建模，最终建立了8层空间框架结构模型．选取合适的构件破坏准则，对钢筋混凝土框架结构进行了地震作用下的连续性倒塌破坏全过程分析，分析了结构位移、弯矩等受力特性，探讨了构件破坏后的传力路径和结构连续倒塌破坏机理．结果框架结构中构件的破坏，一般始于框架梁的竖向大变形，完全倒塌的主要原因是总应变能的累积；结构首层是发生破坏的集中区域，当破坏范围自首层传至2层中跨后，结构将在短时间内完全倒塌；随着构件计算模型中捏缩效应系数的增大，框架结构整体破坏时间呈现先增大后减小的趋势；考虑计算模型中的峰值后强度退化段后，结构完全破坏的时间将会提前．结论“强柱弱梁”的受力机制有利于结构抵御连续倒塌；框架结构的首层是倒塌破坏的薄弱层；合理控制结构构件的剪跨比，可以提高结构整体的延性；若不考虑计算模型中的峰值后强度退化段，将会高估结构的抗连续倒塌能力．

英文摘要：

The main purpose of this paper is to research the collapse failure mechanism of rein- forced concrete frame and perfect the structure design method. A 8-storey 3-D frame model was developed in integral modeling method for further study on multi-story RC frame resistance to pro- gressive collapse under seismic adopting different calculation models. The failure criterion wasalso founded to obtain an overall collapse process of the frame under different conditions. The loading path and mechanism was analyzed and the time history of nodes was extracted. The results show that beams are proved to be the initiative failure parts of the frame while the main reason of col- lapse tend to be the accumulation of total strain energy. Damage centralized in first floor and it will not be long before the frame completely collapsing if damage is converted to upper floors. The ductility increased initially then reduced as the shear in the elements increased. The total time of frame collapse will be reduced if strength degradation is considered. The mechanism of strong col- umns and weak beams is beneficial to the resistance of the frame. The loading mechanism can be more reasonable with properly designed shear span ratio and controlling shear damage pattern. It is better to consider strength degradation to avoid over-estimating the resistance to progressive col- lapse of structure.