Dynamic Model of Alternative Load Path for Structural Progressive Collapse

The alternative load path method is widely used to analyze the structural progressive collapse in civil engineering.According to this method,an equivalent dynamic alternative load path model is built to analyze the dynamic behaviors of built-in beams when the supporting column in the middle span of the beam is removed instantaneously by blast loads.The curves of the maximum displacement of the beam are calculated for dynamic loads,and they are two times greater than the corresponding static displacement.It shows that dynamic responses of beams after removing the supporting column abruptly can not be neglected.The equivalent dynamic alternative load path model is helpful to confirm the equivalent static loads in the equivalent static analysis of the structural progressive collapse.