Lots of scholars both at home and abroad always focus on the regular structures by using the nonlinear-static method for structural collapse analysis in recent years.The nonlinearstatic method is very practical and convenient for researchers in structures studies.However

the progressive collapse study for the irregular structures was relatively less.In this paper

the research of progressive collapse acts of vertically irregular frame structures was carried out with the structural finite element software SAP2000based on the alternate path method.In order to show the collapse law of the remaining structures clearly

the columns of different parts in the same structure and the columns of the same part in different structures were removed

and then the bearing capacity of the relevant reaming structures was compared.After the comparison and analysis

several useful methods for progressive collapse prevention were set out.The analysis result shows that the bearing capacity of the remaining structure goes down with the tower layer increasing and the position of the target column moves up after removing the target column.It is very helpful to strengthen the horizontal elements near the top of podiums which can make the remaining structure achieve its catenary effect and prevent sudden collapse of the remaining structure without obvious signs.In the future

the designers and researchers should pay more attentions on the sensitive parts of the irregular structures

and strengthen the parts mentioned above to prevent the occurrence of the progressive collapse of the irregular structures.