Anti-collapse Analysis For Double Layer Spherical Reticulated Shell Of Gymnasium Of Yaojie Coal Group Co. Ltd.

As a kind of large-span spatial structure,double layer spherical reticulated shell has both beautiful shape and flexible structural arrangement,that is also why it can be increasingly used in large industrial and civil buildings,but the continuous collapse happened to such architectural structures often results in serious consequences.Based on ABAQUS,a famous finite element analysis software,and the alternative load path method,this paper researches a double layer steel reticulated shell structure of a gymnasium in Lanzhou City,relevant nonlinear static and dynamic analysis are also included in researching.The content and conclusion of this study are as follows,(1)Static analysis and linear elastic modal analysis are both used to study the distribution law of critical structural components.The results show that some critical bars are mainly distributed in the second or the third circle of the whole structure,others are located in the lower structure and near the supports.And if those structure components are damaged,the carrying capacity and progressive collapse-resisting performance of the whole structure would be largely weakened.(2)Nonlinear buckling analysis for both complete structure and varying degrees of damaged structure showed that even the most severely damaged structure still has eligible carrying capacity and adequate redundancy.With the increase of external load,the structure will collapse eventually,but the failure mechanism of this structure can be certain with the comparison of the evolution of plasticity inside the structure and the maximum horizontal displacement of nodes: the collapse is caused by instability failure due to large displacement of nodes instead of strength failure due to the evolution of plasticity.(3)Dynamic effect of the critical component during the progressive collapse is considered in the nonlinear dynamic analysis,it showed that one single member bar's crash would hardly cause the progressive collapse of the complete structure.After the destruction of one single upper chord bar or a web member bar in the middle,the maximum node displacement would increase a little,but it is still in the normal range.And if one single bottom chord bar is destroyed,some adjacent member bars would be damaged due to instability failure,but the complete structure would not collapse,it is still safe.(4)Through the study we found that if it is allowable,the sectional dimensions of some unimportant components could be enlarged to increase the resistance to progressive collapse of damaged structure,though it can hardly ensure the safety of complete structure.(5)This paper also worked on the load amplification factor in the static analysis,and the appropriate value of this parameter should be 1.6 for this structure.