Study on Collapse Mechanism of Single-span Frame Structure under Extremely Rare Earthquake
ith the concept of extremely rare earthquake proposed in the fifth generation of Seismic Ground Motion Parameter Zonation Map of China(GB 18306-2015),it is necessary to explore the collapse mechanism of single-span frame structures under extremely rare earthquake.Using the explicit dynamic analysis software ANSYS/LS-DYNA,the collapse process of the single span frame structure under the action of rare earthquakes is simulated.Through reasonable selection of parameters and models,the whole process of collapse and failure of the single span frame structure is reproduced.The collapse and failure mechanism of single-span frame structures under extremely rare earthquake is revealed,which provides a theoretical basis for the identification and strengthening of existing single-span frame structures.The results show that the main reason for the collapse of the single-span frame structure is that the anti-seismic defense line of the single-span frame structure is thinner than that of the multi-span structure,the structure redundancy is insufficient,and the plastic hinge at the bottom column end of the structure is the plastic hinge.