Study On Seismic Fragility Analysis Of RC Frame Structures With Different Seismic Fortification Levels Based On Random IDA Method

Performance-based seismic design theory has been widely concerned since the1990 s,and scholars from all over the world have carried out a wide range of research.The traditional anti-seismic thought is based on the protection of human life safety as the main fortification target.But the performance-based seismic design theory is aimed at improving the seismic performance of the structure,and it can predict the damage degree of the designed structure under the possibility of ground motion.The ability to improve the seismic performance of building structures under earthquakes is based on the core objectives of performance design.Reinforced concrete(RC)frame structure as a basic system of high-rise buildings of a city,widely used in the world.In recent years,the RC frame structure has suffered different degrees of damage or even collapse.At the same time,non-structural components in the structure also suffered varying degrees of damage.Therefore,it is of great significance to carry out performance-based seismic research.In this paper,a typical five-story frame structure is used as research object.Using OpenSEES to construct three RC frame structures with different fortification intensity,the stochastic IDA(incremental dynamic analysis)method is used to study the vulnerability of the above three RC frames structures.This article mainly includes the following sections:(1)Using PKPM software to design a typical 5-layer and 3-span RC frame structure,then use the finite element software OpenSEES to establish the finite element analysis model of 7-degree fortification,8 degree fortification and 9 degree fortification under the corresponding frame structure.(2)The stochastic IDA method is used to analyze the vulnerability of RC frame structure under different fortification intensity.The "randomness" is reflected in the randomness of structural parameters and the randomness of ground motion,taking into account the randomness of the structure and the ground motion Randomness makes the study of vulnerability more convincing.(3)The vulnerability of RC frame structure under different fortification intensity is studied,and the damage probability of different performance level under different fortification intensity is analyzed and compared.The necessity of improving fortification for primary fortified buildings is verified,such as hospitals,primary schools and so on.(4)The collapse probability of RC frame structure under the action of giant earthquake is studied,and the safety reserve coefficient of the structure under theexisting design rules is studied,and the suggestion of RC frame structure earthquake under the action of giant earthquake is given.(5)Focus on the research of nonstructural components in the 16 th World Conference on Earthquake held in Santiago.Based on related research results,mainly introduces the research of nonstructural wall,the study of isolation technology and the discussion about floor acceleration spectra during design phase.Finally,summarizes hot research directions on the nonstructural components and points out the the developing trends in the future.