Performance Based Seismic Fragility Of Steel Frame With Slit RC Wall Structure

Steel frame with slit RC wall structure(SRCW)is composed of steel frame,infilled slit RC wall and shear connectors.Compared with ordinary reinforced concrete RC walls,the lateral stiffness of RC walls is weakened due to the vertical slits.Under the force of horizontal earthquakes,a large number of small cracks are generated between the slit walls,and the deformation and energy consumption capacity are significantly enhanced.The application of reinforced concrete RC walls with vertical slits to super high-rise buildings will effectively improve the lateral stiffness of the structure and enhance the stability,safety,seismic and wind resistance of the structure.At present,some scholars have carried out systematic test and theoretical research on the seismic mechanism of SRCW structure,and obtained a series of research results.However,the related research on the performance index and seismic fragility of SRCW structure has not been published in the literature.In this paper,the statistical analysis of the existing SRCW structure test data,combined with the Park-Ang damage model,quantifies the performance index of this type of structure in terms of the interlayer drift ratio under different seismic levels,through the curved structure and the shear type.Through the curved structure and the shear structure comparative study of seismic fragility analysis methods of structures,reasonable selection of the best analysis method was made,and seismic fragility curves of SRCW structure based on behavior with this method were constructed,and the seismic fragility and collapse performance of such structures was evaluated in high-intensity areas in my country performance.The research work carried out in this paper is of great significance for improving the behavioral design method of SRCW structure and popularizing the engineering application of this type of structure.The main research contents of this paper are as follows:(1)The SRCW structure test specimens completed at home and abroad have been statistically analyzed,combined with the modified Park-Ang damage model,the collapse criterion of the SRCW structure was proposed,and the SRCW structure was established in normal occupy(NO),immediately operational(IO),damage control(DC),life safety(LS),collapse prevention(CP)and collapse(C)state.The performance index of the six damage states provided a basis for the seismic fragility alanysis of the SRCW structure based on the behavior.(2)The general finite element program Perform-3D was used to establish the macroscopic finite element model of the typical test specimen of SRCW,to verify the rationality and reliability of the finite element analysis,and to provide a basis for the seismic fragility analysis of the SRCW structure.(3)Taking SRCW structure(curved type)and steel frame structure(shear type)as objects,40 seismic waves were selected reasonably,and two types of structural standard calculation examples of 8-degree area,5-story and 10-story were designed,based on the Perform-3D platform established a finite element model.Based on the Incremental Dynamic Analysis and Latin hypercube sampling methods,two types of structural seismic fragility curves were constructed.The advantages and disadvantages of the two methods were systematically evaluated and the optimal analytical method were obtained.(4)Considering the impact of the number of floors,a total of 5,10,20,and 30-story SRCW structural calculation examples were designed,and 40 seismic records from the Pacific Earthquake Engineering Research Center(Peer)in the United States were selected.The optimal method constructed a seismic fragility curve based on the behavior of the case and determined the CMR of SRCW,and evaluated the seismic fragility and collapse performance of low-rise,multi-story,high-rise and super high-rise SRCW structures.