Study On Seismic Response Of Near-fault Hanging Wall/Foot-wall Paramaters For Isolated Frame-Shearwall Structure

China is an earthquake-prone country.In recent large-scale earthquake surveys,it has been found that ground motions have caused great damage to the building structure in the near-fault-affected area,and are often accompanied by the effect of the upper and lower plate due to the asymmetric distribution of oblique faults.Earthquake damage studies have shown that the seismic performance of a large number of short-period structures in the overhang area has been severely affected,while long-period structures within the footwall area have suffered more damage,but the researchers focus It is mostly the influence of the top plate ground motion on the dynamic response of the short-period structure,while neglecting the influence of the change of fault parameters on the ground motion of the upper and lower plates and its influence on the dynamic response of the structure.In view of the above problems,the frame-shear wall structure of the seismic isolation device is set as the research object,and different fault parameters(magnitude,fault dip angle,and upper buried depth)affecting the upper and lower plate ground motions are synthesized based on the NGA model.The influence of the fault parameters on the dynamic response of the isolated frame-shear wall structure was investigated by using the upper and lower plate ground motions with different fault parameters.The main research work and conclusions of this paper are as follows:(1)Based on the 250 on-board seismic records and 285 on-site seismic records of NGA-West2 database,the peak ground accelerations and response spectrum accelerations of the upper and lower ground motions were performed for three ground motion parameters attenuation relation models: ASK14,CB14,and CY14.The prediction error analysis found that the prediction error of the ASK14 model for the peak acceleration of the upper plate earthquake was smaller than that of the CB14 and CY14 models,while the prediction error for the lower plate earthquake was comparable to other models.(2)In the short-cycle range,an increase in magnitude will increase the overhang effect,and the magnitude of the overhang effect will gradually decrease with the increase of fault distance.With the increase of fault distance,the upper buried depth will increase.The effect on the hanging wall effect gradually decreases;in the middle and long period,the effect of the hanging wall decreases with increasing magnitude,and as the distance between the faults increases,the influence of the change in magnitude on the hanging wall effect gradually increases.Increasing,the effect of the overhang from the far area of the fault is more significantly affected by the depth of the upper boundary of the fault.The reduction of fault dip angle will cause the acceleration of peak acceleration and response spectrum acceleration in the upper plate,but it will hardly affect the earthquake in the lower plate,and the overhang effect will increase with the decrease of fault dip angle.(3)Elasto-plastic acceleration spectra and elasto-plastic displacement spectra of isolated structures with different fault parameters were calculated using the single-mass isolation model,and the acceleration spectra of the isolated structures,such as magnitude,fault dip,and buried depth of the fault,were analyzed.The influence of displacement spectrum,the study found that with the increase of magnitude,the spectrum acceleration and spectrum displacement of the upper and lower plates of the isolation structure are gradually increased;the increase of the fault inclination angle will gradually reduce the spectrum acceleration and spectrum displacement of the upper plate,but The spectral acceleration and spectrum displacement of the lower panel have almost no influence;the influence of the buried depth of the upper boundary of the fault on the spectral acceleration and spectral shift is more complicated.(4)Isolation design of different periodic structures of the design,and study the horizontal seismic isolation coefficient and displacement of the seismic isolation layer of fault-isolated structures with different magnitude,dip angle and buried depth Influencing laws,the study found that as the magnitude increases,the horizontal damping coefficients of the upper and lower frames of the frame-shear structure gradually decrease.As the fault inclination angle increases,the basic period of the isolation structure increases,and the magnitude-to-horizontal damping coefficient The smaller the degree of influence.The displacement of the seismic isolation layer of the structure shows a gradually increasing trend at the same fault distance,and the displacement of the isolation layer shows an increasing trend along with the decrease of the absolute value of the fault distance.