Research On The Elastoplastic Floor Design Response Spectrum Of Isolated Structures

Non-structural components and equipment in the structure are often damaged under earthquake,threatening the functions of buildings.Isolation technology is an effective measure to improve the seismic performance and resilience of structures.Analyzing the floor acceleration response characteristics of isolated structures and establishing the floor acceleration design response spectrum are of great significance for guiding the seismic design of non-structural components and equipment in isolated structures and ensuring the postearthquake functions of isolated buildings.Based on the actual engineering isolated frame and frame shear wall structures,this paper designs a series of analysis cases considering the influence of different floor numbers,different yield ratios and pulse-like near-fault ground motions.The elastoplastic time history analysis reveals the floor acceleration response spectrum characteristics of the isolated structures,and establishes the floor acceleration design response spectrum of isolated structures.Based on this,a seismic design method of non-structural components is suggested.The main research work and conclusions are as follows :(1)The floor acceleration response characteristics and floor acceleration response spectrum characteristics of isolated structures are studied.Based on 6 actual isolated structure cases,24 analysis cases were designed by considering the 2 superstructure systems of frame and frame-shear wall,different floor numbers and 4 yield ratios.The effects of different types of ground motions(pulse-like and ordinary)were introduced,and a total of 3336 cases were carried out.The elastoplastic time history analysis reveals the floor acceleration response characteristics and floor acceleration response spectrum characteristics of isolated frame and frame-shear wall structures,and analyzes the influence of floor number,floor relative height,yield ratio and ground motion type on floor acceleration response spectrum.(2)The floor acceleration design response spectrum of isolated structures is proposed.Based on 3336 groups of floor acceleration response spectrum data obtained by elastoplastic time history analysis,according to the characteristics of the floor acceleration response spectrum of isolated structures,The 6-segment standardized floor acceleration response spectrum form is adopted.Aiming at the Seismic design requirements of the non-structural components with unclear floors,the acceleration envelope design response spectrum of the isolated structures is fitted,the relative coefficient can reach 0.78-1.00 and biased towards safety.Aiming at the seismic design requirements of the non-structural components on known floor,the acceleration design response spectrum of each floor of the isolated structure is fitted,the relative coefficient can reach 0.72-1.00 and biased towards safety.A method for determining the dynamic amplification factor of the isolated structures is proposed,the relative coefficient can reach 0.92-0.98 and biased towards safety.(3)The seismic design method of non-structural components of isolated structures is suggested.Based on the proposed floor acceleration design response spectrum and floor dynamic amplification factor determination method,a seismic design method of nonstructural components of isolated structures is suggested,and the design cases of isolated frame and frame shear wall are given.The floor acceleration design spectrum and the seismic design method of non-structural components proposed in this study are verified.