Seismic Damage Simulation Of Buildings On A Regional Scale Considering Site-City Interaction Effects

Earthquakes may cause severe building damage,and further bring kinds of secondary disasters.Thus,seismic damage simulation of buildings on a regional scale is of great scientific and engineering significance to urban seismic disaster prevention and loss assessment.With regard to two critical issues in regional seismic damage simulation of buildings,i.e.(1)building input motion determination,and(2)parameter-induced uncertainty of building models,following works are performed:(1)Based on the nonlinear multiple-degree-of-freedom(MDOF)model and the open source program SPEED,a numerical coupling scheme for nonlinear time history analysis of buildings on a regional scale considering site-city interaction(SCI)effects is proposed.The accuracy and reliability of the proposed numerical scheme is firstly validated through existing shaking table test data.Then,a case study of SCI effects in a 3D basin is performed to illustrate the applicability of the proposed numerical scheme in real scenarios.(2)Seven sets of shaking table tests on SCI effects are designed and conducted.The tests focus on the influence by terrains,number of buildings,building frequency,and seismic wave input.Through the data analysis,the SCI effects on ground motions and dynamic behavior of buildings under different terrains,are discussed.The shaking table test results are further applied to the validation of the proposed numerical scheme in this work.(3)Based on idealized building configurations,324 sets of cases on nonlinear time history analysis of buildings considering SCI effects are conducted.The case study has considered the influence on SCI effects by the number of buildings,building separations,building height,and seismic wave inputs.The possible variation of peak ground acceleration and peak inter-story drift raio of buildings is discussed,and the characteristics of SCI effects are further illustrated.(4)Based on the real scenarios of Beijing CBD,Shanghai CBD,and a complex terrain area in Hong Kong,the seismic damage simulation of buildings considering SCI effects are conducted.The frequency ratio between the subsoil and the building is pointed out as the best index to correlate with the SCI effects on the building dynamic response variation.Subsequently,the building response variation ranges are concluded with formulas,which are proved applicable through a series of cases.(5)With regard to the parameter-induced uncertainty problems of nonlinear MDOF building models,critical parameters of each structural type are firstly determined based on a large number of collected experimental and analysis data.Subsequently,the parametric sensitivity analysis on reinforced masonry structures and tall buildings is performed.During the analysis,the first-order second-moment method and Monte Carlo method are both adopted to illustrate the characteristics of parameter-induced uncertainty.The analysis results show the controllability of the parameter-induced uncertainty of building models.(6)Seismic damage simulations of buildings for Tsinghua campus,Beijing's second administrative center,and new Beichuan County are conducted,considering both the SCI effects and the building parameter uncertainty.The applications illustrate the scientific and engineering value of the proposed numerical scheme in this work.