Seismic Resilience Rating And Decision-making Of Uniform Collapse Risk Of RC Frame-shear Wall Structures

Seismic loss of structures is enormous,including the direct loss and the indirect economic losses caused by downtime,casualties and injuries.The structural resilience assessment is also closely related to these three indicators.Therefore,the analysis and evaluation of structural performance indicators is of great practical significance.Avoiding the earthquake collapse of the engineering structure is the most direct and effective measure to mitigate the casualties of earthquake disasters,and is the primary goal of seismic design as well.However,many studies and earthquake damage experience have shown that a unified level of fortification does not mean that the structure has a uniform collapse risk.Therefore,the RC frame-shear wall structure is selected as the research object.Based on the second generation of PBEE research framework,seismic loss analysis,seismic resilience rating and the decision of the uniform risk and risk-targeted four-level fortifications are made for RC frame-shear wall structure.The main research contents are as follows:（1）According to Chinese building norms,five RC frame-shear wall structures with different fortifications are designed in PKPM,and the overall equivalent model of RC frame-shear wall structures are established with OpenSees as the finite element analysis platform.Taking 20 ground motions for 10 times as input,using multi-strip method for probabilistic demand analysis,the overall seismic vulnerability of five different fortified RC frame-shear wall structures is carried out without considering the randomness of the structural fragility analysis,and the component vulnerability grouping of the structure is introduced.（2）Based on the FEMA P-58 full probability theory research framework,the Performance Assessment Calculation Tool,PACT,is used to evaluate the seismic loss of five different RC frame-shear wall structures.And based on the three loss indicators,direct economic loss,repair time,and number of casualties,the intensity-based and time-based performance evaluation of different fortified RC frame-shear wall structures is carried out.（3）Based on The Assessment Standard for Structural Seismic Resilience Rating and the results of loss analysis,the seismic Resilience ratings of five different RC frame-shear wall structures with different fortification intensity were carried out.The seismic Resilience ratings of five different RC frame-shear wall structures under different dangerous sites were carried out.According to the loss analysis,the structural seismic losses under the Chinese current fortification target,50-year exceedance probability of seismic hazard to be 10%,is of significant difference.（4）The monetization of casualties is carried out with LQI（Life Quality Index,LQI）method,concluding that the average life saving cost per capita in 2017 is about 1.79 million in our country.Taking the five fortified RC frame-shear wall structures in the 7-degree anti-hazard area as an example,considering the construction cost,post-earthquake repair cost,and seismic fatality loss during the 50-year design period,the principle of minimum total economic expenditure determines the uniform collapse risk.Then the decision on risk-targeted four fortification levels is made,and the fortification levels are compared with Chinese seismic code and ground motion parameter zoning map.The study found that the seismic loss of the structure with the same anti-collapse capacity increases as the ground motion intensity increases;the seismic loss of the structure under the same ground motion decreases with the increase of the structural fortification level,and the seismic resilience rating gets higher with the increase of the structural fortification level,indicating that the structural modeling,loss assessment and seismic resilience rating methods are correct and reasonable.The loss results of the seismic resilience analysis in different hazard sites show that the generalized risks faced by the structures based on the principle of uniform hazard fortification vary greatly.According to the principle of minimum lifetime seismic risk during the design period,the uniform collapse risk is decided that the annual collapse probability is 5.260×10-5(that is 50-year collapse probability v_fT to be 0.26%).The comparison between the risk-targeted four fortification levels and Chinese seismic code and ground motion parameter zoning map indicates that the decision-making of uniform collapse risk in this paper is reasonable.