Evaluation On Seismic Resilience Of RC Frame Structures Strengthened With FRP

Earthquake is one of the frequent and destructive natural disasters.Each earthquake will lead to the destruction of a large number of existing reinforced concrete(RC)frame structures.Such buildings are usually not designed according to the seismic code or based on the design method of bearing capacity or performance,ignoring the resilience of the post-earthquake buildings,resulting in more loss estimates than expected estimates,and the post-earthquake rescue work is difficult.Resilience-based design methods have become a hot topic in recent years,the method of design considering the destruction of structural and non-structural components in the building and the recovery work after the earthquake,it take repair costs,repair time,personnel casualties as quantitative indicators.Because it is not practical to demolish and rebuild a large number of RC structures,it is of great significance to evaluate the seismic resilience of general buildings with reinforcement considering the economic loss factor and the applicability of reinforcement methods.In this paper,using PKPM to design a typical low-rise RC frame structure,the way of fiber reinforced polymer(FRP)reinforcement is modeled by ABAQUS,a large amount of structural results are obtained to compare the changes of the seismic performance with different reinforcement,using the quantitative methods of resilience indicators to evaluate resilience and obtain the optimization of resilience,the main research contents are as follows:(1)Based on the ABAQUS platform,six tests of different FRP-strengthened members and structures are selected for finite element modeling analysis.The simulation results are basically the same as the test results,which verifies the rationality and accuracy of FRP-retrofitted RC frame structure.The above work layed a foundation for subsequent seismic performance analysis of a large number of RC frames with and without FRP.(2)A five-story RC frame structure was designed by PKPM to represent the low-rise RC frame structure.Considering the reinforcement methods of different floors,the performance quantitative indicators of different limit states were selected and determined.The seismic fragility of the RC structure with different FRP reinforcement schemes were anylyzed based on the incremental dynamic analysis method.It is prove that the FRP reinforcement can significantly improve the reliability probability of a serious damage and a collapsed damage,but the reinforcement effect caused by the increase of reinforcement layer is not positively change,and a large number of original engineering demand parameters can be used for resilience evaluation.(3)Referring to the commonly used FEMA P-58 performance evaluation method,the obtained original engineering demand parameters are used to evaluate the resilience indicators of the structure with and without reinforcement.Taking the fortification earthquake and rare earthquake as the typical earthquakes,the comparison and analysis of the resilience indicators with different FRP reinforcement are carried out.The optimization laws of different resilience indicators(repair cost,repair time,casualties)under fortification earthquake and rare earthquake are obtained,and the recommended reinforcement methods in practical application was proposed.(4)According to the latest seismic resilience evaluation standard and supporting evaluation software,the data and information for resilience calculation are input,and the resilience evaluation grade and resilience indicators of the structure with and without reinforcement are analyzed.It is considered that the optimization effect of seismic loss of the reinforced structure is more obvious when encountering rare earthquakes,and the casualties show a regular decrease.