Seismic Fragility Analysis Of Frame-shear Structures Based On New Intensity Measures And CPU Parallel Computing

In 2017,China released the National Seismological Science and Technology Innovation Project,where the resilience of urban and rural region plays an important role.In this context,the seismic performance evaluation of high-rise buildings is particularly important.In addition,the seismic fragility analysis of high-rise buildings is theoretically and practically significant for scientific seismic design and earthquake prevention planning.Therefore,the RC frame-shear wall structure is selected herein as the test bed.Based on the second generation of the PBEE research framework,the seismic fragility analysis of the frame-shear structure is carried out.The main research contents of this paper are as follows:（1）According to Chinese design codes of buildings,five RC frame-shear wall structures are designed as index prototype structures in PKPM,and the nonlinear analysis is carried out.The overall equivalent models of the frame-shear structures are established in the OpenSees platform,which are validated by the available test data.（2）A suite of 99 real ground records are selected as earthquake inputs.Three parameters are used as structural overall response indicator.A total of 35 groups of ground motion intensity measures（IMs）are evaluated from six aspects as efficiency,usefulness,practicability,sufficiency,robustness and seismic hazard computability.A fuzzy comprehensive evaluation method is applied to sort the 35 sets of IMs,then the optimal set of IMs with the fuzzy decision matrix are determined.（3）A new IM,S_{a N},is proposed to be suitable for seismic analysis of middle-rise and high-rise RC frame-shear wall structures.The key parameters of the new IM are determined by the partial least squares method,and the principal component analysis and the validity test are carried out.On the basis of the new IM,S_{a N},with the amplitude and the duration considered,a probabilitic demand model in terms of IM vector is established including the three elements of ground motion.（4）A multi-thread parallel computing program based on CPU is developed for probabilistic seismic demand analysis.Taking frame-shear wall structures as the research objects,different PSDA methods are compared.The PGA and S_{a N} are used as IMs to analyze the seismic fragility of the five index prototype structures,and then analysis results are compared.Based on the cloud-strip method,a cloud-multi-strip method for single and group structures is proposed.The seismic fragility analysis of the group frame-shear wall structure is carried out.The seismic fragility surfaces of the frame-shear structures are constructed by using the vector IM with three-element ground motion information.The results show that the newly proposed IM,S_{a N},proposed is the optimal one under the fuzzy comprehensive evaluation method,and has a good correlation with the structural response parameters with good applicability in seismic performance assessment of frame-shear structures as well.The vector IM based on S_{a N} contains three elements information of ground motion has better goodness of fit,compared with the scalar IM.