Seismic Design And Performance Assessment Of Reinforced Concrete Structures Based On Performance Level Ground Motion

The path of the next generation of seismic design theory is performance-based seismic design,which reduces earthquake-related deaths and economic losses by taking life safety and economic loss into account.In many nations’seismic codes nowadays,the fortification level of"little earthquake is not terrible,medium earthquake can be mended,massive earthquake can not fail"is generally used.This design thought has achieved great success in practice.However,this design thought takes the protection of life safety as the main fortification goal,although it can make the main structure of a large earthquake not fail to protect life safety.But it may lead to the loss of normal function of medium and small earthquake structure and cause huge economic loss.Except for very few special structures,most structures are only designed for small earthquake calculation.The lack of quantitative design for medium and large earthquake makes the performance level of the structure difficult to master when it encounters large earthquake of super seismic fortification intensity.In view of the research background and existing problems at the present stage,the main research content of this paper is as follows:(1)A three-level method for selecting performance level ground motion recording is proposed,and a candidate ground motion database is constructed.Based on different seismic fortification intensities and site characteristic periods,the alternative database of ground motion records is constructed from the alternative database.Combined with the nonlinear time-history analysis results of two engineering case structures,the reliability and validity of the ground motion records selected in the alternative database are verified.(2)Study the relevant regulations of seismic normative state level at home and abroad,determine the classification of performance level and quantify the performance level index,give the specific description of the state of performance level structure and the possibility of continued use;Based on the performance level quantization index,the seismic influence coefficient is obtained based on the time-history analysis results of the performance level ground motion input,which can be used as a supplement to the existing seismic action calculation based on intensity.The basic flow of seismic design based on performance level ground motion is given.(3)Deformation of the interlayer In order to calculate the structure’s vertex displacement,the structure’s angle is used as the performance level index.According to the results of different structural modes of nappe,the transformation method of structural nappe curve and S_a-S_d model with single degree of freedom is studied,and the operation flow of obtaining the ground motion peak PGA and spectral acceleration S_a of performance level is given.(4)Elastoplastic time-history analysis of the original structure with multiple degrees of freedom is used in conjunction with the frame and shear wall case study to reveal the function,properties,and probability distribution of performance level ground motion.This technique verifies the accuracy of performance level ground motion.The initial seismic design goal of the structure is verified using the structural time history analysis,which also highlights the structure’s seismic performance when subjected to seismic level motion.