Seismic Fragility Analysis Of Precast Shear Wall Structure With IDA Methodology

In recent years,China is vigorously developing industrialization of buildings.As a large number of urban residential buildings adopt shear wall structure,the assembled concrete shear wall structure system is currently being widely studied and applied.The seismic performance is the main factor affecting the promotion of the fabricated shear wall structure.The current research mainly focuses on the assembled shear wall joints,while the research on the seismic performance of the assembled integral structure is less,and the whole research on seismic performance of structures is mostly based on deterministic analysis.The randomness of ground motion and the uncertainty of structural parameters of fabricated shear wall members under construction adverse factors are not considered.The results are difficult to comprehensively determine the seismic performance of the structure.In this paper,the ABAQUS finite element software is used to analyze the influence of various structural parameters on the mechanical behavior of the prefabricated concrete shear wall.Based on the analysis of 30 fabricated shear wall samples,the comparison with the cast-in-place level is given.The ratio of stiffness reduction and bearing capacity reduction is obtained.Incremental dynamic analysis and fragility analysis of a 27-story cast-in-situ shear wall structure and a 17-story,27-story,37-story fabricated shear wall structure were carried out by using MIDAS / GEN software.Here are some valuable results.(1)In the finite element software ABAQUS,the finite element calculation results are in good agreement with the experimental results through the reasonable setting of the material parameters and interface contact of the model,which indicates that the numerical simulation is a kind of effective method for the analysis of assembled shear wall.Based on the numerical simulation results,the parametric analysis was carried out,and the effects of structural parameters such as axial compression ratio,longitudinal steel bar diameter,interface friction coefficient and wall thickness on the mechanical behavior of the fabricated shear wall were obtained.(2)Superimposing the various influencing parameters of the structure to characterize the uncertainty of the seismic performance of the structure itself.Based on the analysis of 30 fabricated shear wall samples,the calculation results of the stiffness bearing capacity of each sample model are extracted.The stiffness bearing capacity of the finite element model of the cast-in-place shear wall is compared.The ratio of the stiffness reduction ratio and the bearing capacity reduction of the assembled shear wall is given statistically.It is the macroscopic finite element of the overall structure of the fabricated shear wall modeling provides a simplified basis.(3)The seismic demand analysis based on incremental dynamic analysis is carried out on the three structural models,and the relationship between the ground motion intensity parameters and the structural seismic demand parameters is obtained,and combined with the set shear wall structure performance level.The values of the seismic vulnerability curves of the structure are plotted.The results show that under the 7-degree rare earthquake design acceleration,the probability of collapse of the 27-story fabricated shear wall structure under earthquake action is 4.6%,which is higher than The collapse probability of the 27-story cast-in-situ structure is 3.2%,and the assembled shear structure with 17 layers is 0.02% under the 7-degree rare earthquake,which is lower than the 27-layer assembly.The probability of collapse of the shear wall structure.To this end,this study suggests that the height of the structure should be strictly controlled during the design of the fabricated structure to prevent it from adversely affecting the seismic performance of the structure.At the same time,in the process of construction of the fabricated structure,especially the joints must be well connected.To reduce the defects caused by construction,so as to reduce the probability of collapse or serious damage of the assembled structure in the earthquake.