Seismic Performance And Earthquake Damage Model Of High-strength Square Steel Tube Recycled Concrete Short Column

With the deepening of sustainable development strategy,recycling construction waste,alleviating the environmental pollution caused by construction waste and creating green buildings have become one of the hot research issues in the industry.High-strength square steel tube reinforced recycled concrete short columns can not only give full play to the properties of recycled concrete and steel materials,but also greatly improve the mechanical properties of recycled concrete and make up for the defects of recycled concrete.The filling of recycled concrete ensures that the steel will not be unstable and damaged.They interact and complement each other,which not only makes the specimen have good seismic performance,but also provides a new way for the recycling of construction waste.Based on the validation of the nonlinear analysis model,this paper analyzes the high-strength square steel tube reinforced recycled concrete short columns,and designs 24 groups of specimens.The hysteretic performance,skeleton curve and its ductility coefficient,equivalent viscous damping coefficient and stiffness degradation law of the specimens are studied with the replacement rate of recycled concrete,steel ratio,steel tube thickness,axial compression ratio,steel strength and its section form as parameters.The results show that the replacement rate of recycled concrete and the steel strength of section steel have little influence on the seismic performance of the specimen,while the steel ratio of section steel,the steel strength of steel tube,the thickness of steel tube and the axial compression ratio have great influence on the seismic performance of the specimen.The nonlinear analysis results show that the bottom of steel tube is obviously bulging,and the hysteretic curves are all full shuttle-shaped,which has good energy consumption and seismic performance.On the basis of existing seismic performance research and earthquake damage model research,single parameter models based on deformation,energy consumption and two parameter models based on deformation and energy consumption of high-strength square steel tubular steel recycled concrete short columns are established respectively,and linear regression analysis is carried out for energy consumption factors under the two parameter model,and an earthquake damage model suitable for this specimen is established,while the characteristics of the damage model and the influence of different parameters on the damage change process are studied.Among them,steel ratio,steel tube thickness and axial compression ratio have great influence on the damage development law of the specimens,and the research results can provide some reference for the seismic cumulative damage evaluation and analysis of high-strength square steel tubular steel recycled concrete short columns.Finally,using the powerful nonlinear mapping ability of neural network,the nonlinear interaction among steel tube,section steel and recycled concrete is fully considered,and the influence of various parameters on the horizontal ultimate bearing capacity of specimens is comprehensively analyzed.The BP neural network model suitable for the horizontal bearing capacity of high-strength square steel tube section steel recycled concrete short columns and two neural network models based on radial basis function(RBF)are analyzed and compared.The results show that RBF neural network is relatively more accurate in predicting stability and accuracy.Based on the accurate RBF neural network model,the numerical value of damage energy consumption factor is predicted and compared with the experimental data.The results show that the neural network has high accuracy in predicting the horizontal ultimate bearing capacity and energy consumption factor of the specimen,and the effect is ideal.