Research On The Seismic Performance And Design Method Of The Pbsec Frame Structures

The precast concrete structure is the most often used precast structural system and has the advantages of being environmentally friendly and carbon-free.Compared to the wet connection structure,the dry connection structure merits further investigation and promotion.The construction form and seismic performance of dry connection structures are two major study topics.In large-scale engineering applications,a dry connection structure system with a simple structure and great seismic performance is required.Dry connection structures come in a variety of sophisticated construction forms.Therefore,employing dry-connected precast technology,a precast bolt-connected steel-members end-embedded concrete(PBSEC)connection was designed in this paper.The objective is to simplify the design and construction of the dry connection structure by utilizing the simple and practicable dry connection form of bolt connection and the working principle of the plastic hinge mechanism at the beam ends,so that the dry connection structure can be widely promoted and utilized.This paper,centered on the PBSEC frame structures,starting from the five levels(beamcolumn joint test research,local component and overall structure numerical model,overall structure capacity analysis and evaluation index,overall structure probabilistic seismic performance evaluation,Performance-based design method),analyzed the seismic performance of the new structural system in detail and proposed a numerical analysis model,evaluation index,and design method.The outcomes can serve as a guide for the popularization and implementation of this structural system.The main contents of this paper include the following:(1)Based on dry connection assembly technology,the PBSEC joint was proposed,and a low-cycle reversed load test was conducted to obtain the failure mode,hysteresis curve,and skeleton curve of the assembly concrete joint,stiffness,ductility,deformation capacity,and other test data,as well as further research and verification of the seismic performance of the joint.In addition,based on the residual deformation and degree of damage of the joint,the replaceability of the linked steel plate and the repairability of the joint were assessed.This research can provide a data foundation for numerical modeling and performance evaluation of structural systems.(2)An appropriate numerical model for PBSEC joints was proposed and compared with test results,a simplified and efficient modeling method was provided,and the accuracy of simulation results was discussed.Parameter analysis of joint performance was conducted concurrently by varying the six parameters of precast beam height,precast column height,connecting steel plate position,pin position,column axial pressure ratio,and connecting steel plate thickness.This study can give a modeling foundation for the entire structure’s dynamic analysis.(3)Considering structural uncertainties,a probabilistic technique was developed for assessing the seismic capacity of the PBSEC frame structures.In addition,the probabilistic seismic performance of the PBSEC frame structures with floor slabs and infill walls was investigated in conjunction with the probabilistic seismic capacity analysis technique.A stochastic finite element model accounting for the unpredictability of structural parameters was developed,and the average median value of the damage index corresponding to each limit condition was derived through Pushover analysis.This number can be utilized as a reference index for the evaluation of the seismic capability of the structural system and the seismic design decision-making process.This study can be a foundation for probabilistic earthquake vulnerability analysis and a probabilistic earthquake assessment system.(4)The mechanical model and calculation method for lateral stiffness of the PBSEC frame structures were constructed,and a displacement-based design procedure was proposed.By testing the dynamic response of the structure using a calculation example,the applicability and efficiency of the design technique were determined.This study can give a theoretical foundation for the design of a pre-embedded steel bolted precast concrete structural system.(5)The probabilistic seismic evaluation method for the PBSEC frame structures was established.The probabilistic seismic vulnerability analysis of the structure was performed by considering both the probabilistic seismic capacity analysis of structural uncertainty and the probabilistic seismic demand analysis of ground motion uncertainty.The aseismic performance of the PBSEC frame structures under aftershocks was also discussed while considering the ground motion’s main aftershock sequence.Consequently,the probabilistic seismic performance evaluation method for the PBSEC frame structures was established.This study can be a resource for evaluating and optimizing the structural system’s overall performance.Combined with experimental and computational analysis,the seismic performance of the PBSEC frame structures was analyzed and studied in this work.The structure was thoroughly evaluated with uncertainty,infill wall and floor impacts,and aftershocks.The performance change and development trend were presented,as well as the associated conclusions and reference limitations,giving a theoretical foundation and reference for the popularization and application of the structural system.