Seismic Vulnerability Analysis Of Typical Monolithic Precast Reinforced Concrete Structures

Under the situation of increasing shortage of labor force and excessive consumption of resources and environment,the construction industry urgently needs to transform and upgrade,and the industrialization of construction industry has become the inevitable trend of the development of the industry.At present,the main idea of prefabricated architecture is the concept of "equivalent cast-in-place",and the research is mainly focused on the test and numerical simulation of prefabricated beam-column joint and single prefabricated frame,monolithic prefabricated shear wall and single prefabricated frame-shear wall structure.As an important part of seismic risk analysis,seismic vulnerability analysis of prefabricated structures can predict the probability of failure of prefabricated structures under different levels of earthquakes,which is of great significance for seismic design,reinforcement and maintenance of prefabricated structures.The research on seismic vulnerability of assembled monolithic concrete shear wall structures and assembled monolithic concrete frame-shear wall structures is still insufficient.This paper focuses on four aspects:the contact problem of bonding surface between precast concrete members and post-cast concrete,seismic vulnerability of assembled monolithic reinforced concrete frame structure,seismic vulnerability of assembled monolithic reinforced concrete shear wall structure,and seismic vulnerability of assembled monolithic reinforced concrete frame-shear wall structure.1.The finite-discrete element method is applied to the analysis of prefabricated concrete structures,and the spring failure criterion method is used to simulate the contact failure of the bonding surface between cast concrete and precast concrete members.The rationality of the simulation method is verified by comparing with the experimental results,and the seismic vulnerability analysis of three types of typical prefabricated concrete structures considering the characteristics of prefabricated connections is realized.2.The seismic vulnerability of assembled monolithic reinforced concrete frame structures is studies by using the method of joint refinement and overall large-scale modeling,and the difference between the seismic vulnerability and cast-in-place reinforced concrete frame structures is analyzed.Through the refined numerical simulation of typical beam-column joints of assembled monolithic concrete frames,the difference of plastic hinge location between prefabricated frame and cast-in-place structure is obtained.According to the generalized force-deformation skeleton curve of concrete members in ASCE41-13,the bending moment-angle skeleton curve and cast-in-place skeleton curve models of assembled integral reinforced concrete frame beam-column joints are fitted.Through numerical simulation,the assembled monolithic reinforced concrete frame structure model and the corresponding cast-in-place frame structure model are established respectively,and the incremental dynamic time history analysis is carried out,and the difference of seismic vulnerability between the assembled monolithic reinforced concrete frame structure and cast-in-place frame structure is compared and summarized.3.The seismic vulnerability of the assembled monolithic reinforced concrete shear wall structure is studied by considering the influence of the gaps between the prefabricated shear walls,and the difference between the assembled monolithic reinforced concrete shear wall structure and the cast-in-place reinforced concrete shear wall structure is analyzed.The detailed finite element modeling analysis of cast-in-place shear wall,horizontal slotted prefabricated shear wall,horizontal slotted and vertical slotted prefabricated shear wall is carried out.After verifying the validity of the model,the difference of stiffness and bearing capacity between prefabricated shear wall and cast-in-place shear wall is obtained by comparing and analyzing the characteristics of shear wall under single parameter and double parameter.By comparing and analyzing the performance indexes of cast-in-place shear wall structure under the same conditions,the difference influence law of seismic vulnerability of assembled monolithic reinforced concrete shear wall structure and its corresponding cast-in-place structure is obtained.4.The modified moment-angle model is used in the frame beams and columns,the stiffness and bearing capacity of the shear wall are considered.The seismic vulnerability of the assembled monolithic reinforced concrete frame-shear structure is studied,and the difference between the seismic vulnerability and that of the cast-in-place reinforced concrete frame-shear structure is analyzed.Based on the research of prefabricated frame structure and prefabricated shear wall structure,the numerical model of assembled monolithic concrete frame-shear wall is established,and the seismic vulnerability of assembled monolithic concrete frame-shear wall structure is analyzed.Compared with the corresponding cast-in-place frame-shear wall analysis model,the difference of seismic vulnerability between assembled monolithic reinforced concrete frame-shear wall structure and cast-in-place frame-shear wall structure is revealed.