Seismic Analysis Of Steel Grouted Connecting Precast Shear Wall Structure

The grouted connecting precast shear wall is an important structure type in China’s architecture industrialization process, which has the advantages in properties reliability, standardization, construction speed and economic benefits. But its wildly application was limited by the complex stress distribution on the joint interface and the lack of seismic design method and standard. Based on this situation and based on the aim to promote the application of precast shear wall structure and construction of industrialization in our country better, theoretical analysis, numerical simulation and experimental study methods were used, selecting the grouted connecting precast shear wall which has wild application potential as the research object, according to the interaction distributions on the grouting connected joint interface, to study the mechanical properties, the capacities calculation methods. And afterward, systematic research on numerical simulation approach for solid element joint interface and layer shell element structure, and seismic evaluate approach was researched. After that, according to the contemporary design code and research results of this paper, seismic deign methods and requirements for grouted connecting precast shear wall was discussed. This paper proposed some suggestion on the seismic design of precast shear wall structure, and played as a certain promotion on the development of grouted connecting shear wall technology and the comprehensive application in our country. The main conclusions of this paper are as following:First, according to the mechanical mechanism of the grouted steel sleeve connector, the mechanical mechanism of the improved thin metal pore-forming grouted connector was analyzed using numerical simulation. According to the stress distribution it can be concluded that:the thin metal pore-forming grouted connector achieved a very good connecting properties by utilizing excessive confinement steels and long steel lapping length, without any special manufacture requirements, which proved that this kind of connector has better economic properties.Second, the capacities calculation model for grouted connecting joint interface was proposed which containing four interactions including the dowel shear forces on connecting steel bars, the press and tension force on connecting steel bars, the frictional force and the compression force of the concrete interface. Afterward, by numerical simulation of connecting steel bars’dowel shear stress, the mechanical characteristics of dowel shear stress on differences of tension and compression was obtained. And after that, a simplification was made to simplify the compression and tension different dowel shear stress to unified stress, and based on the simplification, the capacities calculation method for improved thin metal pore-forming grouted connecting shear wall joint interface was proposed. The comparison of the calculation results indicated that this calculation approach is reliable. Apart from that, the shear capacity calculation approach was proposed.Third, by the experimental research of improved thin metal pore-forming grouted connecting shear wall space structure model, the failure mechanism, stress distribution and key mechanical parameters was determined. And the influence rules of interface slip to shear wall mechanical properties was determined. The test results indicated that: 1. the plastic hinge firstly occurred at the ends of coupling beams under cycling load, the precast shear wall element occurred bending-shear cracks, and finally a flexural failure will be occurred at the precast joint interface, and the connection beam is weak. 2. The seismic energy dissipation of the spatial structure model is very good with a low ductility and high capacity.3. Interface slip will reduce the mechanical properties, large slip leading to early crack and yield, which will reduce the energy consume.Fourth, according to the stress distribution characteristics and failure mechanism achieved in the early experimental testes and analysis, the finite element numerical simulation approach for precast joint interface using connection element was proposed. This approach successfully achieved the accurate simulation of the real loading condition using finite element software. Afterward, the stress distribution and concrete damage distribution was studied, which provide a supplementary stress distribution characteristics and failure mechanism and proved supplementary data to the experimental. In the calculation result, the concrete compression damage and tension damage parameter can be used to predict the failure mechanical and crack distribution, which matched the test results perfectly; and the calculation results provide suggestion on finite element simulation of precast joint interface on the shell element shear wall structure.Fifth, according to the data structure of finite element analysis process and the situation of large labor work on structure modeling, the standard layer assembly modeling approach was proposed. Afterward, according to the capacity calculation approach of joint interface and simulation on solid element joint interface, and by using this standard layer assembly modeling approach in the model analysis, pushover analysis and dynamic time-history analysis of the precast concrete shear wall high-rise residential structure in Haimen city, Jiangsu province, the reliability and high efficiency was proved.Sixth, the numerical simulation solution approach for grouted connecting precast shear wall joint in whole structure shell element model was studied and according to the study results, the simulation approach by utilizing a longitudinal reinforcement strength reduction layer to reflect the influence of precast joint interface was proposed. The finite element numerical simulation results show that on the condition of matching the calculation effectiveness and stability, the precast joint simulation method can reflect the reduction effect on the mechanical performance of the whole structure.Seventh, according to the capacity spectrum method and the hysteretic energy dissipation method, the seismic performance of the whole precast shear wall high-rise residential structure was evaluated. Appling the existing seismic evaluation method onto the precast structure considering the reduction of joint interface effect was realized. The evaluation results show that the safety of the precast structure is safe, and its seismic performance matches the requirements. Meanwhile, the parameters calculation method and numerical simulation method used in this paper can provides a very important reference to the subsequent seismic analysis of grouted connecting precast shear wall structure.Finally, according to the current national standard, this paper elaborate the seismic design approach for grouted connecting shear wall structure, and by combining the research results obtained in this paper, some suggestions on vertical and horizontal architectural design, the maximum application altitude, the mechanical calculation, design method for joint interface, construction requirements on precast shear wall and joint interface of precast building was put forward.