| Precast structures are in accordance with national strategies in terms of both energy conservation and emission reduction, therefore the precast structure indicates one of the development tendencies for future architectures. By referring to the usual connection type in steel structures, this paper proposes an innovative assembling scheme utilizing high strength bolts and steel connectors to joint precast shear wall panels together, forming an innovative totally precast shear wall structure. In order to perceive the basic mechanical property and seismic behavior of this novel precast shear wall structure, this paper firstly extracts two fundamental connections, namely horizontal connection and vertical connection, from this structure, and then conducts a series of experimental study, numerical simulation, and theoretical analysis on the totally precast shear wall assemblies involving horizontal and vertical connections, respectively. The detailed research contents and results are presented as follows.(1) Experimental investigation on totally precast shear wall involving horizontal connectionFor the sake of different research objectives, two batches of experimental studies are conducted on the totally precast shear walls involving horizontal connection. Firstly, according to the monotonic loading and reversed cyclic loading tests on two specimens of precast shear wall involving horizontal connection, the feasibility and reliability of the bolted connection-based assembling scheme is confirmed, and the seismic performance of the precast shear wall assembly is investigated in terms of the strength, stiffness, ductility, and energy-dissipating capacity, etc. On this basis, monotonic loading tests are performed on three specimens of horizontally-connected precast shear wall with different connection parameters, and then this paper studies the influences of the bolt specification and the flange thickness of the connecting steel frame on the basic mechanical property of the precast shear wall assembly and the stress distribution in the connectors.(2) Nonlinear finite element analysison totally precast shear wall involving horizontal connectionABAQUS software package is adopted to conduct finite element (FE) analysis on the horizontally-connected totally precast shear wall assembly. The simulation results are compared with the test results in terms of the load versus deformation curve and the failure pattern to confirm the reliability and reasonability of the modeling method and parameter setting. Subsequently, a comprehensive parametric study is carried out on the totally precast shear wall involving horizontal connection. The variable parameters cover the bolt specification, mean slip coefficient between the steel connectors, the flange thickness of the connecting steel frame, the intial gap between the steel connectors, axial compression ratio performed on the precast shear wall panel, and connection arrangement. The influence of these parameters on the basic mechanical property of the horizontally-connected shear wall is studied detailedly.(3) Force analysis on totally precast shear wall involving horizontal connectionBased on the experimental research and FE analysis, the working mechanism of the horizontal bolted connection is analyzed. Subsequently, the computational formulae for the characteristic loads (slip load of bolted connection and yield load of connecting steel frame) which related to the horizontal connection are deduced; buckling analysis is conducted on the flange plate comprised in the connecting steel frame; the computational formulae for the characteristic loads (cracking load and yield load) and load bearing capacities (bending strength on the cross section and shearing strength on the inclined section) which related to the precast reinforced concrete shear wall, shearing strength of the horizontal bolted connection, and the deformation capacity (qualitative and quantitative analysis on the constitute of the top displacement) of the horizontally-connected totally precast shear wall assembly are inferred theoretically.(4) Experimental investigation on H-shaped totally precast shear wall involving vertical connectionFor different research objectives, two batches of experimental studies are conducted on the H-shaped totally precast shear walls involving vertical connection. Firstly, according to the reversed cyclic loading test on two specimens of H-shaped vertically-connected precast shear wall, the feasibility and reliability of the proposed vertical bolted connection assembling scheme is confirmed, and the seismic performance of the H-shaped precast shear wall assembly is investigated in terms of the strength, stiffness, ductility, and energy-dissipating capacity, etc. On this basis, the connection details are improved and monotonic loading and reversed cyclic loading tests are performed on four specimens of H-shaped vertically-connected precast shear wall with different connection parameters, and then the the seismic behavior of the improved H-shaped precast shear wall and the influences of the connection parameters on the basic mechanical property of the improved shear wall assembly are investigated in terms of both global behavior (load versus deformation curves, characteristic loads and displacements, strength, stiffness, and ductility) and local reponse (strains in steel bars, strain distribution in the connecting steel frame, and the relative slippage between connectors).(5) Numerical simulation and force analysis on H-shaped totally precast shear wall involving vertical connectionABAQUS software package is used to conduct nonlinear finite element (FE) analysis on the vertically-connected H-shaped precast shear wall assembly. The FE analysis results are compared with the test results in terms of the load versus deformation curve and the failure pattern to confirm the reliability and reasonability of the modeling method and parameter setting, and then the failure mechanism is further studied. Based on the experimental and FE analysis results, several reasonable assumptions are established. Subsequently, the computational formulae for cracking load and yield load of the H-shaped precast shear wall assemblies are deduced; the ultimate shear-resisting mechanism of the H-shaped precast shear wall and the load-transferring mechanism of the vertical connection are analyzed in depth; furthermore, the influences of the improvement measures for connection details on the seismic behavior of the H-shaped precast shear wall are discussed. |
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