Study On Seismic Performance Test And Bearing Capacity Of Earthquake-damaged Frame Structure Strengthened By RC-autoclaved Aerated Concrete Block Wall

With the frequent earthquake in china this year, study on the overall seismic reinforcement problem for the frame structure due to damage by earthquake has been importance research topic in structural engineering field. Based on the previous research about RC-aerated concrete block composite wall(grid wall), the overall seismic reinforcement method for earthquake-damaged frame structure using grid wall is proposed. Based on the experiment, numerical simulation and theory analysis, this thesis studied the strengthening effects、mechanical performance、damage mechanism and bearing capacity calculation method by grid wall, the detailed works are as following.(1) By performing the low frequency cyclic loading tests on the half scaled model of empty frame、grid wall、earthquake-damaged frame structure strengthened by grid wall、earthquake-damaged grid wall strengthened by replace aerated concrete blocks, the seismic behavior indexes about damage model and damage mechanism、hysteretic behavior、bearing capacity、stiffness degradation law、deformation、energy dissipation capacity of each specimen. In addition, the strengthening effect and seismic performance of the earthquake-damaged frame structure strengthened by grid wall were also studied. The experimental results show that: earthquake-damaged frame structure by grid wall can improve bearing capacity、stiffness、ductility and energy dissipation capacity, but reduce deformation capacity; earthquake-damaged grid wall strengthened by replace aerated concrete blocks can improve bearing capacity、ductility deformation capacity. Overall the two kinds of reinforcement method can meet the requirements of strengthening.(2) Based on experiment, by the finite element model of strengthening structures, created by the ABAQUS software, the simulation results of stress distribution, carried out the numerical simulation based on the change of key parameters to comparative analysis of different stiffened-cylindrical、aerated concrete blocks strength、axial load ratio etc parameters effect on seismic behavior of the earthquake-damaged frame structure strengthened by grid wall. the corresponding damage index and damage reduction factor is obtained. Numerical simulation analysis show that:improve with different stiffened-cylindrical, but also to improve the bearing capacity; improve with aerated concrete blocks strength, but also to improve the bearing capacity; improve with axial load ratio, but also to improve the bearing capacity, but when axial load ratio is too large, it will reduce the bearing capacity.(3) By damage analysis of earthquake-damaged frame, established the damage model and from damage index get damage reduction factor, the factor used to quantify the bearing capacity decrease after the seismic action. Based on experiment, established a new divide standard of damage grade of the frame structure, the corresponding damage index and damage reduction factor is obtained. Which providing a reference for the damage grade of earthquake-damaged frame and bearing capacity earthquake-damaged frame strengthened by grid wall.(4) Based on experiment and numerical simulation, integrate with damage grade of earthquake-damaged frame, established the bearing capacity of earthquake-damaged frame strengthened by grid wall. Respectively: normal section bearing capacity formula; improve the horizontal weak-layer failure criteria, established calculation formula of shear bearing capacity for earthquake-damaged frame strengthened by grid wall based on horizontal weak-layer failure criteria. Which providing a reference for reinforcing engineering the actual project.