Study On Seismic Behavior And Resilience Model Of A New Precast Concrete Wall

With greater importance and promotion attached to housing industrialization, prefabricated concrete structure avoids the shortcoming of traditional construction as it has a high degree of industrialization, fast construction progress, high comprehensive and economic benefit, which is in line with national “low-carbon economy” and “four saving-environmental protection” requirements and avoids the shortcoming of traditional construction. My group organically combines the original ecological composite wall structure principle and prefabricated shear wall structure based on previous research results, then puts forward the new type of precast concrete wall structure system. Considering the difference of arrangement of reinforcement(uniform, field type, shaft type), vertical connection mode(welding connection and pulp) and horizontal connection mode(horse teeth, T slot and rough surface), The author designed 6 1/2 scaled wall(SW1-SW6) artifacts for pseudo-static experiment research; based on different key parameters of new prefabricated concrete wall lateral stiffness, correction formula is proposed; With the consideration of the stiffness degradation of four line, restoring force model is set up.All these will lay a theoretical foundation for the new prefabricated concrete wall structure design method.The ground work as follows:(1)By pseudo static test of new prefabricated concrete wall, the effect of different arrangement of reinforcement(uniform, field type, shaft type), vertical connection mode(welding connection and pulp), horizontal connection mode(horse teeth, T slot and rough surface) and other key parameters on seismic performance of wall are studied. It is showed that if the side wall concrete connection way is the horse teeth, vertical edge artifacts and cast-in-situ wall panel will be in good performance of occlusion. Therefore, in the process of the wall stress and vertical edge components work performance, wallboard is good. Joint only appears minor cracks when it is damaged. If wall and bottom beam vertical connection mode is embedded plate welding, the welding stress in the process of the wall and bottom beam work performance is good. embedded welding plate can not only effectively reinforced vertical stress, at the same time make embedded welding plate welding wall shear resistance superior to the slurry wall connection. The stiffness degradation rule of 6 wall is basically same and the overall trend of attenuation curve is unstable in the early loading. With the increase of displacement, the plastic deformation continuously develops, resulting to the slower and weak stiffness attenuation. The whole stiffness attenuation is evener without obvious stiffness mutation. Embedded welding plate can effectively improve the overall lateral stiffness of the wall.(2)On the basis of above test, and different distribution of reinforcement, the contrastive analysis of the effect of vertical and horizontal connections and other key parameters on lateral stiffness of new type precast concrete wall is carried out. Based on ABAQUS nonlinear numerical model, multiple combination of concrete, steel and pulp layer, and the contact element to simulate the horizontal precast concrete wall panel with cast-in-place edge constraint level boundary connection between components is established, and welding plate and mortar layer in the vertical direction in the bottom of the wallboard boundary is fixed. Through numerical extension analysis, the effect of the reinforcement ratio of edge constraint component, axial compression ratio, the wall height to width ratio and weld position and quantity on the lateral stiffness of new type prefabricated concrete wall is discussed. At last, the new correction formula of lateral stiffness of new type precast concrete wall is proposed via regression analysis of key parameters. Test results and calculation results shows that the correction formula of lateral stiffness match test results well, which can meet the needs of the actual engineering calculation.(3)Through the analysis and calculation of experimental data, analysis formula skeleton curve of new type of precast concrete wall is raised.The standard lag circle of the yield point and peak load point of the wall and stiffness degradation law of each stage after walls crack and restoring force path are determined. Combined with the feature of new type precast concrete wall, macro finite model of shear wall is improved. The spring axis axial stiffness and shear stiffness of shear spring are determined to establish multi-vertical-line-element model of new type precast concrete wall. The wall body skeleton curve is calculated and then compared with experimental results and skeleton curve of degenerate four linear restoring force model theory. Test results and calculation results shows that the degradation of more than four linear restoring force model and the improved multi-vertical-line-element model describing the new prefabricated concrete wall seismic behavior is of high accuracy, which can meet the demand of practical engineering calculation.