Study on nonlinear vibration characteristics of the steel-asphalt seismic isolation layer
SHANG Shouping;LIU Shui;College of Civil Engineering, Hunan University;
In order to investigate the material and geometrical nonlinear vibration characteristics of the steel-asphalt seismic isolation layer, shaking table tests were carried out on the steel-asphalt seismic isolation structure, and the isolation performance of the structure under different acceleration amplitudes was analyzed. Meanwhile, on the basis of the stress-strain relationship of steel, considering the second moment effect caused by the vertical force, an algorithm of the skeleton curve of the steel-asphalt seismic isolation layer was proposed. And according to the hysteretic rules of the bilinear restoring force model, a corresponding restoring force model was established. The elastoplastic time history analysis was made by programming with the established restoring force model, and the results were compared with the experimental results. The results are as follows. When the steel bar in the steel-asphalt seismic isolation layer reaches the elastoplastic stage, the isolation layer can absorb most of the seismic energy and significantly decrease the seismic response of the superstructure. The results of elastoplastic time history analysis are in good agreement with the experimental results, and the established restoring force model is accurate and appropriate, it can provide reference for engineering design and nonlinear seismic response analysis of the steel-asphalt seismic isolation layer.