长周期地震动作用下基础隔震结构 抗倾覆能力研究.

In this paper, the seismic response analysis of base-isolated structures with ultimate aspect ratio is carried out to investigate the difference between conventional ground motion and long-period ground motion, and the overturning of base-isolated structures under long-period ground motion is analyzed from the perspective of three parameters leading to structural overturning, namely, isolation displacement, isolation tensile stress, and the overturning moment ratio of the structure. Firstly, nine near-fault impulsive long-period ground motion and nine far-field simple harmonic long-period ground motion are selected. Secondly, the frame seismic isolation structure models are established for three different intensity zones at the limiting height-to-width ratio limits, and the effects of rare earthquakes on the horizontal displacements and axial stresses in the isolation layer of the base isolation structure, as well as the moment ratio of the structure to resist overturning in the case of the rare earthquakes, are analyzed. Finally, the simplified formula of the aspect ratio limit is modified to calculate the theoretical aspect ratio limit under the action of long-period ground motion, and the seismic response analysis is carried out after the structural aspect ratio is modified according to the limit. The results show that, under the action of long-period rare faction ground motion, the displacements of isolation bearings of the base isolation structure generally exceed the permissible limit, and a large number of bearings have tensile stresses, some of which exceed the permissible limit, and the seismic isolation layer is seriously damaged. In a few cases, the structural tilt resistance ratio is less than 1.2, and there is a possibility of structural overturning. Further more, a suggested value of the aspect ratio is given by combining with the simplified formula for the action of long-period ground motion. [ABSTRACT FROM AUTHOR]