水平動と上下動の作用する平面架構のランダム応答

Abstract

The main purpose of this study is to make clear the fundamental characteristics of the three components of near field earthquake ground motions and the general effects of vertical responses on the aseismic safety of structural members of plane frame structures.Statistical properties of the strong earthquake waves recorded in San Fernando Earthquake (1971) and other earthquakes were computed at first. Then the elastic and elasto-plastic earthquake response analysis of the 8-story weak-beam plane frame model subjected to the deterministic ground motions was studied. The results show the maximum responses of frame structures are quite different according to the different frequency characteristics of ground motion. The more general effects of vertical ground motion can be introduced by using the stochastic method. Three types of 3-story weak-beam plane frame models with different span length, subjected to the horizontal and vertical filtered random ground motion, were analysed theoretically and numerically.From this study, the axial force and axial deformation of the column members of lower story, and the bending moment or end rotation of upper beam members increase about 10-20% by considering the vertical earthquake ground motion, than the responses subjected to uni-horizontal motion. Those effects depend upon the vertical frequency characteristics of the structures.