The distance between east and west towers of Culture Art Center in CBD of Beijing is 36 meters. Three longspan complex spatial staircases with Y-shaped projection are set between the two towers. The overall stiffness of staircases is slender and the mechanical condition is complex. Elastic time-history method was used to analyze vertical seismic acceleration amplification factors of staircases to further understand the seismic features of the structure,and total support reactions were compared using the time-history analysis method,mode decomposition response spectrum method and the vertical seismic action coefficient method. The results show that analysis on contribution of higher mode frequencies by mode decomposition response spectrum method is insufficient and it is easily to lead to small vertical earthquake reaction effect. The vertical seismic action coefficient method cannot distinguish influences of structural dynamic characteristics such as the damping ratio, complexity and constraint condition of the staircase. And time-history analysis method can compensate this deficiency. Effective anti-drop measures were taken in staircase design under the rare earthquakes. Due to the low vertical vibration frequency of the large-span complex spatial staircase, it cannot meet the comfort degree requirements directly. On the basis of the pedestrian vibration analysis,TMD damping technology was adopted on the staircase to control the resonant response of the pedestrian activity and improve comfort degree.
complex spatial staircase
vertical seismic acceleration amplification factor
tuned mass damper