Research on the Mechanical Properties of Frame Structure Staircase Setting Isolation Bearing

¹ School of Civil Engineering, Chang’an University, Xi’an, Shaanxi, China
² China Northwest Architectural Design and Research Institute, Xi’an, Shaanxi, China

Abstract

First, in order to make the stair be a life channel in the earthquake, the authors set an isolation bearing between the platform beam and stair plate to separate the main structure and the stair. It can avoid the adverse effects on the main structure under the earthquake. Then this paper designs three reinforced concrete frame models: one including stairs, one excluding stairs and one including the stairs with the use of isolation measures. And the authors use the response spectrum method for each model to calculate and analyze, the results show that the staircase had an impact on the lateral stiffness of the structure, and the seismic performance had an obvious difference between the model including stairs and the model excluding stairs. The layout of stairs can change the structure stiffness center, thus affect the torsion effects of the structure. The stairs, the staircase frame column force and the sway were increased and formed the weak parts of force. By setting the isolator to separate stairs with the main structure, the stairwell structural damping ratio is increased, the seismic effects on stair components are effectively reduced, the staircase column internal forces are significantly reduced and they can avoid the staircase column damage occurred under an earthquake. At last, this paper presents a reasonable measure to separate stairs from the overall structure, and a design and calculation method to set isolator in the frame structure staircase. It can make stairs members do not participate in seismic calculations of the overall structure and can effectively avoid the stairs component damage.