Seismic damage analysis and design suggestions for staircases in RC frame structures
JIANG Huan-jun1,2, WANG Bin1, LU Xi-lin1,2
1. Research Institute of Structural Engineering and Disaster Reduction, Tongji University, Shanghai 200092, P.R. China;2. State Key laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, P.R. China
Abstract：Staircases, critically important for egress and access during emergency events, suffered severe damages in recent earthquakes at home and abroad in reinforced concrete frame structures. Staircases, acting as the first line of defense in the earthquake, firstly yielded and failed, and were out the action of emergency access, which could not meet the seismic performance objectives. To realize the objective of acting as safe access under strong earthquakes, the current Chinese seismic design code for buildings specifies special requirement on the design of staircase. The comparison of numerical analysis of a typical reinforced concrete frame structure under frequent earthquakes between considering and neglecting the effect of staircases is carried out to study the influence of staircases on the structural behavior. The effect of staircases on the yielding and failure mechanism of the structure is investigated by nonlinear static analysis. Accordingly, the reasons of the damage suffered by the in-situ cast staircase and precast staircase are analyzed. Finally, some suggestions to improve the design of staircases are proposed according to the analytic results and the current design method.
2013, Vol. 32 
