The Initial Research On The Seismic Design Of Staircase Of Frame Structure

The reinforced concrete frame structure is a widely used structural form. At the staircase of frame structure, the current designing analytical models for calculation always do not consider staircase components but punch hole in the floor slab of staircase and apply the vertical load of staircase to its surrounding components. However, in previous earthquakes, the researchers discover that in the situation that many main body structures without heavy damage, the staircase structures have been encountered devastative destruction. The staircases which were supposed to play the role to help people escape did not perform their proper functions in face of natural disasters.Owing to the existence of the staircase structure, stiffness of parts of the frame structure is reinforced. Under the earthquake, staircase can absorb earthquake forces to some extend. It is necessary to give systemic analysis and comparison of the force of staircase components and the deformation of the whole frame structure and the difference of the force of its components, such as beam and column with considering the existence of staircase or not under the earthquakes.It designs two representative reinforced concrete frame structures according to codes in this paper. (The model 1 uses to simulate seismic calculation under the condition of punching hole in floor slab of staircase in the frame structure, that is the seismic calculation of the whole structure without considering staircase; the model 2 uses to simulate the seismic design with considering staircase, that is staircase participating the whole seismic design.) And then it comes to the conclusion that it is necessary to take the staircase into consideration in the seismic design of whole structure through calculating and analyzing these models in common and rare earthquakes by using the general structure analysis software SAP2000.The main contents of this paper include:1. To compare deformation of the whole frame structure of these two models under the earthquakes;2. To compare internal force of the components in frame structure of these two models under the earthquakes;3. To analysis the force of the staircase structure's components(step board, landing plate and landing beam of staircase) under the earthquake and compare it with the force without considering the earthquakes;4. To compare and analyze the whole deformation of these two models under rare earthquakes;5. To propose some suggestions on the current design methods of staircase structures and of the staircase-considered overall structures.