The seismic design of staircase in frame structure

As the essential vertical transportation in multistory or high-rise building, stairs is very important. When2008, 5.12Wen-Chuan earthquake occurred, many staircases were seriously damaged especially in the multistory framework structures which were built in recent years. It seems probable that some common fault happened in the design work. In the multistory framework the stairs member may contribute stiffness as a "K"-shaped brace which effecting the deformation of the frame notably, triggering tension or compression to the stairs plate, however, the "K"-shaped brace effecting were neglected in the design courses. This paper analysis the seismic damage of staircase and stairs, puts forward in multistory framework, the design of stairs can choose "rigid" or "flexible" solvent. The suggested methods can be use either to repair the existing stair structure or to design stairs for new frame building in order to improve the structural function of stairs and the overall building.