Research On The Effect Of Staircases On Seismic Performance Of Frames

At present, stair design, which is without considering the impact of the earthquake, and main body structure design are taken separately. But the frame structure and stair destroyed seriously in the Wenchuan Earthquake. This paper mainly studies the influence of four form staircases on the seismic performance of frames and staircases themselves. And the above models have different layers and different stairwell positions. Therefore, this paper using finite element software for SAP2000established16contrast structure models. Among them, six layers framework model is eight and ten layers framework model is eight. Based on the modal analysis and spectrum analysis, elastic time history analysis and elastic-plastic time history analysis of above mentioned models, this paper contrasted the periods, modal participating mass ratios, inter-story displacement angles, base shears and time history curves of top layer displacement, etc. Based on the above analysis, the paper draws some preliminary conclusions. The influence of stairs to frame structure’s stiffness cannot be ignored under earthquake action. Stairs can increase framework’s integral stiffness; however they may also enlarge the earthquake effect. Enhancement of integral stiffness mainly reflects in the bench plates for direction. Bench plates in frameworks mainly bear axial force. Bench plates which are not considered the impact of the earthquake are unsafe under earthquake action. The final chapter of the paper is some design suggestions for stairs and the deficiencies and prospects.