The Tnfluence Of Staircase On Seismic Behavior Of Frame Structure

The staircase is an important part of the multi-storey and high-rise building.The frame structure is a common structure form of multi-high-rise building,which with small stiffness of antagonistic side and the whole structure is softer than other structures.Stairs are common damage parts in earthquake,so the influence of staircase on the seismic behavior of frame is very important.This paper takes a training center project as an example and uses structural design software PKPM for modeling.Then this paper studies and analyzes the impact of stairwells on the overall seismic performance of the frame structure.Then,the influence of stairwells with different layout locations,different forms and different storey heights on the seismic performance of the frame structure is compared and analyzed.Through comparison of natural vibration period,mode of vibration,inter-layer shear,inter-layer displacement and internal force of the frame,the following conclusions are drawn:(1)When the earthquake occurs,the stair space in different positions will affect the overall performance of the building structure.For the concrete frame structure,in the stage of architectural design,the stairwell should be arranged on the periphery of the frame structure as far as possible to reduce the torsional stiffness of the frame structure.However,the stairwell should not be arranged in the outermost position,and the side span should be arranged with the inner span.(2)In the stairwells of different forms,the overall seismic calculation of the structure is the same as that of the total vibration.The translation in the X direction,the translation in the Y direction and the rotation in the Z axis are all the same.After taking part in the overall seismic calculation of the staircase,the overall torsional stiffness of the frame structure increases and the torsional period decreases,so the overall will increase the stiffness of frame.(3)The increase of floor height of frame structure will increase the natural vibration period of frame structure,but it has no effect on the vibration pattern.With the increase of floor height,the maximum node displacement,the average node displacement,the maximum story displacement and the displacement angle of thestructure increase gradually.