Analysis The Seismic Performance Of Reinforced Concrete Frame-Shear Wall Structure In Consideration Of The Conditions Of Stairs

Now days reinforced concrete frame-shear wall structure is widely used in tallbuilding structures. The design of stairs is usually separated from the whole frame-shearwall structure, considering the staircase by opening the floor and increasing the load,instead of building the staircase model. However, after summing up the facts of all theprevious seismic data, we find that the staircase which is used as the escape routedestroyed seriously, it even ruined before the whole building. The staircase does notplay its proper function of escape route.After the Wenchuan Earthquake, the revised code for seismic design of buildings(GB50011-2010) has made it clear that: the use of computer analysis of structure,calculation model, the necessary calculation and processing should be consistent withthe structure of the actual condition, and calculation of stair effect should be considered.In frame-shear wall structures, because of the position of staircase, there are someeffects for the rigidity of the whole structure. Using the finite element analysissoftware-ETABS, this article makes a systematic study of the influence of staircase onthe frame-shear wall structure with the method of modal analysis and response spectrumanalysis.In the setting of analysis model, consider the following requirement:1. The number of the rooms;2. The number of the shear wall (Frame bearing seismic overturning moment totaloverturning moment percentage.);3. The position of staircase.Comparing all series of models, we analysis the main effects on the whole structure(self vibration period, floor displacement and angle of floor displacement and so on).The main point lies in the effects to the whole structure by the staircase and to the forceof the stair component under the effect of the earthquake.Here are the main conclusions:Under seismic action, the stairs has some effects on the frame-shear wall structural,including self vibration period, layer displacement, angle of floor displacement and so on, especially in the direction of along the stair. So, in the structure design, we shouldtake the influence of staircase on the whole structure into the consideration.The establishment of staircase has more influence on the internal force, but littleeffect on components which is far away from the staircase. In structural design,attention should be paid to increase the number of reinforcement near the staircase.The results obtained by stair internal components which uses the hand to count ismuch different from that obtained by the finite element analysis software, the originallystairs design method is easy to appear the phenomenon of insufficient reinforcement.Therefore, it is necessary to improve the original design method;The number of shear wall has a certain impact on the analysis results. Shear wallarrangement is more; staircase stiffness of whole structure effects is weaker, especiallyin the staircase near the shear wall arrangement. In practical engineering, designconsiderations should be based on the different circumstances of the staircase.