Study On Seismic Behavior Of Prefabricated Concrete Stairs With Sliding Bearings

In the building structure,the staircase plays a role in connecting vertical traffic to the upper and lower floors.According to the survey data of major earthquakes,the damage of the staircase in many reinforced concrete frame structures is very serious,even before the main structure is damaged,causing many people to escape.The passage was cut off and injured.With the rapid development of the construction industry,the deficiencies in the traditional staircase design have been repeatedly highlighted during the earthquake.In recent years,the construction industry is undergoing industrial technological transformation,and prefabricated concrete buildings have begun to glow with new vitality.The industrialization of stairs has a very important role in promoting the development of modern building industrialization.Prefabricated reinforced concrete staircase is just one way of staircase industrialization.The sliding support can be used to disengage the stair plate from the main structure,and a slight displacement can be generated between the components during an earthquake,thereby ensuring that the stair components will not adversely affect the main structure.At present,there are very few studies on the seismic performance of prefabricated prefabricated stairs,so the related research on prefabricated prefabricated concrete stairs is very urgent.In this paper,SAP2000 finite element software is used to establish 5 kinds of three-dimensional models of assembled lower sliding concrete stairs,cast-in-situ lower sliding stairs,fabricated upper-sliding concrete stairs,cast-in-situ upper sliding stairs,and traditional cast-in-situ stairs The model is added to the same frame structure,and the modal analysis of the frame structure model is performed to analyze the influence of different stairs on the frame structure and compared with the frame structure without stairs.Nonlinear time-history analysis of rare earthquakes in different forms of staircase models.Two natural earthquake waves,Elcentro seismic wave and Taft seismic wave,and one artificial simulated seismic wave were input respectively.The internal force and deformation values are compared and analyzed,the distribution of internal force and deformation cloud is analyzed,and the sliding performance of the sliding support is analyzed,and the difference between the sliding support at the upper end of the ladder plate and the sliding support at the lower end is compared.Define the same non-linear time-history conditions,only change the direction of earthquake action,and change the lateral earthquake to longitudinal earthquake.Input three identical seismic wave curves,and compare and analyze the simulated values of earthquake action in two different directions,including the comparative analysis of the internal force anddeformation of the component,and the sliding performance difference of the sliding support.The results show that: The sliding support has good sliding performance,and the sliding support does not fall off and excessive vertical lifting displacement.The comprehensive analysis of the effects of lateral and longitudinal earthquakes provides a reference for the future application and development of fabricated sliding bearing stairs.