Seismic Response Analysis Of The Multilayer Large Column Net Frame Structure Under The Action Of Vertical Earthquake

The multilayer large column net frame structures have some advantages which are bigger space, flexible decorate and reasonable cost, etc. Therefore it's also used widely in architectural technology developed today, especially as the workshop, the plant, shop which are architectures needing large space. Because of this general structure, quality and rigidity than rules, multilayer frame structures are usually only consider horizontal seismic effects on the structure according to the distribution of seismic code and conventional seismic design principle. But the earthquake damage phenomenon shows, in the high-intensity zones (especially the epicenter), seismic vertical acceleration to buildings and the extent of damage is non-negligible, so it is very necessary to being research about response of the earthquake for big of multi-layer structure column meshes in vertical seismic. Multilayer frame structure of large span column grid is more reasonable and optimization of a seismic design more realistic significance,engineering training center of Xian university of technology (QUJIANG campus), the main building structure is frame structure, four layers,7200mm x7800mm,being typical of multilayer large column net frame structure. The building is damage on some parts in the WENCHUAN earthquake On May 12,2008. By earthquake investigation, the author found that the structure of the top edge across central beam is regularly three vertical cracks, Preliminary analysis is due to the vertical earthquake effect from top to bottom to expand, and function in the longitudinal investigated, one is in its upper parapet pick eaves of vertical seismic action on the swing beam, causing additional deformation cracks., the author dose analysis of earthquake response in vertical seismic about multilayer structure frame column meshes large. Main content as follows:1,Expounded the vertical earthquake damage of structure, and introduced several common calculation method of vertical seismic effects:strikeout decomposition response spectrum method, the elastic-plastic time history analysis, etc.2,Using SAP2000 (the general software of structure analysis) to structure analysis, the dynamic characteristics of structure vibration frequency (or cycle) and vibration model, and analyses the structure stiffness and mass and stiffness of the size distribution of rationality. The analysis of frame concrete structure is using truss model.3,The vertical seismic action of structure of the vibration of the spectrum analysis and elastic-plastic time history analysis, gives structure in the earthquake and severe earthquake structure, and the internal forces and deformations of the structure of vertical seismic action on seismic response and only the horizontal comparison and analysis:frame beams in the vertical earthquake, in vertical displacement is increased, especially in the moment; across the top edge of bending beams increase almost 40%, The vertical earthquake columns axial force on the bending, have certain effect, in the role of column is obvious, the axial forces increased nearly two times.4,the analysis and investigation by the vertical seismic action, visible on the top of the beam. Then, in this paper based on the analysis of SAP2000 selected top side span structure, using large beams for the nonlinear finite element analysis software ANSYS, the stress, displacement etc of beam, also simulated deformation of internal force in the vertical earthquake girder crack of seismic response. At the same time, the calculation results show that in the high-intensity for seismic design of reinforced concrete beams considering across vertical seismic action is reasonable, the whole structure is more safe and reliable.