The Study For Dynamic Characteristics And Thermal Stress Of Base-isolated System About Overlong Structure

At present,overlong structure is becoming very popular with the constant development of China's economy.By requirement of their functions,expansion and constriction joint is not supposed to be located or at least frequently located in overlong structure.To these overlong concrete seamless structures,its length exceeds the code limits and the stress caused by temperature and shrinkage is rather large,which usually brings crack in structure.Sometimes the crack is so wide that the structure can't be normally used.Study the code for design of the concrete structures,temperature variations are even not taken into consideration in overlong structure.Just only some Construction treatments considered.Therefore,to the overlong concrete seamless structure,the important influences of temperature action on structure are taken into account in structure design.At the same time,our country is a country of many seismic,and seismic zone are widely distributed,Especially May 12,2008 earthquake in Wenchuan,The impact of the earthquake affected more than half of China,resulting in substantial damage to buildings collapsed and serious casualties and property losses.Therefore,in order to resist the seismic protection of people's lives and property safety,seismic has become an urgent and important mission.Many damage and show that the simple use of seismic methods to reduce the seismic hazard is not enough.Therefore base-isolation technology as earthquake prevention and disaster reduction as an effective means at its structure and the actual seismic tests show the good effects of isolation,a simple structure and stable performance in our country have been widely promoted and applied.By referring to the bridge engineering experience,the method of installing the rubber bearing in the concrete frame is put forward to improve the seismic performance of structures, which is a meaningful try on crack control.In this paper,the results of earthquake time history analysis between the base-isolated structure and base-fixed structure are compared,using large-scale finite element analysis software SAP2000 structural dynamic response of elastic-plastic time-history analysis to explore the use of base isolation technology of damping effect.Secondly,from the temperature on the ultra-long structure,the further analysis of overlong structural members at isolated and non-isolated case of thermal stress and deformation results and conducting further analysis and comparison.Author has done much analysis study to the based isolation structure and traditional structure about overlong structure,at one time compared to the structural performance and temperature stress between the base isolation structure and aseismatic structure.The base-isolated technology is feasible and secure,and even be able to effectively reduce the thermal stress arising from the structure,reducing the size of the temperature effect.