Study On The Application Of Isolation Technology In The Reinforcement Of School Buildings

With the development of isolation technology,the application of isolation technology in the reconstruction and reinforcement of existing buildings is more and more extensive.Unlike traditional reinforcement techniques,isolation and reinforcement technology can greatly improve the seismic performance of the original structure on the basis of not reinforcing or less reinforcing the superstructure of the building.Most of the old school buildings in China are brick masonry structures,and their seismic performance is generally inadequate,especially after the 2008 Wenchuan earthquake,China has raised the level of fortification of primary and secondary school buildings(from Class C to Class B),and the application of isolation technology in the reinforcement of school buildings is more urgent.Based on the background of a middle school teaching building in Lanzhou,this paper evaluates its seismic performance according to the test results,and puts forward a scheme to reinforce the teaching building by using isolation technology in view of the serious shortage of seismic performance of the teaching building.The finite element model of the teaching building after isolation and reinforcement is established by using the finite element software SAP2000,and its seismic performance under the multi-encounter earthquake and rare earthquake is studied,and compared with the original structure.At the same time,the construction simulation analysis of the process of converting the original structure system into the isolation system is carried out,and the following conclusions are drawn:(1)Seismic evaluation shows that the seismic performance of a middle school teaching building in Lanzhou is seriously inadequate;(2)The self-vibration period of the structure is greatly increased after the reinforcement,and the first three-order period is more than 6 times times that of the original structure,so that the structural period is far away from the characteristic period of the site;(3)The method of reaction spectrometry shows that the interlayer displacement of the isolation and reinforcement structure decreases greatly,and the interlayer displacement can be kept within the allowable range.(4)Under the action of multiple earthquakes,the interlayer shear Force and acceleration value of the isolation and reinforcement structure are on average 1/3 of the original structure;(5)Under the action of rare earthquake,the response values such as interlayer displacement,top acceleration and interlayer shear force of the isolated reinforced structure are on average 1/5 of the original structure,most of the wall stress is less than the allowable stress,the safety reserve is large,the hysteresis curve of the isolation bearing shows full curve,the support energy consumption accounts for more than 80% of the total energy;(6)in the process of converting the original structure system into the isolation system,the stress of the wall near the replacement beam changes unevenly,which has the characteristics of small wall stress and large ends at the middle of the converter beam span.In the process of removing the bottom wall of the replacement beam,the bending moment value of the beam increases gradually,that is,the negative bending moment of the cross-bending moment and the bearing increase,which conforms to the stress state of the frame beam under the uniform load,and there is a obvious cross-beam effect.