Analysis Of Finite Element On Identification And Reinforcement Of A Teaching Building

The construction industry is an important part of Chinese national economy.Since the reform and opening up,a large number of buildings have risen from the ground,and the constructions have suffered from natural disasters and artificial damage during the use,which leads to the inevitable occur of various safety risks.In addition,the requirement of the buildings' safety and stability is becoming higher and higher,and the structural identification and reinforcement become more critical at the same time.The detection,identification and reinforcement of a primary school sports classroom in Inner Mongolia Autonomous Region has been carried out by this paper.The project is a composite structure,and the main structure is a reinforced concrete structure,and the middle hall roof is a flat steel pipe grid structure,which is divided into two parts for test and identification.First,the main structure was tested in seven aspects: foundation,structural system,component layout size inspection,appearance damage,concrete strength,thickness of steel protective layer,carbonization depth and steel bar configuration.According to the test data,the design software is used to check the carrying capacity of the main structure.The results of comprehensive inspection and inspection and the results of bearing capacity identification can be used to grade safetey,and the main structure safety rating is rated as Asu level,which proves that the structure is safe and does not require reinforcement.Second,Six aspects of the structural layout of the steel grid structure,the cross-section,deformation,rust,rod weld quality and appearance coating of grid members,joints,roof panels,etc.were tested.Also,a finite element analysis of the grid of this classroom was conducted with software.According to the calculation results and test data,the bearing capacity of some members does not meet the demand of the current national standard specification,so the safety level of the grid frame is rated as Csu level,and it needs to be strengthened.In this paper,the Casing reinforcement method is used to reinforce the grid frame design,and the load capacity of the reinforced grid frame is analyzed and calculated.At present,the common reinforcement method in engineering is only making the reinforcement to constructions which stress ratio is out of restriction,and without the analyzing and calculating to the reinforced whole constructions.It makes a comparative analysis of the bearing capacity before and after the reinforcement of the grid frame in this paper.The internal force of the adjacent bars will increase when reinforcing the steel pipe by the overlaying of bars,so that the stress ratio of some bars will overrun it's limit after the reinforcement.So that the stress ratio is not over limit part of the bar after reinforcement over limit.Therefore,it is necessary to conduct finite element analysis of the strengthened grid frame.In this paper,it is proposed through the study that not only the bars with stress ratio exceeding the limit are to be reinforced,but also the bigger stress between two adjacent one.Through the analyzing and calculating to this engineering when the stress ratio of bars is greater than 0.76,it considered to take a reinforcement.This project gives a series of precedents for the detection,identified,and reinforcement and research of the grids in the later stage,which has some reference significance for similar engineering practice.