Study On Simulation Of Damage After Earthquake And Reinforcement Of Masonry Wall Based On Finite Element Method

Masonry structure is one of the most widely used structure form in the history,which accounted for a larger proportion in the industrial and civil buildings especially.Statistics show that there are about 80% masonry structure in the industrial and civil buildings in China.And it also will play an important role in the future.There are many characteristics of masonry structure,such as wide material source,easy materials,convenient construction,without large construction equipment,low cost etc.But as far as the seismic level of masonry structure is concerned,there are some defects and deficiencies in the structure itself.The data of previous earthquake damage survey show that masonry structure is more vulnerable to damage than other structural forms,and the losses after earthquake are also the most serious.The seismic resistance of masonry structure is poor,which is also an important reason for masonry structure to be identified and strengthened.Reinforcement is one of the most popular research fields.At present,there are many researches on seismic strengthening methods,and the development of them has been improved.They can improve the seismic capacity of structures and play a better preventive role.Relatively speaking,there are few studies on the structural rehabilitation after earthquakes.When the structure is damaged and then repaired and strengthened,we usually call it strengthening after earthquake.The house has been devastated by the earthquake,in the reconstruction phase,there are a lot of masonry structure can be restored to a good level that can meet the requirements of specification capacity through certain measures to reinforce and repair structure.This part of the masonry structure by repairing structure can greatly reduce the amount of construction of new homes.However,there are almost no studies on the masonry structure after a certain degree of damage,and it lack of data research support.In this paper,ABAQUS finite element software is used to fine model the masonry wall,and simulate the interaction of mortar layer with viscous interface.Simulating the wall under different damage degree,we get the following conclusions: in the slight damage state,masonry walls suffered less damage,with high seismic capacity;in the medium damage condition,the stiffness of the wall decreased,ultimate bearing capacity and limit displacement decreased,but seismic performance decreased slightly;in the seriously damaged,the rigidity of the wall fell significantly;in the near collapse state,the wall almost completely destroyed,and it does not have the basic seismic capacity.At the same time,the method of life and death element is used to simulate two strengthening methods of cement mortar,steel mesh reinforcement and carbon fiber reinforced composite.The reinforcement analysis is carried out according to four kinds of failure modes,namely slight damage,moderate damage,serious damage and near collapse.Through the extraction and analysis of the hysteretic curves,skeleton curves and damage nephogram,the corresponding reinforcement recovery effects are obtained.By using the method of cement mortar reinforced surface layer reinforcement,significantly improve the bearing capacity and the limit displacement of the wall in the slight damage,moderate damage and serious damage.But in the near collapse form,they can not be restored to the level before the earthquake.By the use of carbon fiber reinforcement method,in the slight and moderate damage,the seismic ability of the wall get better recovery,the seismic levels exceed the original wall.In the severely damaged condition,wall seismic capacity returned to close to the original wall level.But in the near collapse form,seismic performance the wall can not be restored to the original level of the wall.At the same time,this paper compares the reinforcement effect and the cost of reinforcement of the two strengthening methods,and points out that the strengthening of the damaged masonry wall is better than that of the CFRP reinforcement.