Experimental Research On Seismic Behavior Of Damaged Masonry Pagoda Walls Strengthened By Grouting And Surrounding-hoop Reinforcement

Masonry pagodas are important part of Chinese ancient civilization, these ancient buildings which are damaged by natural factors and human factors appear different degree of damage. After the "5.12Wenchuan earthquake", we researched earthquake damage of masonry pagodas in high earthquake intensity area, which were damaged mostly by shear fracture. For the destruction of existing masonry pagodas use strengthening single method is insufficient. They need combine two or more composite reinforcements to reinforce these damaged masonry pagodas. At present,"The grouting and surrounding-hoop" composite reinforcement method has become a primary reinforcement method of damaged masonry pagodas after the Wenchuan earthquake. This paper integrated model experiments with computer simulation technology to test the performance and the effect of the strengthening methods, and made theoretical analysis and refining on the test results:(1) We use the holistic model of the brick and mortar to establish the finite element analysis model, simulating loading and boundary conditions of quasi static test. According to the results of solution, the walls mainly appear shear failure pattern. The confining hoop reinforcement’s stress has been in a state of tension throughout the experiment. Along with the increased wall stress the responsibility as the load increases.(2) On the four masonry pagodas model which were damaged by earthquake of using the composite of grouting reinforce and confining hoop reinforcement technique to repair after reinforcement. Respectively through the horizontal low cyclic loading and constant vertical loading test of simulated its seismic performance in the earthquake. The test results show that the energy consumption capacity of specimen after reinforcement, ultimate bearing capacity, ductility coefficient and wall lateral angle are significantly improved. Although this reinforcement can’t improve the wall cracking load, but it can constraint the wall cracks. Use the composite of grouting reinforce and confining hoop reinforcement technique to repair reinforced masonry pagodas are effective and feasible.(3) According to the test results, we provide a shear capacity calculation diagram of earthquake damage of masonry shear wall model by first into structural adhesive to repair cracks, then prestressing steel hoop reinforcement. And proposed the coefficient a of bearing capacity because of the wall body structure is improving by glue joint sealing. Finally forecasts the formula to calculate the shearing resistance of the masonry wall strengthened with composite grouting reinforcement technology.The experimental and theoretical analysis of single-layer brick wall strengthened by the composite of grouting reinforce and confining hoop reinforcement technique show that. The restraint effect of the prestressed confining hoop reinforcement can effectively improve the seismic performance of masonry pagoda. We should research a reinforcement method for multilayer masonry pagoda which was damaged by earthquake:in addition, we also need to explore different prestress level how to improve the seismic performance and the regularity of the pagoda wall.