| Earthquakes occur frequently in China and the historical earthquake damage in rural areas is severe.Masonry structure is one of the most important structure types in rural areas of China,its seismic performance is directly related to the safety of people’s lives and property.Therefore,grasping the seismic performance of rural masonry structure,especially old masonry structure,and adopting corresponding countermeasures are effective ways to reduce the influence of earthquake disaster.Thus,based on a large number of field investigation data,the seismic performance status of old masonry structure in rural areas of Jiangxi province are analyzed.In view of the poor seismic performance of local old masonry structure,considering the economic and technical limitations in rural areas and the basis of the previous study,the PP-band reinforcement method is introduced.A series of quasi-static tests and numerical simulation about PP-Band reinforcement were carried out on typical rural brick masonry wall,the main contents include:(1)Conducted field investigation on old masonry structure in rural areas of Jiangxi province,collected a large amount of basic information of local old masonry structure,summarized and analyzed the quality of building materials,structural characteristics and seismic defects,etc.In addition,the vulnerability probability analysis method was used to predict the earthquake damage of local typical masonry structure under the different earthquake intensities.The results showed that the seismic performance of local old masonry structure is generally weak,its material strength and construction quality are also generally poor;the structural components of the most masonry structure are aged to varying degrees and lack of ring beams and structural columns;when the local old masonry structure subjected to the earthquake of the local basic fortification intensity,there are still some houses with severe damage,which indicated that the seismic performance is insufficient to some extent.(2)The quasi-static tests were carried out on four sintered brick walls under different reinforcement conditions.The seismic performance of each specimen was compared and analyzed from the aspects of failure characteristics,peak load,hysteretic curve,skeleton curve,stiffness degradation,etc.The results showed that the PP-band effectively improves the integrity of the wall after cracking.The maximum bearing capacity of the PP-band reinforced specimen is more than 30%higher than that of the specimen without PP-band reinforcement.The maximum ultimate displacement of the PP-band reinforced specimen is twice higher than that of the specimen without PP-band reinforcement,which fully reflects the improving effect of PP-band mesh on seismic performance;high strength plastering mortar can enhance the bonding effect between the PP-band mesh and the wall,which can give full play to the tensile properties of PP-Band.(3)The meso-scale finite element models of the test wall were established,the rationality of the model was verified by comparing the experimental results with the numerical simulation results.On this basis,the influences of the strength and thickness of plastering mortar,the spacing and angle of the PP-band mesh were further discussed.The results showed that the strength of plastering mortar has obvious influence on energy consumption,the hysteresis curve of the model tends to be full with the increase of mortar strength;the thickness of plastering mortar has a great influence on the peak bearing capacity,the peak bearing capacity of the model strengthened by PP-band mesh and plastering mortar with a thickness of 30 mm exceeds 260 k N;the cumulative damage of the model can be reduced by reducing the grid spacing of the PP-band mesh,when the grid spacing is reduced to a certain extent,the improving effect of bearing capacity will be no longer obvious;changing the angle of PP-band mesh has limited influence on the seismic performance of the model. |
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