Research On Optimization Of Seismic Reinforcement Of Existing Masonry Structure Walls

With the advantages of good fire resistance,wide material sources,low cost and convenient construction,masonry structure is commonly used in China’s industrial field and civil construction.However,the seismic performance of masonry structure is generally poor,furthermore,due to its poor integrity and general tensile,bending and shear resistance,it is prone to brittle damage and overall collapse under earthquake action.The enlargement and reconstruction of existing masonry constructions has developed into a significant tendency in the construction industry as a result of the fact that a significant portion of early masonry buildings with seismic design are currently out of compliance with current codes.This paper first analyzes the advantages of reinforcement mesh cement mortar surface reinforcement method,and then selects 45 degree oblique reinforcement mesh cement mortar surface reinforced wall with better seismic performance than traditional orthotropic reinforcement mesh,examines how the seismic performance of a stone wall is affected by the strength,thickness,diameter,and spacing of the reinforcement mesh.examines the masonry wall’s ductility function under different conditions,including shear capacity for bearing,hysteresis curve,skeleton curve,dissipated energy capacity,etc.The following are the main investigation’s findings:(1)Firstly,ABAQUS finite element software is used,integral modeling is selected,and the masonry wall model is established according to the parameters of the test masonry wall,and the damage pattern,hysteresis curve and skeleton curve are compared with the test masonry wall through the simulation data,and it becomes apparent that the damage pattern and the curve development tendency remain essentially the same,the error is within the allowable range,and this supports the accuracy of the masonry wall finite element model.(2)Establish the reinforced finite element masonry wall model,and compare the orthogonal reinforcement mesh with the 45° oblique cross reinforcement mesh under the same parameters,and conclude that the load capacity of the masonry wall is improved by about 10.2% when the reinforcement mesh is changed to 45° oblique cross arrangement compared with the orthogonal arrangement,which verifies that the seismic performance is better than the orthogonal arrangement when the reinforcement mesh is arranged at 45° oblique cross.(3)The seismic performance analysis of the 45° oblique crossed reinforcement mesh by changing parameters showed that: the change in mortar thickness substantially improved the wall’s shear bearing capacity,and as thickness increased,it also enhanced the wall’s ductility and shear bearing capacity;The mortar strength from M7.5 to M10 substantially improved the wall’s shear bearing capacity;the improvement reduced after M10,and the flexibility parameter was not significantly altered;the diameter of the reinforcement was not significantly changed.With the change of mortar strength,the ductility coefficient does not change much;The shear bearing capacity of the wall is also impacted by changes in reinforcement diameter,with 8 reinforcement having greater ductility and energy dissipation capabilities;The wall’s shear bearing capability rises as reinforcement separation is reduced,and the spacing increases more obviously from300 mm to 200 mm,and less when it is 200 mm to 150 mm,and the ductility and energy dissipation are best when the spacing is 200 mm.(4)The factors that influence the breaking and shear bearing capacities of masonry wall pieces have been gathered and investigated,the initial masonry wall the shear bearing the ability formula has been modified,and the proposed calculation for calculating the shear bearing capacity of a cement mortar surface reinforced wall with a 45° oblique cross reinforcement mesh is derived based on the results of the formula computation along with an examination of the numerical simulation results.