Study On Flexural Behavior Of Out-of-plane Reinforcement Of Strip Stone Wall

Stone is beautiful and generous,which has been widely used in rural areas along Fujian coast.However,the overall performance of stone masonry structure is poor,the flexural capacity outside the plane is weak,and it is easy to collapse under earthquake.In this paper,the common dry masonry slab stone wall in Fujian Province is strengthened by the common reinforcement method of cement mortar surface layer,aiming at the insufficiency of its flexural capacity out of plane,and the following research is carried out.(1)In this paper,nine specimens are tested to study the effect of reinforcement with steel mesh cement mortar on the flexural properties of strip stone walls.The parameters of reinforcement specimens are the reinforcement ratio of vertical steel bars,the thickness of reinforcement surface,the vertical load and the number of reinforcement surface layers.The following conclusions can be drawn: reinforcement with steel mesh cement mortar can increase the out-of-plane flexural strength of strip stone wall by about 1-4 times and the horizontal ultimate displacement by about 2.5 times;increase the vertical reinforcement ratio can increase the out-ofplane flexural capacity of strip stone wall by about 0.7-1.4 times;increase the vertical load can increase the out-of-plane flexural capacity of strip stone wall by about 0.2-0.4 times;The thickness of the layer has little effect on the ultimate flexural capacity of the out-of-plane,but it can improve the out-of-plane flexural stiffness.Increasing the number of reinforcement layers can also improve the out-of-plane flexural rigidity and flexural bearing capacity,but also reduce the out-of-plane horizontal ultimate displacement.(2)The experiment was simulated by finite element software ABAQUS,and the finite element model of Unreinforced and reinforced stone walls was obtained.The results of ultimate load,ultimate displacement,stress distribution and load-displacement curve were obtained by finite element calculation.The simulation results were compared with the test results to verify the rationality of the model.Then the finite element method is used to analyze the parameters.The following results can be obtained: Increasing the distance between steel bar and stone wall can improve the flexural bearing capacity of stone wall;the reinforcement ratio of horizontal steel bar has no effect on the flexural bearing capacity of out-of-plane;under normal circumstances,the compressive zone of masonry mortar is not crushed under the ultimate flexural bearing capacity state,and the strength of mortar has little effect on the flexural bearing capacity.(3)The formulas for calculating the ultimate out-of-plane bending moment of unreinforced,single-sided and double-sided reinforced strip-stone walls are derived.The feasibility of the formula for calculating the ultimate bending moment of strip stone wall is verified by comparing the calculated value with the experimental value.The proposed formula can be used to check out the out-of-plane flexural capacity of reinforced concrete mesh mortar surface.