Quasi-static Test Study On Railway Gravity Pier Strengthened With Steel Mesh

The railway gravity bridge pier is widely used in the railway line in our country,because of the long construction time and the improvement of the current seismic fortification standard,many of the railway piers which have been built for a long time have not met the current seismic requirements,so it is necessary to study the reinforcement of these existing piers which have not enough seismic fortification capacity.Based on the summary of the traditional reinforcement methods of piers,this paper proposes a new reinforcement method of railway gravity type piers.According to the railway gravity type solid piers,and through the scale model,using the method of combination of quasi-static test and numerical simulation,and by comparing the hysteretic curve,skeleton curve,Energy consumption capacity and Stiffness degradation,summed up and explore the three models of the changes in the indicators of the pier to explore the reinforcement effect of the reinforced grid reinforcement of railway gravity piers,and through numerical simulation to verify the reinforcement effect of the reinforced grid.The following is the main research content of this paper:(1)Through reading a large number of papers about the reinforcement of concrete piers with less reinforcement,this paper summarizes the development process and current situation of seismic reinforcement technology at home and abroad,summarizes and enumerates the advantages and disadvantages of existing reinforcement technology at home and abroad,and puts forward the reinforcement capacity and reinforcement objectives of new reinforcement methods according to the advantages and disadvantages of existing reinforcement technology.(2)Based on the summary of traditional reinforcement technology,this paper puts forward a new reinforcement method of railway Gravity Bridge Pier by using reinforcement grid,introduces the layout of reinforcement,the connection between reinforcement grid and bridge pier,the design and calculation of reinforcement height,the selection of reinforcement materials and the working mechanism of reinforcement grid under earthquake.(3)Based on the design of general drawing of Gravity Bridge Pier of 16 m simple supported beam bridge as the prototype,and according to the conditions of test site and capital,the model scale ratio is 1:8.Based on this,three models of railway Gravity Bridge Pier with less reinforcement are made,and two of them are reinforced with steel grid.After the model is made,the installation,debugging and data collection of quasi-static test equipment are completed Installation test of the equipment and loading production of the quasi-static test.(4)Through the quasi-static test of the model,the test phenomena of the unreinforced model and the two reinforced models under different loading systems are recorded respectively.After the test,the test data are processed and analyzed,and the hysteretic curve,skeleton curve and energy consumption capacity of the unreinforced model and the two reinforced models are obtained,which are compared with the results of the quasi-static test According to the research,the reinforcement effect of reinforcing railway Gravity Bridge Pier with steel grid is studied.(5)The finite element software OPENSEES is used to calculate the model,and the seismic response of the unreinforced model and the reinforced model under the same loading system is obtained.The conclusion is compared with the quasi-static test results to verify the accuracy of the test model results.At the same time,the pushover analysis method is used to calculate and evaluate the reinforcement effect of the reinforcement grid on the piers.The research results of this paper show that the strength,bearing capacity,ultimate displacement and energy consumption capacity of the test pieces have been improved after the reinforcement by the new reinforcement method of steel grid,and the railway gravity piers strengthened by steel grid show good seismic performance,which shows that the reinforcement by steel grid is an effective reinforcement method.The existing piers are strengthened by steel grid The grid reinforcement can meet the requirements of the current seismic code,and has good economic and social benefits.