The Shake Table Tests Research For Seismic Performance Of Local Reinforcement Strengthening Of Concrete Gravity Type Piers With Low Longitudinal Reinforcement Ratio

The gravity pier with low longitudinal reinforcement ratio concrete is widely used in high-speed railway in China(??0.5%).The damage is between complete brittle failure and ductile failure.The existing research lacks the theory and Research on seismic design of gravity pier system with less reinforcement concrete,and the research on its seismic performance by shaking table test is less.Based on a concrete gravity solid pier with few reinforcements,this paper designs a scale model.Through shaking table test and numerical simulation,the seismic response of reinforcement ratio of 0.3% and two other local reinforcement encryption models are studied.The variation rules of each index of the three models under different peak seismic loads are summarized,and the accuracy of the established numerical model is verified.The following are the main contents of this paper:(1)Reading a lot of documents about gravity piers with few reinforcements,sorting out many existing research conclusions,summarizing the research status at home and abroad,listing the research methods of structural seismic resistance,as well as the requirements of standard seismic fortification objectives and design methods.(2)Based on the similarity theory of model test,this paper takes an existing gravity pier with few reinforcements as a prototype,designs and manufactures a test model with geometric similarity ratio of 1:15 according to the existing conditions of the test,and designs and manufactures two other contrast models of reinforcement infiltration in local plastic hinge area,and conducts shaking table test on them.(3)By shaking table test of the model,the seismic responses of the three models(displacement response,acceleration response,model period and stress response)are measured by inputting different peak acceleration and different types of seismic waves into the model,and the data obtained are evaluated and analyzed.(4)Through the finite element numerical simulation of the model,the seismic response of the model under the same seismic load input and test is calculated,and the conclusions are compared with the experimental results to verify the accuracy of the model results.In this paper,the seismic performance of gravity concrete piers with few reinforcements for high-speed railway is studied.On this basis,two contrast models of local reinforcement strengthening in plastic hinge area are proposed: model II,local longitudinal reinforcement strengthening in plastic hinge area,and model III,local reinforcement strengthening in plastic hinge area.The test reveals the failure mode of the concrete pier with few Reinforcements under earthquake and evaluates the overall seismic capacity of the structure.In this paper,the seismic response law of Gravity Bridge Pier with less reinforcement and 0.3% reinforcement ratio is summarized.At the same time,the rationality and economy of local reinforcement are verified.