Study On The Pseudo-static Test Of A New Type Of Railway High Pier Model

In recent years,with the continuous enhancement of China's economy and the increase of railway mileage,infrastructure construction is in full swing.Especially in southwest,northwest and other areas of China,most of them are rivers,mountains,deep valleys and other adverse terrain,so high pier railway bridges are widely used in these areas.At present,hollow section is the main part of high pier bridge,but it is restricted by its large section size and concrete consumption.Based on the high pier structure of Column Slab railway,the research group puts forward a new type of railway high pier,which is mainly composed of concrete pier and steel truss connection system connecting the pier.Through the quasi-static test of the new scale model of railway high pier,the seismic performance and failure mode are explored.Based on the OPENSEES platform,the quasi-static test of the new railway high pier model is simulated,and the numerical simulation method of the new railway high pier structure is proposed.The specific work and research results are as follows:(1)This paper reviews the research on the form of high piers and the earthquake resistance of high piers at home and abroad.This paper focuses on the new forms of high pier structure,and sums up the achievements of domestic and foreign scholars in numerical simulation and experimental research;expounds the necessity of research on the new forms of high pier structure,and analyzes the advantages of using the new high pier structure at present: Based on the concept of rapid replacement and repair after the earthquake,the new high pier structure of railway is designed.(2)The scale model of the new railway high pier is designed and made to explore the mechanical properties of the new railway high pier under the action of reciprocating load.The force displacement hysteretic curve,skeleton curve and stiffness degradation curve of the model pier are obtained through the test.The structural failure process,failure form,hysteretic energy consumption and stiffness degradation are analyzed to explore the seismic performance of the new railway high pier.(3)The failure sequence of the transverse connection system in the new high pier model of railway is explored by arranging the measuring points in each member of the transverse connection system.The most disadvantageous transverse connection system and the most disadvantageous member of each transverse connection system are obtained.(4)Based on the OpenSees platform,the pseudo-static test of the new railway high pier model is simulated.The nonlinear beam column element based on the stiffness method is used to simulate the concrete pier and the transverse connection system.The joint connection element is used to simulate the staggered movement between the transverse connection tie members.The rigid arm is used to simulate the bearing platform,and the data corresponding to the model pier test are obtained.(5)Comparing the data obtained from numerical simulation with the test data,OpenSees platform can simulate the hysteretic curve and skeleton curve of the new type railway high pier quasi-static test very well,and the maximum difference is not more than 10%,which has high precision.