Ductility Seismic Analysis Of High-Speed Railway Bridge Piers With Low Reinforcement Ratio

By the stiffness control and other factors,many of our railway bridge pier are used with less reinforced gravity piers,including low-strength high-speed railway bridge pier.These low-strength piers(The reinforcement ratio is less than 0.5%)are difficult to carry out ductile design like road codes or other foreign specifications.On the other hand,due to the large size of the railway bridge piers,the plastic deformation is small even if it is plastic.This means that the low ductility of the railway bridge piercing performance and how the seismic capacity needs to be studied.The main contents of this paper include:(1)Using the finite element analysis software ANSYS,the solid model of the high-speed railway piers was established,and the correctness of the model was verified by the experimental data.The different reinforcement ratio,the stirrup ratio and the piers of the ductility and damage process,and the results were compared.The results show that the hysteresis curve of the piers shows a pinch effect.When the reinforcement ratio is less than 0.3%,the ductility of the pier is poor,and it is brittle.When the reinforcement ratio is more than 0.4%,the pier is good of the ductility performance.(2)The effects of shear span ratio,longitudinal reinforcement ratio and stirrup ratio on ductility index of piers are analyzed.The results show that the reinforcement ratio of the longitudinal reinforcement is the most important factor affecting the ductility of the pier.The increase of the reinforcement ratio of the longitudinal reinforcement can obviously improve the limit displacement and the displacement ductility coefficient of the pier.The hysteretic energy dissipation capacity of the pier can be obviously enhanced,and the speed of the stiffness of the pier can be effectively reduced.The increase of shear span ratio can obviously improve the yield displacement of the pier,and the limit displacement,displacement ductility coefficient and hysteresis energy dissipation capacity of the pier are helpful,but the effect of the reinforcement ratio is obvious.In contrast,the stirrup rate has little effect on the ductility of the piers.(3)The finite element model of a five-span 32m simply supported beam bridge is established by ANSYS,and its dynamic nonlinear time-history analysis is carried out in the vertical bridge.The displacement response of the pier top is obtained under the peak of different seismic waves and different acceleration peaks.The maximum displacement response of the pier top is compared with the ultimate displacement of the pier longitudinal bridge,and the recommended value of the minimum reinforcement ratio of the pier under different acceleration peaks is given.And verify the seismic performance of the existing high-speed railway piers.