The Seismic Performance Study Of High-strength Reinforced Concrete Piers Based On Push-over

According to the statistics, the economic losses are relatively huge which are caused by the secondary disasters due to bridge damage in earthquakes. As the main load-bearing component of bridge, the seismic performance of the pier directly determines the damage or collapse of the whole bridge. In order to enhance the seismic capacity of piers and reduce the seismic losses, the seismic performance of high-strength reinforced concrete piers is researched in this dissertation systemicly, aiming to get the reasonable quantity and arrangement of high-strength reinforcing steel bars and ordinary ones in seismic-type piers, and provide a basis for further comprehensive studing on seismic performance of piers.Based on the summary of relevant theories and methods at home and broad, the experiment study of two HRB400reinforced concrete pier models under compressing-bending load are conducted firstly. The failure pattern of the two pier models, the forces of the steel bars, the load-displacement curve of the pier top and its characteristic point values are analyzed. And the seismic performance of the piers is assessed by capacity spectrum method. Secondly, the nonlinear finite element program ABQUAS is employed to simulate the tested piers and the parameter sensitivity are analyzed. The simulation results are compared with the tested ones. In the premise that the two results corresponding with each other,9models with different reinforcement arrangement are simulated by Push-over method using ABAQUS program. The influence factors on seismic performance of pier such as high-strength reinforcement ratio, high-strength steel bars arrangement, stirrup space and strength, seismic intensity and site classification are studied systematically.The follow conclusions can be drawn from the study. The destruction of the tested piers showed a typical bending failure mode which was caused by the longitudinal tensile steel bars failure and the compression failure of concrete. The nonlinear behavior of reinforced concrete piers can be simulated effectively by choosing reasonable simulating parameters when using ABAQUS program. The high-strength reinforcement ratio, seismic intensity and site classification have great influence on the damage degree of piers in earthquake. There should not be too many high-strength longitudinal steel bars in piers. In the case of same amount of high-strength longitudinal steel bars, the piers will present better seismic performance with high-strength steel bars in the centre of bearing force side than in the corner location.