Study On Seismic Behavior Of Reinforced Concrete Bridge Piers Under Complicated Stress State

The ramp bridges are not the same as the ordinary bridges because of its irregular shape and different bridge pier stiffness. When the irregular ramp bridge is subjected to earthquake action, the bridge consolidated piers are subjected to the coupling effect of compression, bending, shear, torsion, complicated stress state, will cause serious earthquake damage. Because the irregular bridge has an important position in the whole traffic system, and the lack of research on the seismic performance of the consolidated piers, the research on the seismic behavior of the bridge piers has become an urgent task. In this paper, ramp bridge consolidated piers are the research object, and the specific research work includes the following aspects:(1) This paper briefly introduces the current research work on the piers of the ramp bridge and the research status of the seismic performance of the bridge piers,and a research program is made.(2)A total of 4 ramp bridge piers were designed, and the longitudinal reinforcement ratio was 2.3%, and the cross section was 300 mm, which was divided into C group and D group. Group C was studied parameters are stirrup ratio, were 0.6% and 1.5%, dynamic loading system for ±10:±5.D group parameters of slenderness ratio, stirrup ratio is 1.0 %, a pier is a 1.4m,the MTS actuator loading system is ±10:±5, another pier high of 2.4m, loading system is±10:?4.(3) During the experiment, record the pier surface damage phenomenon and crack development, collect displacement and force data by the two MTS actuators, collect bridge pier displacement data by displacement meters and collect material strain data by strain gauges.(4) A systematic analysis of the pseudo static test of 8 pier specimens which is under bending shear and torsion coupling condition is carried out(This paper, 4 pier specimens, the previous 4 completed), and through the failure mode of each pier, the hysteretic curve, skeleton curve, stiffness degradation curve, ductility performance and energy dissipation curve are used to study the seismic behavior of the concrete bridge piers under the complex stress state.(5) Using general finite element software ABAQUS to calculate the skeleton curve is obtained, and compared with the experimental skeleton curve, obtain the basis model of the finite element. And then taking this model as a benchmark, expand parameters analysis.