Study On Seismic Performance Of Partially Concrete-filled Eccentric Compression Steel Circular Bridge Piers

Partially filled steel tube structure is a steel pipe partially filled with concrete to bear the load of the building components compression. It can give full play to advantages of steel and concrete materials, and has high carrying capacity, good seismic performance, save steel and highlight the advantages of simple construction and in high-rise buildings, urban bridges; large span structure has been widely used. However, the bridge project in the country, only a few piers use steel concrete structures, partly filled with concrete piers steel structure is rare. This article is based on the study in Japan, the United States and other countries on the part of concrete filled steel piers. Using ABAQUS finite element analysis software, seismic performance analysis was carried out. This analysis adopts Plastic damage constitutive model, and take the restrain effect of steel tube into consideration. As the steel material, we refer to the constitutive relation considering the bauschinger effect under the hysteretic loads.The main work of this paper:First, calculate the height of the eccentric compression steel pier columns partially filled with concrete based on the reasonable height formula in axial compression. Then study the mechanical properties of eccentric partially concrete-filled steel circular cross-section bridge pier and eccentric circular steel pier columns, with the comparison of literature data verified the validity of the finite element analysis.Based on the research on the eccentric partially concrete-filled steel circular cross-section bridge pier and eccentric circular steel pier columns, analysis on 20 bridge pier filled partially with concrete. The contents include mainly hysteretic curve, bearing capacity-displacement curve, rigidity degeneration curve, ductility, energy dissipation and so on. In addition, a parametric research is conducted to study the effect of various parameters such as the eccentricity, radius-thickness ratio and draw ratio on the seismic performance of such piers column. Studies have shown that the ductility of the pier is affected mainly by the eccentricity and slender ratio, while the bearing capacity is affected mainly by the eccentricity and radius-thickness ratio. The ductility increases with the decrease of the slender ratio, while the bearing capacity improves with the decrease of the radius-thickness ratio. Capacity and ductility performance are reduced with the increase of the eccentricity, serious losses when the eccentric rate exceeds 0.3.