Study on Seismic Performance of Circular Steel Piers with Partially Concrete-filled
|School||Shenyang University of construction|
|Keywords||Residual deformation Buckling failure Ductility performance Ultimatestrength Seismic performance|
Considering the different characteristic of steel structure and concrete structure, concrete filled steel tube structure is widely used in construction. This kind of structure lead to an effective performance by the interaction of mutual advantage, hence improve the structure of the overall ability. In domestic pier constructions, only a few of the piers are designed with concrete filled steel tube, and especially rare for some partially concrete filled steel pier. This article adopts ABAQUS finite-element analysis software and gives an analysis on seismic behavior analysis on the basis of partially concrete filled steel pier in the US and Japan. 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.By using the analysis software ABAQUS, the ultimate strength and ductility of circular-section steel tube short column with concrete filled under both axial compression and combined compression and bending are studied. In addition, a parametric research is conducted to study the effect of various parameters such as the radius-thickness ratio, draw ratio, and axial load on the ultimate strength and ductility performance of Short column. Meanwhile, the welding residual deformation is taken into consideration. The design formulas for the ultimate strength, limiting strain and the effective instability length of steel tube with concrete-filled in the pure compression was proposed. This established a theoretical foundation for determining the height of concrete filled. The ultimate strength and ductility performance of steel tube with concrete-filled decreases as the axial load increase in the compression and bending. When the radius-thickness ratio is less than0.1, the mechanical property of short column shows high sensitivity to Rt. Finally, the design formulas for the height of concrete filled is proposed. Through comparing with the test results, and verified the validity of the theoretical formula.Based on the research on the short column, numerical analysis on12bridge pier filled partially with concrete is made in the paper and compared with the experimental results. The comparative contents include mainly deformation trend, hysteretic curve, bearing capacity-displacement curve, rigidity degeneration curve, ductility, energy dissipation and so on. Then the results calculated by the formula of the optimum packing height of the concrete are ascertained whether to match with the range of packing height in the experiment. On the basis of the comparison between the experimental data and analysis results, the structural type of the bridge pier has good ductility so as to reduce efficiently the buckling failure in the tube. The bridge pier in the paper has excellent ability to resist the earthquake in order to improve the defects of the bridge. Owing to parametric analysis on the slender ratio, radius-thickness ratio and so on, the ductility of the pier is affected mainly by the slender ratio, while radius-thickness ratio has a considerable influence on the bearing capacity. The ductility increases with the decrease of the slender ratio, while the bearing capacity improves with the decrease of the radius-thickness ratio.