Capacity Study Of Concrete-Filled Steel Box Piers Stiffened With PBL

Because of the advantages on high bearing capacity, fine plasticity and toughness, constructing convenience, good economic performance, Superior seismic performance and so on, concrete-filled steel tubes(CFST) have been widely used in building construction and bridge structures. This paper introduces the state of development and study, the engineering application in continuous rigid frame bridges and existing main calculation methods of the concrete-filled steel tubes at home and abroad. On this basis, this paper completes some study on the calculation methods of the bearing capacity of concrete-filled steel tubes stiffened with PBL. This paper also has drawn some conclusions after the study as follows:(1) The state of development and study of continuous rigid frame bridges and concretefilled tubes is collected and arranged. Some major problems and deficiencies that exist right now also are also pointed out.(2) The research status of the flexural rigidity of concrete-filled steel tubes is arranged, and the calculation methods on flexural rigidity in different relevant specifications at home and abroad are compared and analyzed. A conclusion is drawn that the flexural rigidity of concretefilled steel tubes stiffened with PBL calculated basing on the specification of Eurocode 4 is closest to the experimental value.(3) Mechanism of the composite effect between steel and concrete is stated. Axial compressive bearing capacity of concrete-filled short steel tubes, axial compressive bearing capacity of concrete-filled short steel tubes stiffened with PBL, stability bearing capacity of concrete-filled long steel tubes stiffened with PBL, eccentric compressive bearing capacity of concrete-filled steel tubes stiffened with PBL and bearing capacity of concrete-filled steel tubes in piers are studied gradually. Relevant computational formulas are also derived.(4) Relevant experimental data is collected, and their bearing capacity is computed with the formulas derived in this paper. And then the results are compared with the experimental values, so as to verify the reliability and accuracy of the computing formulas of the bearing capacity that derived in this paper.(5) The computing formulas of the bearing capacity that derived in this paper are applied in actual bridge engineering, and the curve of Axial Force-Bending Moment is provided, which has certain reference significance to the pier design.