Bearing Capacity Research On Multibarrel Tube-confined Concrete Columns

The recent years, the multibarrel tube-confined concrete columns are applied at the roads and the bridges extensively because of good mechanical performance. The Multibarrel tube-confined concrete columns have superior performance. It has an skeleton effect on the structure. It has many advantages such as: construction conveniently and safely, and provides favorably condition for the bridge construction. It is a development direction that adopts the multibarrel tube-confined concrete columns in the future in order to reinforce the extant concrete filled steel tube columns and to avoid adopting the thick steel in the big columns. At present, the principal sectional forms of the multibarrel tube-confined concrete columns have two types: the circular hollow steel tube both inner and outer and the circular hollow steel tube inner and square hollow steel tube outer. The first one has superior performance because of the even restraint. The last one has the simple section and its joint is easy to treat. The text has an special and finite element research about the above multibarrel tube-confined concrete columns. The solution obtained in this paper and the test results is satisfied.On the one hand, the ultimate load calculation formula for the above multibarrel tube-confined concrete column under axial compressive and eccentric compressive is derived based on the UST (unified strength theory) in the paper and all kinds of factors are analyzed. And the formulas can provide the reference to theoretical research and engineering design. (1) The theory results calculated with the UST are in good agreement with the literature data and it shows that the YU-Maohong UST is feasible for the multibarrel tube-confined concrete column. (2) The between tension and compression strength ratio and the intermediate principal stress have an important effect on the bearing capacity of the composite tube-confined concrete column. The ultimate load is increasing because the tension-compression ratio of the steel is increscent. When the interior friction angle is increasing, coefficient k is increasing and the ultimate load is increscent. From results, we can know that when coefficient...