The Effect On Bearing Capacity Of Concrete Filled Steel Tubular Member With Initial Stress And Self-stress Under Axial Compression

Concrete-filled steel tube arch bridge has been fast developed, because of large span,high bearing capacity,good fit with foundation,nice shape, easy construction and so on. During a short span of20years, there has more than300different span and different structure system concrete-filled steel tube arch bridges been built.The largest span of the concrete-filled steel tube arch bridges that have been completed is518m-Sichuan Hechuan Changjiang river bridge which show a bright future However,during the construction of the concrete-filled steel tube arch bridges,before the steel tube and concrete composited,the empty steel tube has formed initial stress,which will influence the bearing capacity of the concrete-filled steel tube structure.Enclosed in the steel tube,the concret will shrinkage and creep,which will lead to disengaging when the stress is low.Using the Self-stress of concrete can take advantage of the constraint effect, which can improve the bearing capacity and working performance.In this paper, the Chongqing Municipal Education Science 《The effect on bearing capacity of concrete filled steel tubular member with initial stress and self-stress under axial compression))(contract number KJ120412). Research and study from the initial stress and self-stress under axial compression on bearing capacity of concrete filled steel tubular member.①Study the initial stress of steel and the self-stress concrete simulation methods. Exerted on the pipe were made Uniform load and temperature loads were simulated on the concrete initial stress of steel and concrete from the stress exerted by comparison with the test results, verify the reasonableness of the method.②Study out the different of the initial stress of steel and the self-stress concrete menbers, it establishes solid model of concrete-filled steel tube (CFST) members, it has not been seen that the influence research of concrete-filled steel tube bearing capacity considering Initial stress of steel tube and self-stress of concrete at the same time.③According to the results of numerical analysis, the formula for calculating the bearing capacity of concrete-filled steel tube including the initial stress of steel and the self-stress concrete was fitted.④The article has analysed the influence of the Concrete-filled steel tube bearing capacity by the different concret strength, different steel grade,and steel ratio consider-ing Initial stress of steel tube and self-stress of concrete at the same time.