Stress Analysis And Improvement Measures Of 0~# Block In Long Span PC Continuous Rigid Frame Bridge

Long span PC continuous rigid frame bridge have been widely used as a bridge type with its superior performance, mature construction techniques and the all terrain suitability. But with the construction and use of more and more of the same kind of bridge, various problems of continuous rigid frame bridge are also gradually highlighted, especially the crack problem of 0~# block in bridge, should attracts more attention.This paper was based on Hongyanxi Large Bridge which is located at Long Yong high speed eleventh section in Hunan Xiangxi, referring to the analysis of construction and design of similar bridges before, in the light of 0~# block construction process of rigid frame bridge, calculating the stress of the structure and analysing the possible position of the crack.By reading and referring to the relevant literature at home and a broad and the results of previous analysis, this paper carried out the experiments of mechanical properties of the new silicon polypropylene fiber concrete material which was used in this project, and put forward the effect of concrete mix ratio. Then the principles of the nonlinear analysis of concrete shrinkage and hydration heat were introduced.In combination with the casting condition of 0~# block in the actual construction process and the stress state of 0~# block in the whole bridge analysis of MIDAS software, using ANSYS finite element software to analyze the local stress of 0~# block. Analyzing the principal tensile stress of the structure in terms of sunlight temperature, shrinkage, hydration heat and so on, as well as principal compressive stress and deformation. Comparing the stress distribution trend with relevant literature analysis and simulation test results to demonstrate the reliability of finite element analysis, pointing out the position and main influencing factors of the cracks in the casting process of 0~# block.Finally, according to the main influencing factors, the corresponding structure improvement plans were proposed to reduce the effect of hydration heat, shrinkage, and sunlight temperature on 0~# block, putting forword some optimization measures in construction process to prevent temperature cracks in the casting process of 0~# block.