The Stability Analysis Of Long-span Continuous Rigid Frame Bridge's High-pier

In recent years, as China's road transport industry, as well as the rapid development of the western development strategy of further in-depth, high-pier-span continuous rigid frame bridge has also developed rapidly, As the span increases and the bridge piers height increases, the stability of the bridge has become increasingly important.Targeted high-pier structure of the main features of compression of the force can be high pier for the sake of simplifying the overall stability of truss structures similar to the critical load issues. The suspension strut system no more than two types of equilibrium stability: The first branch point of balance between stability and the second extreme point of equilibrium and stability. This article summarizes several methods for solving the critical load and, based on analytic method in the energy method to derive a single variable cross-section of the sloping wall thickness of limb, etc. pier in the weight box similar to the critical load under the action of general formula. Text in order to support projects, for example, through the finite element analysis and derivation of the formula accurately compared to verify the results of the formula are somewhat conservative, but the error is not large, has a certain value engineering.This article relies on the design of the Yunnan Biyun Bridge for single and double limb box high pier in detail the overall stability of a comprehensive comparative analysis. According to the proposed construction and operational phases of the most unfavorable loading conditions, through the Midas software simulation analysis resulted in the most unfavorable high pier buckling stability of the largest cantilever stage of the construction phase. The overall stability of the high-Pier analysis for the various phases of the various loads have carried out detailed analysis and out of each load on the stabilizing influence of high pier size. Analysis taking into account the linear and nonlinear factors, found that ignoring non-linear analysis of the results are often a negative side. Through all stages of the overall stability of the analysis, obtained in the same large-span continuous rigid frame bridge in single-limb box-high pier is usually higher than the pairs of limbs box to better stability of the pier.Finally, the article through the box cross-section of the local high-pier stress analysis, obtained a high pier box often appears in the most disadvantaged section of high pier with the main beam or pile cap joints. In this paper, local stability analysis, by studying the pier top box loads of high stress change on the pier cross-section, obtained cross-section of local buckling of concrete high pier the whole process of change, and by drawing the stress - strain curve is reflected . The stress - strain curve of concrete materials, broadly in line with the theoretical variation of the construction of high-Pier Top load control has a good reference value. At the same time, this specific high-pier after the changes in the thickness of the local stress analysis found that: in the wall thickness is derived within the framework of the theory of change, its high negative cross-section of local stability of the pier with the wall thickness reduction becomes smaller.