Study On The Tension Of The Sling In The Construction Process Of The Long-span Self-anchored Suspension

The self-anchored suspension is a flexible cable combination system bridge which consisted of the main cable and the stiffening beam.It has the mechanical characteristics of both cable and beam. Becase of its good mechanical propertiesan and beautiful and atmospheric modeling,itis been pay much of attention.making the review of the development of the self-anchored suspension bridge, especially introducting its structure and mechanical characteristic.last putting forward to the main research direction of the tension of the sling analysis.the main methods of flexible cable analysis include straight-line method parabola method and catenary method.Catenary method was verified more feasible, Firstly.making the partial derivative to its equilibrium equation to get its flexibility matrix by mathematical analysis method. then getting the cable element tangent stiffness matrix by making the inverse of its flexibility matrix. The geometric nonlinearity of the self-anchored suspension bridge mainly include the cable large displacement effect, the initial internal forces effect, cable sag effect,when almost making accurate nonlinear control analysis.the rational completed bridge analysis can be maked by the section line method and non-linear the precise iterative method, then making reverscalculation to get the empty cable status and determine the empty cable shape and cable saddle pre-offset.at last concluding the method of the tension of the sling and recommending the method of "no stress cable length is control-oriented, cable tension control is supplemented’Finally,taking the actual project as the background,using the theoretical calculation method and nonlinear finite element software Midas/Civil2010to making calculation and analysis to complete the bridge rationally and construction simulation. specially making dynamic process analysis on these critical control factors in the slings,tension (slings,force、extension rod length、separation in the temporary pier and the main beam、longitudinal displacement of the top of the tower, the cables vertical displacement)).To test teh feasibility and effectiveness of the method of "no stress cable length is control-oriented, cable tension control is supplemented ",as wish to help the construction.