Research On Main Cable Curve And Suspendertensioning Scheme Of Self-anchored Suspension Bridge

Self-anchored suspension bridge is developed on the basis of suspension bridge,which saves huge anchor and directly to make the main cable anchored in the stiffeningbeam. The span of self-anchored suspension is generally small, because of the structurestress and construction etc, but in recent years, self-anchored suspension has become astrong competitive bridge of City bridge, that is because its layout drawing of bridge typeis flexibility as well as the unique shape.Although early in the19th century has been studied self-anchored suspension, but itwas not until the21st century started to build in our country, and most of them are threespan self-anchored suspension bridge, construction of self-anchored suspension bridgewith single tower is relatively small. Combined with asymmetric self-anchoredsuspension bridge with single tower of Beijing Chaobai River, this paper mainly studiesthe shape of the main cable and suspender tensioning in the following aspects：①Firstsummarizedthesolvingmethodforcablecurveofself-anchoredsuspensionbridge and deduced the formula of main cable shape parabola and catenary, Secondderived the formula for solving the self-anchored suspension bridge main cable shapebased on Lagrange coordinate system, and then write a program to solve final bridge lineand the line in the process of construction of self-anchored suspension bridge.②Through comparativedthedifferences for cableexpressions ofSimplysupported（Consolidation）cable between the bending stiffness cable and the flexible cable knowthat the linear analytic expressions of the bending stiffness cable distinguished fromflexible cable with a polynomial relate to linear influence coefficient(). By analysis thelinear influence coefficient can know, when the tends to infinity, the stiffness cabledegenerates into flexible cable; when the tends to0, the main cable performance for thedeformation characteristics of beams.③Taking Beijing Chaobai River asymmetric single tower self-anchored suspensionbridge as an example, respectively using beam element (Consider the cable bendingstiffness) and Cable element (Ignore the cable bending stiffness) to simulate the maincable of self-anchored suspension bridge, by finite element analysis shows that, with thesling tensioning, vertical displacement between the two main cable is reducing（By the analysis of2can konw the property of main cable bending stiffness is abating along withthe increasing of main cable horizontal component）, and the displacement differencebetween beam and cable is mainly manifested in where the sling is not to be tensioned,and the displacement difference can be neglected when the bridge is completed.④First by analyzing three plans of suspender tensioning of self-anchoredsuspension bridge with single tower shows that, self-anchored suspension bridge withsingle tower suitable for symmetric tension, and using both unstressed length and tensionto control cable tension can make sure safety and efficiency. And then discussed a slingtension method which every slings controlled by unstressed length and only tension onetime, this method is feasible, but slightly sacrifice the safety factor of sling. Finallyexplored a method to adjust cable force of completed bridge based on the influence matrix.