Studies On Alignment Control And Measures Of Super Long-span Concrete-filled Steel Tube

Large span concrete filled steel tube arch bridge usually adopts the suspensionbuckle hang rope hoisting construction, which process is longer, and the stiffness isalso gradually increased along with the construction process. Therefore the progressneed to be controlled accurately. Taking Hejiang Yangtze river bridge as theengineering background, the following problems need to be studied：calculationmethod of cable hoisting system、 the arch rib hoisting cable hoisting system linearcontrol method、 the arch rib closed linear control、hanging buckle system, sealingline of concrete analysis、 phase analysis、lattice girder hoisting phase analysis. Mainworks are as follow:①In the arch rib hoisting phase, the installation of the arch rib alignment has agreat influence on subsequent construction, the arch rib reasonable installation oflinear control methods need to be studied. Of existing linear control methods arecompared and summarized, the linear control method is proposed combined with thecharacteristic of this program. Cable hoisting system of main cable is the mainbearing components, the traditional calculation of cable hoisting system usually adoptapproximate equations to calculate. By analyzing the cable mechanical characteristics,the finite element method of cable hoisting system was calculated, and comparedanalyses the difference between approximate equation and finite element calculationresults.②The arch rib, in front of the closed structure at the largest cantilever structure,is under the most unfavorable condition. Arch rib should be avoided in a bad state fora long time, and the solution of the single rib arch rib fold is put forward, and studiedthe solutions. In front of the strengthening rib and the cable hanger forces have adirect impact on arch rib reasonable fold line, reasonable fold line of arch rib is afunction of the cable force and closed before determine reasonable fold line of archrib is relatively difficult, through the stress free state method has carried on theanalysis of arch rib before closed state, the arch rib reasonable fold the linear controlmethod is deduced.④Rib arch is under the weight of the buckle to hang in front of the closedsystem, the need to dismantle the guy after folded in arch rib by arch rib. Bycomparing different demolition scheme, the effect of line down the process of arch ribelevation is studied. In concrete perfusion phase, due to the upstream and downstream arch rib concrete arch rib is not completely symmetric construction, has been pouringconcrete arch rib rigidity is bigger, so the concrete arch rib deformation of upstreamand downstream of the inconsistent perfusion stage, through to the concreting processwere analyzed, and the upstream and downstream of the arch rib deformation resultsfor analysis.