Erection And Control Technology Of Girder-Conveying By Trackcable Method For Stiffening Girder Of Long-Span Suspension Bridge In Mountain Area

With the rapid development of the economy and the progress of bridge construction technology, the span of suspension bridges in mountainous areas is increasing constantly. For the purpose of promoting the girder erection efficiency of long-span suspension bridges in mountainous areas, a method was proposed in this study, based on the Aizhai Bridge construction engineering. The feasibility of the method was validated by theoretical analysis, critical structure design and full-scale partial model experiment. The proposed method was finally successfully applied in the construction of the Aizhai Bridge. As a result, the project schedule was greatly shortened as the efficiency increased, which provided a new girder erection method and a new construction control method in suspension bridge construction.A new method-the Girder-Conveying by Track Cable Method (GCTC)-was proposed in this article by exploring methods of stiffening girder erection in suspension bridges and the revelation of an aerial cableway and aerobus transportation system. Following the simulation analysis for the overall push scheme and the single section traction scheme of the GCTC construction process using the finite element method, the single section traction scheme was finally adopted for engineering application in our study. A new method of stiffening girder construction of suspension bridges, called the opportunity hinge method, was proposed at the same time. Based on the project background of the Aizhai Bridge, the construction control schemes were provided by using the opportunity hinge method at the stage of stiffening girder erection and bridge deck installation.The internal force and displacement of the double-layer cable system, which contains the main cable and the track cable, was derived at the initial tensioning and live loading stages using deflection theory. The solution procedure was explained in detail. The influence of the track cable boundary conditions, initial tension and change in temperature on the double-deck cable system was analyzed through numerical examples. It was demonstrated theoretically that the main cable is the bearing structure, while the track cable is the supporting structure in the track cable system. Due to the advantage of large bearing capacity for the main cable and flexible support provided by the track cable, girder erection was achieved safely and efficiently.The structure design of the critical structure track cable, hanging saddle, girder carrier and anchoring system in GCTC was studied. A parameter selection scheme of the critical structure was proposed, with parameters such as material, geometry size and initial tension of the track cable. Meanwhile, the hanging saddle and girder carrier design and optimizing procedure were summarized, proceeding from the design function and requirements. The structure design for engineering applications was introduced. The anchor system of the track cable was designed and studied. The integral incremental launching scheme and single segment traction scheme of GCTC were analyzed, and finally the single segment traction scheme was employed in engineering applications.The integrated design and critical structure design of the full-scale partial model experiment of GCTC were studied, and thus the detailed scheme of structure design for the model was proposed. Furthermore, the experiment model construction and debug test scheme were studied. The feasibility of GCTC system application in engineering was validated by the model test that was conducted.The traction system design in engineering applications was studied. The speed controlling factors in girder traction were analyzed, and the error controlling measure was explored for the synchronous traction of both sides. The construction process in real construction of GCTC was elaborated.