Research On Construction Control Of Long-Span Concrete Filled Steel Tube Arch Bridge

The concrete-filled steel tubular bowstring arch bridge’s construction supervision andcontrol technology is an important part of the bridge construction technology, and its missionis to predict and control the construction process of the concrete-filled steel tubular bowstringarch bridge so as to ensure that the structure is safe and stable state, and its stress anddeformation is always within within safe level during construction, in order to the final bridgeconforms to design requirements. This paper based on the1-128m concrete-filled steel tubularbowstring arch bridge of double tracking of Lanzhou cross cross Urumqi River. Its researchcontents include construction control method, arch rib assembling technology, stability duringconstruction, optimization of concrete-filled steel tube spouting, cable tension testing.Firstly, this paper reviews the development and research of concrete-filled steel tube andconcrete filled steel tube arch bridges, describes the construction control general situation ofconcrete filled steel tube arch bridges. This paper put the stress, deformation and stabilityduring construction of the bridge as control objectives, and establish the construction controlsystem which is fit to the bridge.Secondly, the finite element model considering construction process is built by usingMIDAS/CIVIL, the model have theoretical analysis on the structure of the main constructionphase of stress, deformation and stability, also research and predict the variation of thestructure in different construction stage. Finally obtain the stability coefficient and bucklingmode of construction in the main construction phase. Using this model, the paper domechanical analysis on different perfusion solutions for the of concrete arch rib.Again, this paper is guided by dynamic construction simulation calculation, use the dataof field test.The paper can do the “dual control” during the construction phase, and provide abasis for construction by coMParing the observational values and the theoretical ones. Usingthe finite element model to optimize the cable force, this paper use frequency method of cabletensioning force early.after adjusting cable tension the cable force reached the designrequirements.Finally, this paper introduces the construction process, the order of installation,equipment selection and stent removal order, and the strength of steel stents based on theUrumqi River Rib assembly construction methods, and calculate the stiffness and stability ofsteel pipe supports. Additionally, it gives the elevation of the main girder of each arch rib andrectificate and adjust constantly during the erection so as to the arch rib can have smoothclosure.