The Application And Simulation Analysis Of Movable Scaffolding System In The Box Girder Construction Of Railway Passenger Dedicated Lines

Movable Scaffolding System is one kind of large special equipment, and it is used inbox girder cast-in-situ construction. Through the assembly in bridge location and thesupporting of support brackets or bearing platform, the box girder was poured in sitespan by span. Movable Scaffolding System is highly automated, and it makes formwork,support system and via hole as a whole. With the development and progress of MovableScaffolding System construction technology, now it is widely used in road bridge andrailway bridge construction. Movable Scaffolding System is composed of main girdersystem, formwork system,shift system, support system and adjacent structures. It cancomplete a series of construction from mobile scaffold and casting molding to the nextspan construction.Take the DXZ32/900(B) downward Movable Scaffolding System as researchobject. DXZ32/900downward Movable Scaffolding System was designed for the wholebox girder construction of the high-speed railway passenger dedicated line, meanwhileit can satisfy the construction of32-meter span and24-meter span simply supported boxgirder that were cast in place of passenger dedicated line. Introduce the constitution,operating principle and working process of Movable Scaffolding System, and highlightthe preloading test in the process. Preloading test can verify the security of MovableScaffolding System in work condition. The deformation data of Movable ScaffoldingSystem can be got by hierarchical load and unload. Thereby, the arch curve can be obtained throughthe deformation data. Adjust the template in place according to the prestressing camber values tomake the linear of box girders better match design value. The longitudinal anti-capsize, thetransverse anti-capsize,overall stability and local stability were checked. And thestrength and bending performance of main components and main girder and webconnection were calculated.Movable Scaffolding System is non-standard equipment, and its structure iscomplex. Its working condition is complex that bear larger load in construction.Contrast several common box girder production methods. Respectively, analyze theadvantages and disadvantages of each kinds of box girder production method. Highlightthe preponderance and applicability of Movable Scaffolding System compared with theother box girder production method. Contrast the economic indicators of these box girder production methods. Movable Scaffolding System was widely used in passengerdedicated line based on feasibility and economic rationality.According to the characteristics of construction of its own and The construction process,establish the finite element model of support brackets in six kinds of typical workingconditions that are non-load condition and load state of beam by large general finiteelement analysis software ANSYS. Analyze the stress of the whole and part of supportbracket in six working conditions. The calculation results show that support bracketstructure can meet the requirements of strength, stiffness and stability. It can be safelyused in the construction. The dynamic analysis of support brackets that is the mainstress component of MSS was made in addition to static analysis. The dynamic analysisincludes the modal analysis and harmonious response analysis. In the modal analysis,analyze the first30natural frequency. Harmonic response analysis includes three stages.Contrast the harmonic response of different location in the process of via hole. Once thehazardous natural frequency of vibration was determined, identify and grasp the sectionparameter that has larger influence or sensitivity to these frequencies.Establish the whole finite element model of upper bracket in non-load conditionand load state of beam by ANSYS. Analyze the overall stress and vertical deflection ofupper bracket. In low bridge pier construction, support bracket directly support on thebearing platform. In order to guarantee the stability of the support bracket andnon-cracking of bearing platform the load of support bracket, bearing platform needs tobe made level with high grade mortar and locally reinforced. The measure is thatincrease the reinforcement, steel plate if necessary, at contact surface of low bridge pierand support bracket. Because simply supported box girder have two kinds of span:32-meter and24-meter, span change construction is existed. Increase both inside andoutside template and lateral brace to implement the span change construction.Various factors in the site construction were fully considered in the finite elementcalculation of DXZ32/900downward MSS by ANSYS. Calculation and simulationprecision are high. At the same time, it is very useful to the engineering practice.Through the analysis of the support bracket and upper bracket of MSS, results show thatthe MSS can meet the requirements of construction. The finite element analysis of thiskind of MSS can provide reference to solve the practical problems of the similar engineering.