Contrastive Analysis On Construction Methods Of Bracket And Cantilever Cast-in-place For Continuous Beam With Short And Middle Span About Temporary Structural Stress,Construction Period And Economy

With the development of high-speed railway construction,the research and application of new cradle has also made rapid progress.Because the construction of the prestressed concrete continuous beam by hanging basket cantilever casting method does not affect the traffic under the bridge,the construction method has become the mainstream of the construction of the prestressed concrete continuous beam.However,with the large increase of the number of small and medium span prestressed concrete continuous beams in the high-speed railway,it is necessary to shorten the construction period of the prestressed concrete continuous beam to meet the objectives of the on-line construction and the overall construction period.Requirements make support cast-in-situ construction another choice which can not only meet the construction quality requirements but also effectively solve the construction period and other problems.Therefore,it is necessary to coMPare the advantages and disadvantages of the two construction methods in different environments,including foundation conditions,bridge height and so on.In this paper,the multi-connected medium-sized and small-span prestressed concrete continuous beams in a bid section of Beijing-Shenzhen high-speed railway are taken as the object of study.According to the actual situation of the project,the coMParison and selection of two construction schemes of support cast-in-situ construction and hanging basket cantilever construction are carried out.Meanwhile,the structure and hanging basket model of cast-in-situ support are established by using the finite element calculation software Midas/Civil.According to the requirements of construction specifications,the The weight of support and formwork,loads of constructors and machines,iMPact loads,vibration loads and wind loads during concrete pouring are analyzed for resistance and stiffness.Finally,the two construction schemes are discussed and analyzed in detail from the aspects of process flow,various auxiliary materials used,linear control,construction period and economy,and suggestions for the selection of construction methods are put forward.