Study On The Mechanical Behavior Of Asymmetric Cantilever Perfusion Construction Of Prestressed Concrete Continuous Beam

When the side pier of the continuous beam is high and the cast-in-place section is long,the cast-in-place support can not be used for the construction of the cast-in-place section.Using the bracket construction side across the cast-in-place section will make the side pier bear a great unbalanced bending moment.In view of this special construction conditions,asymmetric cantilever irrigation construction can be used,that is,shorten the side span cast-in-place section,first close the middle span,then the cantilever pouring an unbalanced section,and finally use the construction technology of the bracket construction side cross-cast-in-place section.However,this construction technology is less used than the traditional symmetrical cantilever irrigation construction.Therefore,it is imperative to analyze the mechanical behavior of the structure during the asymmetric cantilever irrigation construction of the continuous beam.This paper to a high-speed railway(48+80+48)m double prestressed concrete continuous beam as the engineering background,established the construction of asymmetric cantilever construction and symmetrical cantilever construction of finite element model,analyze the mechanical behavior of the structure under different construction technology,the main work content is as follows:(1)The prestressed concrete continuous beam proposed in this paper as an example,using BSAS finite element analysis software,the construction of asymmetric cantilever construction and construction,analyze the mechanical behavior of structure in construction and operation process.(2)Based on the analysis of the mechanical behavior of the structure of the two construction processes in different construction stages,it is found that when the asymmetric cantilever irrigation construction is used,the tensile stress beyond the middle and upper edge of the standard limit during the construction of the middle span closure,and the vertical displacement of the structure changes greatly during the construction process.(3)For asymmetric cantilever construction construction structure of tensile stress overrun and vertical displacement change problem,put forward the solutions,in the construction of unbalanced weight measures can effectively solve the problem of the tensile stress overrun,change in the change of temporary consolidation demolition timing,change the size of the weight can effectively solve the vertical displacement changes in the process of construction problem,provide reference for similar projects in the future.