| As a kind of relatively mature construction technology,Pushing the construction has been widely used in the erection of the steel box girders for prestressed concrete girder bridge.As a new type of steel composite structure,corrugated steel web composite box girder has built more than 100 seats at home and abroad currently.The choice of bridge and the construction method is many,but in the application of this kind of bridge in jacking construction is not common,the corresponding research is weak,too.In this paper,Shenzhen bridge in Jian in Jiangxi is a bridge crossing the existing railway from Jinggangshan to Jian,the new corrugated steel web-prestressed concrete composite small box girders with a diameter of 21.8 prestressed reinforcement are design and an incremental launching construction scheme with longitudinal and lateral segmental precast erection is put forward.Meanwhile,basing on finite element program of Midas Civil,the whole process of incremental launching construction is analyzed.The achievement can be as a reference by the design and construction of the similar bridges.This paper mainly completed the following several aspects:(1)The development course of jacking construction,mechanical characteristics,and in the use of all kinds of bridge are summarized;Characteristics of corrugated steel web composite girder bridge are introduced,and advantages and development situation at home and abroad,the corrugated steel web using the method of jacking construction advantages and characteristic are summarized.(2)Shenzhen bridge in Jian in Jiangxi is a bridge crossing the existing railway from Jinggangshan to Jian,the new corrugated steel web-prestressed concrete composite small box girders with a diameter of 21.8 prestressed reinforcement are design and an incremental launching construction scheme with longitudinal and lateral segmental precast erection is put forward,the bridge superstructure and infrastructure construction at the same time is implement,greatly improving the construction speed of pusher,shorten construction period.(3)The large-scale finite element Midas/Civil software is used to build the punt construction process analysis model,and the change of the main beam force,the deflection of the guide beam and the structural safety performance during the construction are discussed.The results show that the maximum compressive stress is in the bottom plate,the value is 19.84 MPa,and the maximum shear stress of the web is 79.23 MPa,which satisfies the requirement.Claim.When the leading end of the beam reaches the first temporary pier,the maximum deflection is 172.18 mm,which is about 1/285 of the pushing length(49m).The overall stress analysis of the bridge shows that the maximum compressive stress For the 16.6MPa,web shear stress up to 113.21 MPa,are to meet the regulatory requirements.(3)The finite element method was applied to guide beam stiffness,self-respect and temporary pier location optimization analysis,the results show that the guide beam weight relative to guide beam stiffness are more sensitive,under the condition of satisfying guide beam stiffness,the weight of the nose should try to be reduced.In addition,temporary pier location can effectively reduce the peak and guide beam girder internal force front deflection peak.Under the conditions allow,temporary pier should be set up in the cross location.(4)The finite element model of the full-bridge finite element method of the corrugated steel web is established by means of the finite element program ANSYS.The results show that the top and bottom of the box girder are well maintained,and the maximum negative bending distance and the maximum positive moment are selected.Stress level,and the top plate and the bottom plate maximum compressive stress of 21.6MPa,corrugated steel web maximum shear stress value of 82.5MPa,are to meet the regulatory requirements. |
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