| With the development of related technology and theory,the bridge structure is more and more novel,but it also increases the difficulty of construction.This paper relies on the project,using the basket arch and large rise span ratio of the structural form,resulting in a great increase in the difficulty of construction.The construction scheme of the large arch of this bridge is from the initial cable hoisting method to the in-situ support assembly method,and finally the middle arch low-level assembly combined with the overall lifting method.It takes more than one year before and after construction,resulting in a great increase in construction period and cost.Therefore,this paper comprehensively considers the comparative study of various factors to determine the optimal construction scheme.After that,some key problems are studied to ensure the smooth construction process.In this paper,the stability of steel arch bridge must be considered is studied.Firstly,the stability of construction stage is analyzed.Then,by changing the relevant design parameters,the change law of stability of completed bridge stage under dead load is studied.It is hoped that the related research in this paper can provide reference for the design of this kind of bridge and promote the promotion of integral lifting method.The main research contents are as follows:(1)This paper mainly describes the two construction schemes to be proposed later,compares and analyzes the construction methods of large arch from five aspects of construction difficulty,safety,quality,construction period and economy,and determines the best construction scheme of large arch.(2)In the support method construction,combined with the relevant data,through calculation,the reasonable selection of the lifting equipment for the installation of small section arch rib is made.Through the simulation analysis,the structural state of large and small arch during construction is studied,and the stability and bearing capacity of the important components of the water trestle are analyzed.Finally,the unloading process of the middle arch support is studied,and the more accurate jack lifting force is obtained through reasonable constraint replacement.(3)According to the relevant principles of lifting points and structural center of gravity,and considering the weight of lifting objects,the reasonable number and location of lifting points are determined.The force method is used to control the asynchronous effect in the lifting process,and whether this method can reduce the influence of asynchronous effect on the structure is studied,and the failure condition of lifting point is studied.According to the technical specification for integral lifting of heavy structure and equipment,the lifting bracket is checked and calculated,and the structural deformation,stress,bearing capacity and stability of steel pipe pile are analyzed.At the same time,the local model of the arch rib at the lifting point is established,the stress concentration phenomenon at this time is mainly studied,and the improvement measures are proposed to reduce the stress concentration phenomenon of the arch rib here.(4)The stability of lifting arch rib and support structure in construction stage is analyzed,and the linear elastic analysis is carried out in the bridge completion stage.The difference of structural stability coefficient under dead load and dead load + live load is compared,and the influence effect of live load is analyzed.Then,under the dead load,the influence of structural design parameters on the stability of the bridge is studied.Finally,by replacing the suspender with the equivalent node load,the influence of the suspender non conformal force on the structural stability of the arch bridge is studied. |
