Research On Construction Monitoring Technology Of Asymmetric Multi-span Rigid Frame-continuous Composite Beam Bridge

With the rapid development of China's transportation industry,asymmetric multispan rigid-concrete composite beam bridges are increasingly used in bridge design and construction due to their unique properties.The construction of rigid-concrete composite girder bridge itself involves many structural transformations of the structure,and there are many factors affecting the internal force and the shape of the bridge.Unbalanced cantilever construction may also occur under the unsymmetrical span layout.The consideration of these issues is a difficult point in the construction monitoring and analysis work.The paper reviewed a large amount of relevant data,introduced the characteristics of prestressed concrete rigid-concrete-continuous composite girder bridges,elaborated the status quo and development trend of construction monitoring,and established the Liunan expansion and expansion project with a span of 80m+125m+125m+75m.The Luowei Bridge in China is an engineering background.The method for calculating the pre-camber of the main girder is introduced.The influences of factors such as concrete shrinkage and creep,temperature load,concrete parameters,and pre-stress loss calculation parameters on the linear and internal forces of the bridge are analyzed.The susceptibility of the influence of bridge parameters to the calculated parameters of concrete loss and prestress loss is discussed.The influence of these influencing factors on the line shape and internal forces of the bridge is derived.In response to the collapse of the Luowei Bridge,the impact of different closing sequences and temporary consolidation dismantling orders on the bridge construction status was analyzed,and the combination of local geological and hydrological conditions,construction duration,and construction cost proved that the first step was to collapse the intermediate span first.The advantages of dismantling the temporary consolidation scheme after closing and spanning scheme and the middle span are closed.Due to the asymmetrical span arrangement of Luowei Bridge,and there is an unbalanced cantilever construction after dismantling temporary consolidation.In order to balance the stress of the structure during the construction process and adjust the deformation of the bridge during construction,the article uses structural mechanics theory to derive In the process of unbalanced construction of statically indeterminate bridges,the balance formula of the main bridge's rotation angle along the bridge is presented.The rotational stiffness balance method is proposed,and the superiority of this method is verified by engineering examples.The construction of similar bridges provides a theoretical basis.