Study On The Influence Of Construction Deviation On The Medium-supported Stiff Skeleton Arch Bridge And Its Countermeasures

The stiff skeleton arch bridges are becoming the preferred type of long-span bridges,because of its beautiful shape,strong spanning ability and good economic benefits.The construction processs of this bridge is complicated and the period is long.During the construction period,the structure undergoes many system changes,and the construction deviation is almost inevitable.In order to accurately analyze the stress state and ensure the safety of the bridge,it is necessary to deeply study the causes of construction deviation and its influence on structural force of the arch bridge structure.Based on the Guangan Guansheng Qujiang Bridge,this paper uses Midas/civil2015 to establish the finite element model of the bridge to study the causes of various construction deviations during the outsourcing construction and the impact on the structural forces.The main research contents and results are as follows:(1)Based on the finite element analysis software Midas/civil 2017,the model of this project is established by discussing the finite element simulation methods and basic assumptions involved such as the order of outsourcing pouring,the change of structure temperature,the change of concrete strength,the shrinkage and creep of concrete,etc.(2)Taking the project as an example,the actual change of arch rib alignment of outsourcing the lower ring and the deviation of arch rib alignment from the calculated value under the comprehensive action of various construction deviations are analyzed in detail.The common construction deviations involved in the relevant specifications in the construction stage,as well as those not covered by the design drawings and specifications,are summarized and analyzed.These construction deviations affect the structure.(3)The finite element software is used to simulate the construction load deviation,asymmetric construction,outsourcing construction scheme deviation,structural temperature deviation and so on.The influence of these construction deviations on the arch rib alignment is studied.(4)By simulating and calculating the loading procedure,the strength deviation and construction loading time deviation,the influence on the stress difference of arch rib and the upper and lower edges of each section is studied.Considering the live load effect and material time-varying effect,the development and creep mode of these deviations under the influence of these factors are obtained.(5)By summarizing the commonly used control measures for outsourcing construction of stiff skeleton arch bridges and combining with the construction deviation of relying projects,the main contents of construction deviation control for such bridges are put forward.Finally,the general rectification measures are applied to relying projects,and the rectification scheme for the construction deviation of this project is given.The research results of this paper have received the attention and recognition of the relevant units of this project,and have made targeted corrective adjustments accordingly...