Research On The Overall Incremental Launching Construction Technology Of Steel Box Tied Arch Combination Structure

Due to its beautiful appearance,high material utilization rate,and good overall structural rigidity,beam-arch composite bridges have been widely used in modern bridge construction.However,there are few cases in which the construction of the beam arch composite structure is implemented by the incremental launching method during construction.In this paper,a steel box girder tie arch bridge is used as an engineering support,and the temporary components in the overall pushing construction process of the bridge are analyzed and studied:(1)According to different principles,this article classifies the pushing construction process in detail,introduces the construction principles,advantages and disadvantages of each process,and focuses on the current commonly used pushing methods: drag,wedge,and step.And briefly introduced the temporary facilities in the construction process,and its role in the pushing construction and the problems faced were introduced.(2)Analyze and study the support reaction force of the temporary pier during the pushing construction,compare the measured support reaction force with the theoretical support reaction force,and analyze the vertical reaction force to the pier top by analyzing the elevation error of the temporary pier top.The influence law of structural stress above the pier and the top of the pier are explored to explore a reasonable range of elevation error.(3)The method for determining the orientation,angle and position of the temporary struts between the arches and beams was studied.The method of homogenizing the arch beams was used to convert the fasting beam arch composite structure into a solid belly variable cross-section beam.Under the unfavorable conditions,the temporary struts were set up,a set of temporary struts for the bridge was set up,and the rationality of the setting scheme was verified.The finite element model was established to analyze the temporary support of the project,and compared with the measured values.(4)The girder of composite beam arch bridge was studied and analyzed.Firstly,the influence of the three parameters of guide beam length,stiffness,and unit length weight on the main structure was studied.Then the interaction between parameters was analyzed.The main structure is affected by force.Based on this,based on the project supported by this paper,the optimization values of guide beam parameters are proposed,and the effect of the guide beam and the design guide beam is compared.