Local Stress Analysis Of Steel Box Tied Arch Bridge End Crossbeam

In practical projects,the research of related personnel on local components mainly focuses on the arch bridge foot or the end of the boom,and there are few details on the analysis of the end crossbeam of the tied arch bridge.The end crossbeams are the key local components of this type of bridge.The arch legs,main beams and supports all intersect with the end crossbeams.The forces are complex,and the structure of the end crossbeams themselves is also very complex.Therefore,the end crossbeams are subjected to local force analysis.It is very necessary.This article takes the Xiangjiang River Bridge in Zunyi City of Guizhou Province as the engineering background,uses the finite element software Midas/civil to establish an overall model of the whole bridge,analyzes the construction stage,determines the load conditions in the typical construction stage,and combines the author’s on-site construction monitoring to collect the displacement of the main beam.The data of cross-section strain and cable force were controlled,and the measured values and theoretical values were compared to verify the reliability of the overall model,which laid the foundation for the analysis of the reliability of the end beam’s local force.On the basis of the whole model,the internal force values of the boundary of the section were extracted.A local model of the end crossbeams was established using the large universal finite element software Midas/FEA.The end crossbeam was subjected to a detailed analysis of the typical construction stage and the consideration of moving loads,and the stress distribution of each member of the end crossbeam was clarified.Through the fourth strength theory,the strength properties of the components of the end crossbeam are examined.It was found that the members of the end crossbeam basically meet the strength requirements,and only the stress values of the diaphragms at the individual arch feet exceed the allowable tensile stresses.In order to improve the stress of the diaphragm under the arch foot,the stress value exceeds the allowable tensile stress,the article has made a local area from three aspects: the thickness of the corresponding diaphragm,the number of diaphragm arrangement,the geometry of the diaphragm.The design plan was discussed and specific improvement measures were proposed.The results of this study can provide some reference for the design and construction of this type of bridge.At the same time,it can provide relevant theoretical support for the follow-up structure inspection,maintenance and routine maintenance of the bridge.