| As the operation time increases,bridges on existing railway lines are affected by various natural disasters and adverse factors,resulting in various diseases.In severe cases,the beam body needs to be replaced to ensure normal operation of the line.The conventional method of replacing beams on existing lines has limited applicability in the face of special conditions such as high piers,deep water,and canyons.Therefore,this thesis studies a new technical solution for the entire hole transportation and replacement of small and medium-sized concrete T-beams on existing lines,as well as the supporting equipment for the entire hole transportation and replacement of T-beams.The newly developed integrated machine for transporting and replacing full span Tbeams has the function of independently completing the transportation and replacement of concrete T-beams with spans of 12 meters and below on existing lines,as well as independently completing the transportation and installation of emergency repair steel beams with spans of 16 meters and below.At present,there is a lack of research on the structural design and related mechanical analysis of the T-beam whole hole transportation and replacement frame integrated machine on existing lines both domestically and internationally.This thesis conducts the following research work on the new integrated machine for whole hole operation and replacement:(1)This thesis elaborates on the new construction technology for the entire hole transportation and replacement frame on the existing railway T-beam line,as well as the overall plan for the integrated machine equipment of the entire hole transportation and replacement frame.It analyzes and optimizes the construction environment adaptability,adaptability and effectiveness of the existing railway line.(2)Establish the finite element model of the whole machine,determine the load combination according to different working conditions,conduct statics performance analysis,and check the calculation results with reference to the relevant specifications.According to the situation that does not meet the specifications,put forward a plan to add complementary plates on the upper and lower flanges of the double ear main beam based on the SGTJ180 bridge erecting machine.(3)A transient dynamic analysis was conducted based on the process of replacing the frame beam of the integrated machine,and the mechanical response of each structure of the machine was studied.Analyzed and summarized the mechanical response of key sections of each structure and the changes in axle load of the bogie during the process of replacing the frame beam.(4)Based on the load characteristics of the integrated machine for transporting and replacing beams located on flat and straight lines,curved sections,and longitudinal slope sections,the mechanical behavior analysis of each structure during beam transportation and beam replacement operations was conducted.(5)A local modeling was conducted on the main beam and support leg positions of the integrated transportation and replacement machine,and the stress and buckling stability at local positions were analyzed when operating on straight lines and curved sections with a radius of 300 meters.Through the research of this thesis,the structural settings of the integrated machine for transportation and replacement were optimized,and the mechanical behavior changes of the machine under different working conditions were mastered.The stress characteristics of the entire machine during operation in different line environments were summarized.This provides a technical solution and equipment with strong adaptability,high safety,and low cost for the replacement of small and mediumsized T-beams on existing lines in the future,which is of great significance for improving the technical level of railway transportation security in China. |
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