Analysis Of Mechanical Characteristics Of Long-span Rigid Frame Arch Bridge Under Heavy-duty Railway Loads

Continuous rigid frame beam arch combination system bridge is a new type of competitive bridge type,combining all the advantages of continuous rigid frame and arch bridge,clear transmission force,light structure,and more and more applications in railway system engineering.This paper takes the Ganjiang Bridge in Ji’an on the Menghua Railway as the engineering background,and comprehensively analyzes the stress characteristics,displacement changes and stability of the bridge during construction and operation.Mainly do the following work:(1)The overall description of the generation,classification,stress characteristics,construction methods of the continuous rigid frame beam arch combination system and the application scenarios of such bridges at home and abroad.(2)The finite element calculation model of the full bridge was established by the large-scale bridge special software Midas/Civil combined with the design drawings and construction organization design.(3)Calculate the stress strain and internal force of the main component beam body,concrete-filled steel tube arch rib and boom under different load combinations during the construction phase and the bridge operation phase.Checked by current specifications,strength and stiffness meet the requirements.(4)Using the general finite element software Midas / Civil,the stability and safety of the bridge under the most working conditions during the construction phase and the most unfavorable load conditions during the bridge operation phase are calculated and analyzed.The instability modal diagram is output and the critical load is calculated.coefficient.And compared with the current specifications,stability meets the requirements.