Railway Long-span Continuous Beam-arch Bridge Combining Joint Stress Distribution Rules

On the background of Lanzhou-Chongqing railway Guangyuan Jialing river (82+172+82) m long-span continuous beam-arch combination bridge, the beam-arch joint stress distribution rules of a railway continuous beam-arch bridge has been studied, which the main span is over 150m, the construction and services stages are separated. By taking a finite element analysis which whole first and local second, a whole bridge three-dimensional model has been established. After that, the most typical worst loading cases of beam-arch combining joint construction and services stages have been determined. A detailed finite element model of beam-arch combining site has been established, the stress field distribution rules and its main influencing factors have been investigated, and suggestions about optimization in design are presented. Researches show that, under the typical worst-cases of load, beam-arch combining site has reasonable force, and mainly dominated by longitudinal compression; Stress concentration appears primarily in the support and the corner between the arch foot and No. 0 block with local tensile stress overrun; The tensile stress in the roof and floor is 0.30 similar to 1.27MPa; the contribution rate of secondary dead load, live load and additional force to stress respectively are 22.1%. 23.5% and 11.2%; With regard to large tensile stress area such as the arch foot stiffness transition section and the juncture between skewback and arch springing, strengthening measure such as ease the transition section should be taken.