关键词: 地铁盾构, 下穿, 桥梁, 分析, 保护措施

Abstract: The Hefei Metro Line No. 4 crosses beneath the Dangtu Road bridge that carrying the new passenger high-speed railway. The passenger volume of Dangtu road rail bridge is large and the railway operation requires a strictive deformation and stress in the bridge. The influences of deformation and stress in the bridge structure are well analyzed by using the MIDAS GTS commercial finite element analysis software in this paper. The results show that the transverse and longitudinal lateral displacements at the bridge pier are less than 3 mm and the vertical settlement of the pier is less than 5 mm. The differential settlement at the pier is less than 5 mm and the change of the additional stress in the bridge structure is very small. Further, the deformation and stress in the structure meet the relevant requirements. To ensure the safety of the bridge during shielded tunnel excavation, the measures for the safe the construction undercrossing the bridge such as, strengthening the reinforcement strength of shielding segment, separating the undercrossing of left and right lines, strengthening the control of the shielded excavation, are also presented in the paper.

Key words: Metro Shielded Structure, Undercrossing, Railway, Analysis, Safeguard Measures