Abstract:To study the impact of bridge construction on adjacent subway tunnel structures, taking a footbridge project as the background, and through three-dimension numerical simulation and calculation, the variation law of the structural displacement of the adjacent metro tunnel under the conditions of segmental hoisting of the superstructure and different construction sequences throughout the bridge construction process is analyzed. The results indicate that the horizontal displacement of the existing subway tunnel structure caused by adjacent bridge construction is significantly greater than the vertical displacement. The construction scheme of segmental hoisting of the superstructure is used able to effectively reduce the impact on the existing adjacent tunnel structure. Both the horizontal and vertical displacements of the tunnel can be controlled within the 10 mm warning value specified in the code, and when the beam section close to the tunnel side is implemented first, the displacement value of the tunnel structure is the smallest. Based on the analysis results, it is proposed to adopt the full-sleeve rotary drilling rig for pile foundation construction. The beam section structure close to the tunnel side is firstly implemented. During the construction period, the engineering suggestions are provided for effectively controlling the displacement of tunnel structures, such as strengthening the monitoring of horizontal displacement of tunnel structures, which provides the theoretical basis and engineering reference for the subsequent design, construction and monitoring of similar bridges adjacent to railways.
