地铁区间隧道下穿国道高架桥的影响分析

Analysis of the Impact of Subway Section Tunnels Undercrossing National Highway Viaduct

基于某新建地铁区间隧道盾构下穿国道高架桥的工程背景,通过三维数值模拟,分析了高架桥在地铁区间隧道盾构下穿过程中的变形和内力,并评估了其对国道高架桥的影响。研究结果表明:在盾构下穿过程中,桥梁墩台及桩基最大竖向变形0.4 mm,最大水平位移2.3 mm。相邻桥梁墩台之间纵向差异沉降控制值0.21 mm,横向差异沉降控制值0.19 mm,均小于对应的控制值。同时,桥梁桩基轴力和顺桥向弯矩小幅增加,但均在桥梁设计预留的安全范围内。因此可以得出结论:该地铁期间隧道盾构下穿具备可实施性。

Based on the engineering background of a newly built subway tunnel under the national highway viaduct,the deformation and internal forces of the viaduct during the shield tunneling process of the subway tunnel was analyzed through three-dimensional numerical simulation,and its impact on the national highway viaduct was evaluated.The research results indicate that during the process of shield tunneling,the maximum vertical deformation of bridge piers and pile foundations is 0.4 mm,and the maximum horizontal displacement is 2.3 mm.The longitudinal differential settlement control value between adjacent bridge piers and abutments is 0.21 mm,and the transverse differential settlement control value is 0.19 mm,both of which are smaller than the corresponding control values.At the same time,the axial force of the bridge pile foundation and the bending moment along the bridge direction increased slightly,but both were within the safety range reserved in the bridge design.Therefore,it can be concluded that the tunnel shield tunneling under the subway during this period is feasible.