厦门轨道交通3号线厦门火车站站暗挖隧道宽34.5 m，高11.7 m，整体下穿梧村商业地下街，左右线分别侧穿BRT桥墩。针对复杂穿越条件下的地下街桩基托换、既有桥梁桩基保护等技术难题，提出如下措施： 1）采用纵向墙梁托换方案，将地下街的荷载传递至已完成的暗挖隧道结构和墙梁基础上； 2）对托换梁与旧桩的特殊节点进行处理，在桩身植筋、设置企口； 3）隧道采用锚杆支护，针对侧壁软弱土层进行注浆加固； 4）处理既有抗浮锚杆，在隧道进出洞范围内设置管棚。以上措施有效降低了施工对地下街的影响，确保了隧道施工和既有结构的安全。最后，数值模拟结果表明所采用的纵向墙梁托换方案是合理、可行且安全的，现场监测数据也与之吻合。

The mined tunnel of Xiamen railway station of rail transit line 3 is 34.5 m in width and 11.7 m in depth. The tunnel crosses underneath Wucun commercial underground street, and the double lines laterally cross the BRT piers. Accordingly, the existing pile foundations of the stress and piers should be underpinned. As a result, countermeasures are put forward as follows: (1) The longitudinal wallbeam underpinning scheme is adopted to transfer the load of the underground street to the completed station structure and wall beams. (2) The reinforcements are embedded in special joints between the underpinning beams and the existing piles, and the tongues and grooves are cut. (3) The tunnel is supported by anchor bolts, and the weak soil layer on the sidewalls is grouted and reinforced. (4) The existing antifloating anchor bolts are removed and pipe roof is arranged within the tunnel entrance and exit. The measures adopted have effectively reduced the impact of tunnel construction on underground street and the safety of the tunnel, and the existing structures have been ensured. Finally, the numerical simulation results show that the longitudinal wallbeam system is reasonable, feasible, and safe.