臺北捷運內湖線CB420標自松山機場站（BR1）東端起，以潛盾隧道通過松山機場下方 至濱江街通風豎井，全長1200餘公尺，共設置2處連絡通道，長度均為20公尺。在設計階段 考量施工因素及降低對機場跑滑道之影響，特將連絡通道的位置安排於機場草皮區下方，惟 工程開工後，因航站重新規劃，將其中一處連絡通道（CP1）上方草皮改建為停機坪，此改 變對於本連絡通道之地盤改良、開挖支撐、結構施工等均造成不利之影響。本文描述本連絡 通道在地表條件改變下，各工項之施工過程及因應地表改變之各項措施。

The shield tunnel of Neihu line's Contract CB420 goes underground on the southern side of the Songshan Airport (BR1 Station), then tunnels northbound beneath the airport and the Keelung River, reaching Beian Road in Dazhi (B1 Station). The route is approximately 1.2 km, and 2 cross passages have been set up. There were two 20-meter cross passages beneath the grass verge of the Songshan Airport in the detailed design. During the detailed design stage, due to construction factors and to reduce the impact on the runway, the cross passages were placed beneath the airport's grass verge. Unfortunately, the grass verge above CP1 was replaced with the rigid pavement of runway apron and this caused a series of changes in the construction approach, such as ground treatment, excavation, and strut systems. This article details the revised measures that were implemented due to the changes in ground conditions.