都会区新建公路隧道，一般受限于住宅稠密与用地取得面积，往往须缩减隧道间之距离，因而衍生出隧道连拱行为。本文以台湾新北市新店地区新建三连拱小净距隧道为例，探讨设计开挖支撑方法。本案例隧道所经过地质材料强度低，连拱开挖后剩余中间岩柱强度不足以支撑上方岩体，因此采用三连拱眼镜式中间导坑开挖工法，并构筑混凝土壁体，作为主隧道间岩体强度改良以及隧道临时开挖支撑承载点，其设计经验希供后续类似案例之参考。

Building a new highway tunnel in the metropolitan area is generally limited by the dense residential area, where the land acquirement is difficult, therefore the distance between the tunnel tubes has to be reduced, which derives the triplearch closelyspaced tunnel. In this article, the design of the excavation and support method of triplearch closelyspaced tunnel is investigated, with the newlybuilt triplearch closelyspaced tunnel in Xindian District, New Taipei, Taiwan as an example. The geological material of the tunnel in this case is weak, which leads to the lacking of the strength of the middle pillar after the excavation of the triplearch tunnel, therefore triplearch glassstyle central pilot tunnel excavation method is adopted for the tunnel and concrete walls are built for the tunnel to improve the strength between the main tunnels and to provide support bearing point in the temporary tunnel excavation. It is hoped that the design experience described can provide reference for subsequent similar cases.