花东铁路电气化新建工程之溪口隧道(3 140 m)及光复隧道(2 360 m)是平原区浅覆盖隧道，内空净宽11.3 m，布设2股轨道及两侧维修步道。隧道施工以明挖覆盖工法为主，但在过河段穿越寿丰溪北岸(75 m)及南岸(85 m)堤防段、马太鞍溪北岸(170 m)及南岸(120 m)四处堤防段则采用隧道钻掘工法施作。钻掘隧道覆土高6～18 m，穿越砾石层，开挖断面宽度13.7 m，断面积131.3 m2。钻掘隧道开挖采新奥工法(NATM)进行，因覆土浅且地质松软，拱作用难以形成，开挖时需配合地盘改良及先撑管幂进行。施作方式依序为地表垂直钻孔进行固结灌浆、打设先撑管幂，隧道开挖时则以钢支保、喷混凝土及岩栓作为临时支撑，最后施筑钢筋混凝土内衬砌。

The XiKou tunnel (3 140 m) and KuangFu tunnel (2 360 m) are the shallowcovered tunnels of the HauTung railway electrification project, inner width is 11.3 meters, two railway lines and two maintenance walkways at each side are arranged. The cutandcover method of tunnel construction was mainly adopted, but the underground drilling method was used at 4 sections of passing through the north and south dikes of ShouFeng stream (75 m & 85 m) and the north and south dikes of MaTaiAn stream (170 m & 120 m) between the crossriver tunnels. The overburden of drilling tunnels is about 6~18 m in thickness, passing though the gravel layer, and the excavated profile is 13.7 m wide and 131.3 m2 in area. The New Austrian Tunneling Method (NATM) was used for these sections mentioned above. Due to the shallowcovered soil, the arch action can’t form, therefore, the ground improvement and pipe roofing method should be executed before excavating. The construction procedure was grouting from groundsurface, installing pipe roofing, excavating and temporary supporting by steel ribs, shotcrete, and rock anchors, at last constructing concrete inner lining. These cases were successfully completed.