求翻译：洞口段采用明挖法施工，明洞采用“套拱法”施工，在隧道明洞衬砌轮廓线外，立模浇注长2m厚60cm的混凝土套拱，以确保洞口段岩体的稳定，套拱内预埋导向钢管，作为超前管棚时做导向用。是什么意思？

Hole section with open-cut method of construction, Myeong-dong a "set of arch method" construction, Myeong-dong in the tunnel lining contour, the legislation die casting long 2m 60cm thick concrete arch units, to ensure the stability of rock hole, set arch embedded within the guide tube, pipe roof a

Introduction Paragraph hole cut-and-law, Myeong-dong construction using "set" the law in the tunnel construction, Myeong-dong skyline, lining the mold pour a 2m 60cm thick, with a view to ensuring that the concrete arches set paragraph cave rock arches set within a stable, pre-buried-oriented steel

The Dongkou section uses the open excavation law construction, the bright hole use “the set of arch law” the construction, outside the tunnel bright hole lining work contour line, sets up the mold to pour long 2m thick 60cm a concrete set of arch, guarantees the Dongkou section rock mass the stabili

Portal uses open construction, Myeongdong "arch" method construction and lining in tunnel contour lines, vertical die casting long 2m 60cm of concrete arches, rock mass stability to ensure entrance, within Arch embedded-oriented steel pipe, as do advance pipe roofing Guide.

Hole section with open-cut method of construction, Myeong-dong a "set of arch method" construction, Myeong-dong in the tunnel lining contour, the legislation die casting long 2m 60cm thick concrete arch units, to ensure the stability of rock hole, set arch embedded within the guide tube, pipe roof a