PROTECTIVE STRUCTURE FOR A TUNNEL ENTRANCE TO SERVE AS AN OUTER FORM FOR AN OPEN-CUT TUNNEL

摘要

PURPOSE: A protective structure for a tunnel entrance is provided to protect workers and construction equipments from falling rocks or landslides and to serve as a form for an open-cut tunnel.;CONSTITUTION: A protective structure for a tunnel entrance is as follows. Steel supports(20) are installed in an open-cut tunnel(10) of a tunnel entrance at same interval. A primary shotcrete(22) is placed on the top of the steel supports. A secondary shotcrete(24) is placed on the top of the primary shotcrete. A waterproofing material(30) is spread from a shotcrete lining(14) of a pit(12) to the primary shotcrete of the open-cut tunnel. The open-cut tunnel concrete lining is constructed by utilizing the primary shotcrete of the open-cut tunnel as a form.;COPYRIGHT KIPO 2013;[Reference numerals] (AA) NATM starting point