CONSTRUCTION METHOD OF A TUNNEL USING A FRONT JACKING METHOD CAPABLE OF IMPROVING THE MOVABILITY OF A TUNNEL MEMBER UNDER THE GROUND

摘要

PURPOSE: A construction method of a tunnel using a front jacking method is provided to secure the safety on construction and traffic against live load on the ground, to improve the quality of construction and to execute a construction work economically. CONSTITUTION: The construction method of a tunnel using a front jacking method comprises the steps of: forming a departure base(3) on one side of the lower ground of a track(20) and a reach base(4) on the opposite side to the departure base(3); constructing a guide drift which connects the departure base(3) and the reach base(4); arranging strands on the guide drift; arranging tunnel members on the departure base(3), attaching a front shoe to the front of the tunnel member and installing a support and a traction jack to the reach base(4); anchoring both ends of the strand through an anchorage of the tunnel member and an anchorage of the traction jack; moving the tunnel member to the traction and target spots by tensioning the strand using the traction jack; after removing the front shoe, an anchor bolt, the traction jack and the anchorage from the reach base(4), anchoring the end of the strand using a third anchorage and remaining behind to make the strand function as a tension member against a tunnel member; and removing a traction jack, a support wall and temporary retaining walls(30,31) and restoring a departure base and a reach base.