Patent KR-100826666-B1 (KR)
Title: 2 arch-tunnel with precast concrete support wall and construction method of the same
Inventor: PARK JAE HYUN
IPC: E21D11/00
Filed: 2007-01-12
Granted: 2008-05-22
Abstract: A two arch tunnel having a bearing wall manufactured separately and a construction method of a two arch tunnel are provided to shorten a period of construction by omitting multistage placing processes, to perform construction work exactly by heightening the strength and dimensional accuracy of a bearing wall, to have a bearing wall having strong durability against an impact caused by blasting in excavation work of a two arch tunnel, and to perform deferred maintenance work by improving a structure. A two arch tunnel having a bearing wall manufactured separately includes a pilot tunnel(10), a bearing wall(100), and a pair of running tunnels(20,30). The pilot tunnel includes a base(200), a bearing wall, a coupling member, and an upper support(75), wherein the base is composed of a drainage way(210), a housing(220) and a drainage way guide pipe(211) and formed on the bottom of the pilot tunnel to support the bearing wall and the upper support, the housing is formed to house the bearing wall in the base partially to function as a foundation for preventing the separation of the bearing wall from the base while blasting in excavation work for the running tunnels and to guide plural bearing walls arranged in the longitudinal direction of the pilot tunnel, the drainage way is formed to discharge the effluent water flowing inward from the upper part of the bearing wall to the outside, and the bearing wall includes a reinforcement part(110) formed on the lower part of the bearing wall to support the entire bearing wall, a column part(120) formed on the upper part of the reinforcement part to support a lining connection part, a lining connection part(130) formed on the upper part of the column part and bent outward in an arc shape like lining concrete(23,33) to be supported correspondingly to the lining concrete included in right and left running tunnels of the pilot tunnel, one or more drainpipes(140) provided in the bearing wall to drain off effluent water gathered in the upper part to the lower part of the pilot tunnel, a tension connection member(150) penetrating in the longitudinal direction of the pilot tunnel to keep the fixed tensile force after plural bearing walls are connected, and a shear resistance member(160) buried under the upper part of the bearing wall partially and coupled to the upper support partially to correspond shear stress occurring while blasting in excavation work of the running tunnels. In addition, a waterproof plate(400) is installed between the bearing wall and the upper support to prevent the inflow of effluent water flowing inward from the upper part of the pilot tunnel to the bearing wall. A construction method of a two arch tunnel comprises the steps of: excavating a pilot tunnel; placing a base on the bottom of the pilot tunnel; conveying a bearing wall manufactured separately to the upper part of the base using a conveyor member; inserting the bearing wall conveyed to the upper part of the base into a housing of the base, and coupling the base and the bearing wall using a coupling member; installing a waterproof plate on the upper part of the bearing wall in the longitudinal direction of the pilot tunnel; coupling a shear resistance member to the upper part of the bearing wall, and placing an upper support; excavating running tunnels in right and left sides of the pilot tunnel; placing paving concrete on the ground of the running tunnels; and placing lining concrete from the upper support to the entire arch surface of the running tunnels.