CONSTRUCTION DEVICE FOR BASE OF UNDERWATER TUNNEL

PROBLEM TO BE SOLVED: To adjust the height of the slide support of an underwater tunnel by providing launching girders, work rooms and a pressure adjusting device, and constructing the support beds of an underwater tunnel with the work rooms. SOLUTION: Launching girders 410 are fitted to a caisson 400, work rooms 701 are provided on them to make height adjustments 706 of support beds 232. The launching girders 410 are extended in the water through a bulkhead 704. The launching girders 410 are made of steel pipes, and some parts of work inspection shafts 702 are used as work passages. Ballast water is injected into the steel pipes to reduce the buoyancy of the launching girders 410. Water can be injected into and discharged from holding shafts 703. The work rooms 701 are fitted to the work inspection shafts 702. Pressure adjusting rooms 705 are arranged in the caisson 400 to adjust the air pressures of the work rooms 701 via the work inspection shafts 702. The support beds 232 are arranged in the work rooms 701, the water levels of the work rooms 701 are lowered when the air pressures are increased, and the heights of the support beds 232 are adjusted. The support beds 232 of an underwater tunnel can be accurately adjusted.