CUTTER DISK OF DIFFERENT-DIAMETER TUNNEL EXCAVATION SHIELD MACHINE, UNDERGROUND CONNECTION DEVICE AND UNDERGROUND CONNECTION METHOD THEREFOR

PURPOSE:To stop water in a tunnel joining area without requiring an auxiliary construction method and reduce the cost by shortening the construction period. CONSTITUTION:A shield machine main body 8, which is relatively movable in the longitudinal direction of a skin plate P, is installed to a small-diameter shield machine S1, while a tube seal 9 is installed into the tip of the skin plate P. A cylindrical body 4, which seals between the rear face of a cutter disk D1 and a shield machine main body 3, and a water stop ring 5 having a tube seal 7 in the inner peripheral area of the tip are installed to a large-diameter shield machine B1, thereby sealing the area. A projected disk 1, which has a diameter smaller than the inside diameter of the skin plate P of the small- diameter shield machine S1 is installed to the front surface of the cutter disk D1, and the skin plate P of the small-diameter shield machine S1 is arranged at the projected disk 1, and the gap is sealed with the tube seal 9.