SHIELD BORING MACHINE FOR EXCAVATING INTAKE TUNNEL

PROBLEM TO BE SOLVED: To provide a shield boring machine for excavating an intake tunnel which causes no clogging at a water permeable portion of an intake segment and prohibits the ingress of groundwater through a tail clearance. SOLUTION: In a shield boring machine for intake tunnel excavation which has a water permeable portion 7b and non-permeable portion 7c and assembles an intake segment for taking in water through the water permeable portion 7b in a tail plate of a rear drum 1b, surface contact type urethane seal 9 capable of forming the seal surfaces in the peripheral direction by surface-contacting to an existing intake segment is provided with a plurality of stages in the tail plate, in the process of movement of the tail plate relative to the intake segment, the attaching pitch and the number of stages of the plurality of stages of urethane seal 9 are selected in such a manner that at least one stage of the urethane seal 9 constantly contact either one of the non-water permeable portion 7c of the intake segment among a plurality of the stages of urethane seal 9.