Abstract: A brush-type packing means for shield tunnel excavators which is high in wear resistance and sealing effect against under ground water is provided. The packing means comprises a resilient wire brush secured substantially in a ring shape along the inner periphery of a substantially cylindrical excavator body adjacent its tail end or the peripheral edge of the tunnel entrance on the wall surface of the vertical shaft to close a gap space between the tail end or the entrance edge and the peripheral surface of a tunnel wall element inserted in an excavated tunnel, and clearances between respective brush wires are sealed with an impregnating agent which is deformable and impermeable to water.

Abstract: A brush-type packing means for shield tunnel excavators which is high in wear resistance and shielding effect against underground water is provided. The packing means comprises at least two rows of resilient wire brushes secured substantially in parallel ring shape along inner periphery of substantially cylindrical excavator body adjacent its tail end or peripheral edge of tunnel entrance on wall surface of vertical shaft as spaced in tunnelling direction to close a gap space between the tail end or the entrance edge and peripheral surface of tunnel wall element inserted in excavated tunnel, and the space between the respective rows of the wire brushes is sealed with a material which is viscous and impermeable to water.

Abstract: An apparatus and method for excavating tunnels with a shield and slurry while detecting and preventing excess excavation in high water content soft ground wherein, in each of feeding system of slurry to tunnel face and discharging system of a mixture of slurry and excavated soil or the like as well as gushing water from the tunnel face out of working area, the respective volumes of the slurry and mixture passing through the respective systems are measured in positions close to the tunnel face, the volume of the excavated soil or the like is determined with the difference between both volumes while the amount of propelling a tunnelling machine is determined as an excavated space volume of the tunnel, the respective values of the excavated soil volume and excavated space volume are compared with each other, whereby the amount of propelling the machine, fed amount of the slurry or discharging amount of the mixture can be properly adjusted so that the difference between said values will be made substantially zero

Abstract: An apparatus and method for measuring fluctuations in amount of soil in slurry or soil-containing fluid line. Each system of feeding the slurry typically to tunneling face and draining it therefrom in the slurry line is provided with gamma-ray densimeter and electromagnetic flow-meter to obtain respective amounts of soil only (dry-soil amounts) in the slurry flowing through each of said systems from respective outputs of these meters in each system, so that actually excavated amount through ground layer of a shielded excavator at the tunneling face can be measured by the difference between the respective dry-soil amounts. The excavator will be advanced depending on this measured amount.