Abstract: An excavation controlling method for hydraulic shield tunnelling wherein decisions are made during advances of tunnel excavation on whether respective excavated soil amounts per macroscopic unit distance belong to the same statistic population and, with respect to excavated amounts per microscopic unit distance divided out of the macroscopic unit distance, whether excavated amounts per microscopic unit distance of the same dividing order belong to the same statistic population.

Abstract: A shield type hydraulic tunnel boring machine having means for detecting an occurrence of excess excavation due to accidental collapse in tunnel face ground apt to occur during tunnel boring works through soft and unstable ground and for further determining the location, shape, scale and the like of such excess excavation occurred is provided. The means comprises optimumly a plurality of ultrasonic wave transmitting and receiving devices disposed as spaced at least along a radial line on the front surface of a substantially disk shaped rotary cutter head of the machine for transmitting ultrasonic waves in forward and upward directions and receiving reflected waves from tunnel face ground wall, a wave transmission and reception controlling means, and a transmission-to-reception time interval detecting means for determining distances from the respective wave transmitting and receiving devices to the ground wall.

Abstract: A device for removing relatively larger size gravels, stones, crushed rocks and the like contained in a discharged mixture of fed slurry or muddy water and excavated ground formation components in hydraulic tunnel boring systems. The device comprises a lattice-shaped classifying means connected at one end to a discharging pipe for conducting the mixture from the tunnel face, a primary chamber connected to the other end of the classifying means for receiving and storing classified gravels and the like, and a secondary chamber communicating with the primary chamber through a valve for receiving and retaining the gravels and the like filled in the primary chamber. A housing surrounds and rotatably supports the classifying means and includes a discharging pipe for conducting muddy water passed through the clarifying means. A motor rotates the classifying means for performing classifying work.

Abstract: A tunnel driving and forming method with hydraulic boring machine through mixed ground of stable and unstable layers which is simplified in equipments, less in air contamination and noises and high in working accuracy. The method comprises steps of driving the hydraulic boring machine into the ground to bore a tunnel therein, installing segments sequentially against bored tunnel wall right behind the machine as the same advances, impregnating a back-filling agent between said bored tunnel wall and outer periphery of installed segments, removing the rearmost set of a certain number of sets of said installed segments behind the machine for circulatory use as long as the ground bored is stable, reinforcing exposed surface of said back-filling agent impregnated and set, and repeating respective said steps responsive to advances of the machine.

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 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.