Abstract: A form structure for making a primary concrete covering wall on the surface of the wall of a tunnel which extends behind a shield type tunnel excavator advanced, wherein a form structure for casting concrete to make the covering wall is assembled with a plurality of arcuate form assemblies respectively including form segments and timbering members for reinforcing the cast and set concrete. The form segments of each assembly are detachably coupled to the timbering members. The form structure is disassembled after the cast concrete is set by detaching the form segments of the respective assemblies from the timbering members to leave the members on the primary covering wall of the set concrete, whereby the primary covering wall can be held in stable state simultaneously with completion of the primary covering wall on the tunnel wall surface.

Abstract: A method for lining a tunnel wall formed by a shield excavation includes filling a space between the tunnel wall surface and the outer peripheral surface of a lining form in two stages by dividing space into two, portions. One stage of the method is carried out with a ring-shaped rearward end frame ring secured to excavator propelling jacks and disposed to define a first space portion and a second stage of the method is carried out accompanying forward propulsion of the excavator.

Abstract: A method of making a primary concrete covering wall on the surface of the wall of a tunnel which extends behind a shield type tunnel excavator. A form structure for casting concrete to make the covering wall is assembled with a plurality of arcuate form assemblies respectively including form segments and timbering members for reinforcing the cast and set concrete. The form segments of each assembly are detachably coupled to the timbering member. The form structure is disassembled after the cast concrete is set by detaching the form segments of the respective assemblies from the timbering members to leave the members on the primary covering wall of the set concrete, whereby the primary covering wall can be held in stable state simultaneously with completion of the primary covering wall on the tunnel wall surface.

Abstract: A tunnel wall lining method is provided, wherein annular recesses circumferentially are provided in outer periphery of a lining form into which arcuate segments are assembled, a plurality of rows of reinforcing bars are arranged annularly in the respective recesses of the lining form, and a lining is constructed with concrete cast into a space between the tunnel wall and the lining form. The lining thus constructed includes circumferentially extending and radially inwardly projecting beams in which the reinforcing bars are embedded, whereby a lining having a reinforcing structure can be constructed in a simple and economical manner and in a shortened construction period.

Abstract: An automatic fire extinguisher wherein a fire detector receives infrared rays from started fire flame in detecting area at one of many light receiving elements which corresponds to the ray's incident angle into an assembly of infrared-ray passing filter and condenser lens, variations in detected output of the detector resulting from flaring of the fire flames are discriminated, the detected output higher than a predetermined level controllably drives an ejection nozzle to direct it towards the point of the flames and discharges a fire extinguishant out of the nozzle towards the flames, achieving thus a reliable detection and effective extinguishment of only such started fire while preventing any erroneous operation due to other infrared ray sources.

Abstract: An automatic fire extinguisher wherein a fire detector receives infrared rays from started fire flames in detecting area, as unified in the incident amount of the rays, at one of many light receiving elements which corresponds to the ray's incident angle into an assembly of infrared-ray passing filter and condenser lens, variations in detected output of the detector resulting from flaring of the fire flames are discriminated, the detected output higher than a predetermined level controllably drives an ejection nozzle to direct it towards the position of the flames and discharges a fire extinguishant out of the nozzle towards the flames, achieving thus a reliable detection of the fire irrespective of its distance from the detector as well as an effective extinguishment of only such started fire while preventing any erroneous operation due to other infrared ray sources.

Abstract: A method of building a strengthened embankment body which involves the steps of repeatedly burying first nets and embanking and roll-compacting the body being built on ground until a required height of embankment is reached, repeatedly burying of second nets between the buried first nets and embanking and roll-compaction of compression-resistive materials are concurrently repeated to form a highly strengthened arched body part locally at a zone corresponding to an arched peripheral wall of a semi-cylindrical tunnel to be excavated through the body, the first buried nets providing the stability of the entire embankment body while the second buried nets achieving the stability at the arched peripheral wall zone of the tunnel.

Abstract: A method of building a strengthened, embanked foundation capable of forming therein a tunnel comprising steps of burying, during embanking work of lower part of the foundation, a plurality of nets as vertically spaced in embanking material for the foundation at least in its internal zone including side wall portions of the tunnel later formed so as to substantially horizontally intersect imaginary sliding surfaces occurring in the portions upon excavation of the tunnel, forming a crushed-stone arch layer overlying from both upper side portions to upper central portion of the later formed tunnel during further course of the embanking, work providing a hanging support to ceiling wall portion of the later formed tunnel as coupled through hanging rods to the arch layer during its formation, and, after completion of the embanking, excavating a zone defined by the side and ceiling wall portions in the embanked foundation to form the tunnel therein.

Abstract: A method of building a hollow structure in an embankment during its embanking work, wherein portions inside the embankment which are to form slope or side wall layers of later excavated cavity for the structure are embanked simultaneously with remaining portion of the embankment, with a plurality of nets buried as vertically spaced and to substantially horizontally intersect sliding surfaces appearing in said layers upon excavation of the cavity, upper ceiling portion of the cavity later excavated is prestressed during further embanking work by means of at least crushed stone filling between supporting plates buried respectively above each of said slope layer portions as opposed to each other with their surface and coupled by steel wires tightly hung between them, and after completion of the embanking work the cavity is excavated by removing embanked material in a zone surrounded by the slope layer portions and prestressed ceiling portion, so that the structure can be built within the cavity with the slope la

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 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 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 rod-shaped members capable of being extended out of and retracted into the machine. Amounts by which these members are paid out until they reach ground wall of any cavity due to the occurred excess excavation are measured to determine the actual state of such cavity. The means is provided preferably at a plurality of proper positions on a shield body of the machine and respective values of the measured amounts at these positions are recorded and displayed, whereby the location, shape, scale and the like of the occurred excess excavation can be confirmed.

Abstract: An improved attitude control system for tunnel boring machine shields is provided. A laser beam transmitter is installed in an already bored tunnel behind the machine shield for transmitting a laser beam in parallel to a predetermined tunneling direction and a device for receiving the beam is installed in the shield for detecting any deviation of the shield from the beam so that, when the deviation is detected during tunneling work performed by rotating a foreward end cutter head of the shield and propelling the shield toward tunnel face ground with a plurality of jacks installed at rearward end of the shield, the jacks are selectively driven in response to resultant deviational direction and amount of the detection so as to remove the deviation.

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: Attitude controlling method of tunneling machine shield and system for performing the method, wherein a plurality of jacks installed at a tail end of the shield for propelling the same toward tunnel face ground are selectively driven when the shield deviates from intended tunneling direction. Such deviation detected is first indicated in an indicating and controlling unit and then the unit is operated to actuate an associated circuit connected to the respective jacks in accordance with the indicated deviation so that selective ones only of the jacks effective to correct the deviation will be driven.

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: An apparatus for automatically controlling tunnel face hydraulic pressure in a hydraulic chamber defined by a rotary cutter head and bulkhead in a shield type excavator used in hydraulic tunnel boring system including a pipe for feeding a hydraulic material with a feeding pump from a reservoir to the chamber and a pipe for discharging a mixture of the fed hydraulic material with ground formations excavated by the cutter head from the chamber to the reservoir with a discharging pump.

Abstract: An apparatus for automatically controlling tunnel face hydraulic pressure in a hydraulic chamber defined by a rotary cutter head and bulkhead in a shield type excavator used in hydraulic tunnel boring system including a pipe for feeding a hydraulic material with a feeding pump from a reservoir to the chamber and a pipe for discharging a mixture of the fed hydraulic material with ground formations excavated by the cutter head from the chamber to the reservoir with a discharging pump.

Abstract: A method of completing a tunnel excavation with a slurry shield type tunneling machine through a soft ground having a high water content or much gushing water, advancing the machine from the ground into a vertical shaft at, for example, a tunnel terminating point while preventing any ground collapse or gushing water at a vertical shaft wall finally excavated, and an apparatus for performing the method.

Abstract: A method of and apparatus for starting a tunneling operation into a soft ground having a high water content or much gushing water while preventing any collapse of the ground or outflow of water. The tunneling machine is initially placed within a vertical shaft in the ground and a sheet pile is struck into the ground between a retaining wall of the shaft having a starting port through which the machine is to be ultimately advanced into the surrounding ground after the port is opened by raising the pile. A ring-shaped liquid-tight packing is applied to the retaining wall and surrounding the starting port engages the periphery of the head portion of the tunneling machine to form part of a liquid-pressurized chamber in front of the machine, the pressure in the chamber being at least as high as the surrounding underground water or ground pressure when the port is opened and the machine is then started through the port.