Abstract: A small diameter shield tunnel is constructed by using a shield machine and assembling within a tail portion of the machine a set of three 120.degree. arcuate segments into a segment ring. An annular seal device is axially movably provided between the outer periphery of the segment ring and the inner periphery of a tail skin plate defining the tail portion of the machine. A back-filling material is charged into an annular gap formed between the outer peripheral surface of the segment ring and natural soil surrounding the segment ring. The back-filling material within the annular gap is compressed by the seal device which is caused to move between the inner peripheral surface of the tail skin plate and the outer peripheral surface of the segment ring, in the axial direction of the tunnel, away from a face where excavation of natural soil is carried out mechanically.

Abstract: A gelling agent is added to a fast setting cement slurry comprising water, cement and anti-washout retarder and the mix is injected into a void containing running water and allowed to set to form rapidly a material of high compressive strength.

Abstract: An insulating and rehabilitation system especially adapted to unlined rock tunnels forthe prevention of ice buildup on tunnel arches, walls and base structurethe prevention of future deterioration of tunnel rock structure resulting from freeze-thaw cycle, andthe stabilization of present tunnel rock structure which has been weakened by prior freeze-thaw cycles.The system comprises a modular system of sandwich panels with protected metal skins and insulating cores, prefabricated as a complete liner system to conform with tunnel dimensions and clearance requirements.

Abstract: A method and apparatus for laying pipes of low bearing force like a polyvinyl chloride pipe and others in the ground with a propulsion pipe laying method, wherein an excavation device to excavate a tunnel to lay pipes therein is propelled into the ground by a propulsion force exerted on a propulsion shaft joined behind an excavation device while the pipes to be laid are run over the propulsion shaft and propulsion shaft bodies are joined one after another to propulsion shaft bodies and the pipes are joined one after another to pipes. The propulsion shaft bodies have a supporting device on the outer periphery thereof which rigidly supports the inside surface of pipes run over the propulsion shaft. With this supporting power, pipes to be laid are propelled into the tunnel in accordance with an advancement of the propulsion shaft.

Abstract: A traveling culvert/tunnel forming structure including upright waler assemblies positioned in transversely spaced relation on each side of said forming structure, the waler assemblies being adapted to receive forms on outside surfaces thereof. Horizontally adjusted header assemblies are supported at opposite ends by the spaced upright waler assemblies. Collapsible braces are disposed between the upright waler assemblies enabling the upright waler assemblies to move towards and away from one another. Multi purpose mounting brackets are mounted in rows on the upright waler assemblies which brackets are positioned inwardly from the waler assemblies. Rows of casters are swivelly mounted on the brackets inside of the rows of upright waler assemblies beneath the header assemblies. A pair of rows of leveling jacks are provided for elevating the forming structure and its casters out-of-contact with a ground supporting surface. The leveling jacks each have an upstanding jack shaft.

Abstract: A tunnel lining process and an apparatus for use in the process in the prior art are improved in order to greatly enhance a lining speed and to facilitate the work of placing concreate for lining. The improvements reside in that a pressing form for pressing a tunnel concrete lining and a side form to be positioned on the side of the pressing form opposite to an already placed concrete lining are constructed as separate bodies in distinction from the prior art. After the pressing form and the side form have been disposed along an excavated surface of a tunnel, lining concrete is placed in a space delimited by the both forms, the excavated surface and the already placed concrete lining so as to press the lining concrete onto the excavated surface to be lined.

Abstract: Disclosed is a continuous tunneling and lining machine. The machine is capable of simultaneously boring and lining a tunnel through a solid medium. The machine comprises four major components including: (1) an excavation system; (2) a debris removal system; (3) a lining system; and (4) a liner material retrieval system. The excavation system comprises a rotary excavator that excavates the tunnel bore. The lining system mixes liner materials at the bulkhead and pumps the mixed material into slipform. The slipform comprises an inner form, an outer form and a wall connecting the inner and outer form and at least one mandrel. The mandrels form cast in place passageways to accommodate liner component retrieval and excavation debris removal. The debris removal system pumps excavation debris through the excavated area into the mandrels and out the cast in place passageways.

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: In my process for digging a tunnel with the help of a tunnel excavator which has a working chamber under atmospheric pressure, the local front wall is supported with the help of a pressurized medium which is connected by a controlling gap of a shield cover with another gap between a shield cover tail and/or the earth or ground and a tunnel-lining member. The gap is closed-off from the working chamber by a gap-sealing ring between a shield cover tail and a tunnel-lining member. Concrete is forced into the gap by a feeder pipe in the gap-sealing ring. A self-sealing permeable joint between the gap-sealing ring and the shield cover tail and/or the tunnel-lining member of the excavator is made with concrete which has a fine-grained additive material and a large-grained additive material so that the large-grained additive material forms a grain filter whose pores are closable by the fine-grained additive material.

Abstract: The movable tight-sealing ring is positioned between an excavator cover end and a form or casing structure. For a satisfactory movability of the excavator cover end interstice, the tight-sealing sealing ring is supported resiliently by adjustable supporting units freely movable relative to the excavator cover end and the casing or form structure. On one side the tight-sealing sealing ring is provided with a plurality of impressed material feed openings and on the other side with an elastic outer sealing member contactable on the inside of the excavator cover end as well as an elastic inner sealing member pressable against the outside of the form or casing structure.

Abstract: A method of lining an existing pipe by pulling through it a collapsible, flexible, lay-flat liner having an innermost layer of impervious, elastomeric material which is compatible with the fluid to be carried by the pipe, a textile reinforcing intermediate layer, and an external protective layer of elastomeric material. The liner has an external circumference slightly less than the internal circumference of the pipe and is such that flow of fluid through the liner after the installation thereof expands the liner into non-binding contact with the internal surface of the pipe. The peripheral extension (diametral swell) of the liner at the intended working pressure of the relined pipe should be less than 10% and preferably less than 5%.

Abstract: A method and apparatus for closing or sealing the gap space defined between a tunnel support frame and the ground during the tunneling formation of adits in connection with underground mining operations and the construction of underground tunnels, wherein backfill concrete is introduced into the gap space, comprises the disposition of inflatable bags within the gap space so as to be in abutment with the backfill concrete. In this manner, proper and complete backfilling is able to be achieved whereby the cured backfill concrete will exhibit proper structural integrity. The bags may be fabricated from a suitable plastic foil and are provided with an inflating-deflating valve. The bags can be reused upon subsequent support frame sections as the tunneling operation progresses.

Abstract: This invention is both an apparatus and a method for distributing concrete coming from a concrete pump to anyone of a plurality of points of use. An intermediate conduit is connected with a main supply conduit and the intermediate conduit comprises a plurality of branch points connected in series by the intermediate conduit. At each branch point a short branch pipe is connected with the intermediate conduit. All branch pipes can be completely plugged by rubber plugs. A discharge conduit is connected with the end of the intermediate conduit and a draining device can be operatively connected with the discharge conduit to force a deformable plug through the intermediate conduit and at least a part of the supply conduit in order to drain and cleanse the whole system before setting of the concrete will begin. The draining process is activated at the end of a working day or working period and can be automatically started after a predetermined stop period of the concrete pump.

Abstract: The present invention is directed to the control of the movement of slip liners in grouting operations through the use of inflatable grouting bags and to the control of bulkhead sealing in slip liner grouting operations.

Abstract: An apparatus for building a new pipeline while breaking a plurality of existing pipelines extending parallel to each other, comprises: a shield tunnelling machine for performing the excavating operation while breaking opposed portions of a plurality of existing pipelines; and a basic thrust mechanism for thrusting a new pipe into a space obtained through excavation by the machine while advancing the machine; wherein the shield tunnelling machine includes a shield body, a cutter assembly disposed in front of the shield body to be rotatable about the axis parallel to the axis of the body and dimensioned for breaking opposed portions of the existing pipelines while the body is advanced and a pair of stabilizers positioned on the outer periphery of the body so as to project respectively from a pair of opposite outer peripheral portions of the body and dimensioned to be slidably engaged with the remaining portion of the existing pipelines opposed to each other when the body is advanced.

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 form for a concrete tunnel lining usable behind a tunnel excavator with a traveling shield is made of an inner tunnel-lining sheathing and a form front. The inner tunnel-lining sheathing is divided into a plurality of sheathing segments or rings movable independently of each other with intervening segment-bridging yieldable joints. The form front located between the traveling shield and the inner tunnel-lining sheathing is movable forwardly by the conrete which presses in the annular space formed by the traveling shield and/or the surrounding earth and by the inner tunnel-lining sheathing as well as the form front. An operationally beneficial design results when the inner tunnel-lining sheathing is set up for forward motion of the sheathing segments in the tunnel longitudinal direction singly or in groups one after the other relative to the remaining sheathing segments held or remaining at rest.

Abstract: A process for lining a tunnel with concrete behind a tunnel excavator having a for front advanced along with an excavator head in which the concrete is forced between the surrounding subterranean geological structure and an inner tunnel-lining form through a form front which rides sealingly on the outer surface of the inner tunnel-lining form and on the inner surface of the shield. Simultaneously, the form front, which is longitudinally movable relative to the shield, moves forward relative to the inner tunnel-lining form. The form front is movable forward simultaneously balancing the friction forces occurring between the form front and the shield and the inner tunnel-lining form. Satisfactory results are obtained when the friction forces between concrete sections of a predetermined length are measured by moving the form front relative to the stationary shield and the inner tunnel-lining form during an interruption in concrete feed.

Abstract: Method and device for driving a tunnel by means of a tunneling machine (10). At the same time as the tunnel is driven, an injection hole (91) is drilled in front of the tunnel front (90) by a rock drilling machine (53) placed behind the tunneling machine.

Abstract: A refurbishing method for an existing pipeline under the sea or on the ground by inserting a rigid inner pipe having its front end temporarily blocked includes (a) driving the rigid pipe by increasing the volume of the fluid filled and sealed in the new pipe, (b) driving the new pipe by an axial force with the aid of a holder at the rear rim of the new pipe, and (c) regulating the movement of the new pipe. An apparatus to carry out the above-mentioned method is also provided. After inserting one pipe, all defines of the apparatus are detached, then another new pipe is connected, and repeated insertions end up as complete pipeline.

Abstract: An apparatus for moulding prefabricated curved concrete sections for use in the construction of arched or vaulted structures comprises a curved, upwardly convex mould made up of a series of reusable substantially flat mould plates pivotally supported by vertical pillars of adjustable height. The mould plates are hingedly connected to each other such that the angle of each plate to the adjacent plate is adjustable. The spacing between the vertical pillars is also adjustable, so that the mould plates provide a polygonal mould surface adjustable for moulding prefabricated concrete sections of different curvatures.

Abstract: A tunnel having an inner surface and extending along an axis is lined with pumpable concrete having a predetermined hardening time and by a form having an annular inner wall and an axially movable front wall. Substantially equal sized batches of pumpable concrete are successively injected into the space through the movable front wall through a plurality of angularly equispaced ports therein. The batches are injected axially backwardly through the ports at such a rate that succeeding batches are injected through each port at a time interval that is substantially smaller than the concrete hardening time. The front wall is displaced forward at such a rate and the batches are sized such that each batch spreads over a predetermined axial and a predetermined angular distance, such that the latter is greater than the former.

Abstract: The known method for constructing a tunnel of the type in which a shield tunnelling machine is shoved by means of a concrete lining jack and a shield jack equipped on the shield tunnelling machine with reaction forces received by concrete for lining placed in a space delimited by an inner form assembled within a tunnel bore successively dug by the shield tunnelling machine, a shield tail and an already placed concrete lining, as well as by the inner form, is improved in order to construct a main tunnel body as a reinforced concrete structure. The improvements include in that a reinforcing steel cage is mounted to a combined spreader and end form of the concrete lining jack via metal mounts, the placed concrete for lining is compressed while the reinforcing steel cage is moved, and thereby the reinforcing steel cage is disposed at a predetermined position within the concrete for lining by adjusting the stroke of the concrete lining jack.

Abstract: Shield tunnelling method and assembling and disassembling apparatus for use in practicing the method. A shield having shield jacks is actuated for drilling a hole in the ground. Inner forms and outer forms are assembled into a plurality of tubular units coaxially jointed in the hole so that an annular concrete lining space is defined between the inner forms and the outer forms, the tubular units having a leading tubular unit.The shield jacks are applied against inner forms of the leading tubular units for thrusting the shield during actuating of the shield to further drill the hole. A concrete is injected into the annular concrete lining space to form a concrete lining. The concrete lining within a predetermined length of tubular units is set for providing adhesion to the inner forms, in contact with the concrete lining, against a reaction force of the jack thrust for the shield.

Abstract: A tunnel excavator has a substantially tubular shield having rotatably mounted on one end a motor-driven cutting disk rotatably carrying a multiplicity of roller cutters. The shield is comprised of a head section having front anchors in addition to the cutting disk, an inner section telescopically nested in the head section and constrained to only axial displacement relative to the same, and a tail section having rear anchors and coupled to the inner section for both bending and rolling movements relative to the same. Hydraulic push jacks act between the head and tail shield sections for advancing the shield. A pair of hydraulically independent antirolling jacks are connected between the inner and tail shield sections so as to enable the tail shield section, which is anchored during excavation, to bear against the rolling of the head shield section.

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: Disclosed is a continuous tunneling and lining machine. The machine is capable of simultaneously boring and lining a tunnel through a solid medium. The machine comprises four major components including: (1) an excavation system; (2) a debris removal system; (3) a lining system; and (4) a liner material retrieval system. The excavation system comprises a rotary excavator that excavates the tunnel bore. The lining system mixes liner materials at the bulkhead and pumps the mixed material into slipform. The slipform comprises an inner form, an outer form and a wall connecting the inner and outer form and at least one mandrel. The mandrels form cast in place passageways to accommodate liner component retrieval and excavation debris removal. The debris removal system pumps excavation debris through the excavated area into the mandrels and out the cast in place passageways.

Abstract: An apparatus for making a tunnel lining from concrete in a single operation with a tunnel excavator comprises a tunnel lining form consisting of a plurality of tunnel lining form segments and a form front adjacent the tunnel excavator and a tunnel lining circular space between the form and the ground. The concrete is selected so that it remains workable for more than two hours at a temperature of about 20.degree. C. but sets to a nonworkable state after 10 to 30 minutes upon heating to a temperature in the range of substantially 40.degree. C. to substantially 70.degree. C. The concrete is heated in a pipe section proximal to the compartment into which it is introduced by direct introduction of electrical energy into the pipe section.

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: A device for laying and suspending cables (38), in particular low-voltage, medium-voltage and signal cables, is fitted in a man-sized duct or tunnel with brackets (10) secured in spaced relationship on the inner periphery of the duct or tunnel or on diagonal braces. These brackets are used for supporting cables (38) drawn in guide tubes (32).The brackets (10) projecting into the duct or tunnel are made tubular and have at least one flat outer surface (42, 44) extending over the entire length. The brackets are equipped with a locking device (22) at the free end (20).A guide connection (24) of at least one tube saddle (26) having a hard-plastic cable guide tube (32) which runs approximately at right angles to the longitudinal axis (A) of the guide connection (24) and of the bracket (10) and has a low coefficient of friction is arranged on each bracket (10).

Abstract: Soil drilling tools are provided with at least two sidewardly movable plate members adapted to exert pressure on the wall of a bore hole to prevent a cave in.

Abstract: A method and apparatus for forming wet concrete employing a slip form having a radially expandable elastic outer shell comprising pouring concrete around the exterior surface of the outer shell and applying a fluid under pressure to the interior surface of the outer shell. The pressure of the fluid is pulsated so that the outer shell expands and contracts to reduce the friction between the outer shell and the concrete. The reduction in friction allows the form to be moved longitudinally along the concrete with reduced tearing of the surface of the concrete.

Abstract: For continuously lining a tunnel with extruded concrete a pumping device for feeding the concrete and a form having an interior form member and a forwardly movable form front are employed. The extruded concrete is put into place without clump formation, when it is provided in equal-sized segments in a plurality of equal constant amounts which are fed in succession one after the other circumferentially in a time interval which is small compared to the hardening time of the concrete. For this purpose the form front is provided with a plurality of concrete input ports uniformly distributed circumferentially and connected with the pumping device, while the pumping device is designed to service the concrete input ports in succession one after the other circumferentially.

Abstract: An improved concrete lining machine is provided for lining the walls of a bored tunnel. The machine typically consists of three separable machine sections each having a frame and a plurality of supporting plates rotatable in an endless loop chain. Fresh concrete is sealed from the second machine section by a plurality of adjoining main and auxiliary plates which remain in place relative to the concrete until the concrete is at least substantially cured. According to the method of the present invention, the first machine portion partially supports the bored tunnel walls, and a third machine portion partially supports the curing concrete. The cost of tunnel lining according to the techniques of the present invention has been substantially reduced, and the machine may be placed directly behind a tunnel boring machine.

Abstract: A ground boring tool known as a mole is fitted within its conical head (1) with a pneumatic-powered rotatory vibrator (8) which generates severe radial vibrations. As a result the progress of the mole through resistant ground is speeded or made possible. The mole also may be used for upgrading existing ducts with or without the destruction of an existing lining to such ducts. For destruction of existing linings elongate ridges (16) may be positioned on the surface of the cone.

Abstract: The present invention concerns a rock cistern or tunnel. The inner surface of the wall structure of the rock cistern is a tightly sealing lining. The supporting layer consists of a steel-reinforced water-tight sprayed concrete layer. Between the blasted rock surface and steel-reinforced water-tight sprayed concrete layer there is a sprayed concrete layer permeable to water, serving as a groundwater-conducting layer. In the sprayed concrete layer permeable to water, subdrain pipes have been placed. The tightly sealing lining consists of plastic, steel, fibre concrete or equivalent.

Abstract: A process for establishing a clear, generally horizontal borehole path in a subterranean formation includes drilling a generally horizontal borehole using a drill pipe, drill bit and an uphole drilling device and lubricating the drill bit and pipe by pumping a mud down the center of the drill pipe in sufficient quantity to carry cuttings, created by the drilling, from the horizontal borehole using a mud capable of creating a cake on the borehole wall. Throughout drilling of the borehole, the total solids content of the efflux is adjusted to preselected levels and recirculated through the drill pipe to continually create the borehole wall cake. After drilling, the drill bit and drill rod are removed and the drilling bit replaced with a casing shoe. Thereafter, the drill pipe is reinserted into the borehole with a liner therein.

Abstract: A circular heading machine for excavating tunnels by advancing a machine in stepwise fashion and erecting tunnel supports, having an elongate machine body at the forward end on which a forwardly directed cutter boom is mounted. Rams advance the machine body in stepwise fashion acting against grippers and a profile ring limits peripheral movement of the cutter boom to form an accurate profile. A gathering apron is provided at the forward extremity of the machine body. The cutter boom is mounted on a sliding carriage longitudinally movable on and independently of the machine body and a hood overlies the apron. A cage structure extends rearwardly from the hood structure and surrounds the body cutter and sliding carriage and tunnel support erecting members are provided externally of the cage structure, directly behind the hood structure. The hood is a semi-circular member supported by hydraulic rams for height adjustment.

Abstract: An apparatus for making a tunnel lining from concrete in a single operation with a tunnel excavator comprises a tunnel lining form consisting of a plurality of tunnel lining form segments and a form front adjacent the tunnel excavator and a tunnel lining circular space between the form and the ground. In order to heat the concrete as it is pumped into the tunnel lining circular space to accelerate hardening, transmitting antennae for electromagnetic radiation are mounted in the tunnel lining form segments and/or the feed pipes for the concrete. Similarly a process for making a tunnel lining from concrete comprises pumping concrete into the tunnel lining circular space and accelerating the hardening of the concrete by heating it with electromagnetic radiation. The tunnel form is rapidly repositioned after the concrete being hardened reaches a sufficient strength.

Abstract: This invention provides an apparatus for construction of an underground or aboveground continuous article (98) which has at least one bore (99). In case the article is made underground, the apparatus has at least one rotary cutter (51) for excavating the earth and a spoil discharge device which separates water from the spoil (97) and discharges separately the water and the dewatered spoil, respectively. The apparatus has at least one electric heater (49) for heating material (95) passing a space (67) disposed between a tubular member (45) and a bore forming member (46).

Abstract: A novel method of underwater tunnel construction is provided which comprises the employment of a double-layered flexible mold or form and the introduction of both an inert and a reactive fluid into spacings of the mold so as to produce both the shape and the basic structure of the designated tunnel. Upon consolidation of the reactive fluid, the inert fluid will be withdrawn and air is filled in to provide the tunnel spacing for further finishing work and normal function of the tunnel. When completed, the designated tunnel basically consists of a sandwich-like structural body having a least an inner and an outer layer of impermeable fabrics and sandwiched within these fabrics a relatively thick layer of consolidated mass such as concrete which constitutes the main structure or walls of the tunnel. A second layer of consolidated mass may be provided through the use of a third and outer fabric and the corresponding introduction of the reactive fluid into the enclosed spacing thereof.

Abstract: The manufacture of extended, inaccessible holes for underground ducts, conduits and the like is performed by a closed construction process, wherein the preferably remotely-controlled excavation is performed and following that a structure is installed which is employed as the product duct, conduit or the like. The installed structure is provided by injection of an injection material under pressure into an annular space between a form following the excavating apparatus and the ground to manufacture at least one endless inner wall for the hole which then serves as the underground duct, conduit or the like. The novel apparatus of this invention correspondingly comprises a form following the required excavation mechanism conformed to form an annular space between the form and the ground, that form having a form front closing the form and at least one inlet therein for injection of an injection material into the annular space.

Abstract: A form front positioned between the shield of a tunnel excavator and a tunnel-lining form movable relative to both the shield and the tunnel-lining form. The form front comprises an annular support positioned with clearance space from the shield and the tunnel-lining form, wherein the annular support has a lipped inner seal pressing on the tunnel-lining form and is held thereto by pressure adjacent the inner covering surface of the annular support, and also has an outer seal held under pressure against the shield adjacent the outer covering surface of the annular support.

Abstract: A tunneling machine with a leading ring, a follower ring, an overlapping joint connection between the leading ring and the follower ring, a pressure ring, advancing piston/cylinder assemblies, and a roll correction device. The advancing piston/cylinder assemblies are distributed about the shield circumference, and they are connected on the one hand by the way of linkages to the pressure ring, and on the other hand they are supported at the leading or shield ring. The roll correction device has a roll correction ring which is arranged in the leading ring, and the roll correction ring can rotate with respect to the leading shield. The roll correction ring is also supported by a thrust-absorbing bearing. The advancing piston/cylinder assemblies are movably joined at the roll correction ring, and are indirectly supported at the leading ring.

Abstract: A shield tunneling machine in which a segment holding member is movable through a lifting beam in the radial direction of a shield frame so that the segment holding member holds a segment and sets it at a predetermined position in the circumferential direction of a tunnel within the shield frame; and an end balancer is pivotably connected to a base or root balancer which in turn is slidably mounted on the lifting beam so that the segment held by the segment holding member is correctly set at a predetermined position while the posture of the segment is suitably adjusted, whereby the erection and assembly of segments can be easily accomplished.

Abstract: A tunneling machine of the type having a leading shield, a trailing shield, an annular form connected to the trailing shield by respective cylinder units for the emplacement of the concrete behind the machine and cylinder units for relatively advancing the leading and trailing shields, is also equipped with a telescoping shield assembly with its own set of cylinder units so that the concrete emplacement can be decoupled from the advance of the cutting head on the leading shield.

Abstract: A movable wall delimiting a space into which concrete is pumped between a shield lining a tunnel wall and an inner form is advanced by the concrete pressure relative to the shield. This movable wall can be braced by adjustable spring force relative to the shield.

Abstract: A tunnel casing is formed by cylindrical casing sections whose proximal flanges are not only bridged by the usual drawbolts tending to pull the casing sections toward one another, seals and centering elements, but also are provided with wedge or hydraulic spacers which can fix the gap widths at the respective joints by hydraulic or wedge blocking to take up pressure forces which cannot be sustained by the drawbolts.

Abstract: A method and apparatus for constructing an enlarged tunnel in a portion of a predetermined region of an existing tunnel. A circumferentially enlarged portion is excavated to define a starting base for a shield machine. The shield machine is positioned in the circumferentially enlarged portion and advanced forward along the existing tunnel in order to enlarge the circumference in the predetermined region of the existing tunnel. A section of a tubular liner lining the existing tunnel is broken and removed therefrom. Thereafter, the resultant enlarged tunnel portion is lined with segments.

Abstract: The invention provides a tunnel lining and a method of constructing the tunnel lining by aligning prestressed resilient lining panels of uniform thickness, such as plywood sheets, where longitudinal edges of the panels abut to form a ring. The longitudinal edges of the panel correspond to, and impose thrust against a second longitudinal edge of an adjacent panel. The thrust causes bending of the panels to form an arc about the longitudinal axis of the panels and to cause internal stresses within the ring to counteract loads applied at the exterior of the panels. The ring can consist of multiple layers of panels.