Abstract: A underground support includes a first row of panels, and a second row of panels configured to be secured to the first series of panels to define an interior space for receiving construction aggregate or concrete. Each panel of the first row of panels and the second row of panels includes a body having a top edge, a bottom edge positioned opposite from the top edge, a left edge, and a right edge positioned opposite from the left edge, with the top edges of the panels of the first row of panels configured to abut the bottom edges of the panels of the second row of panels.

Abstract: A cable retention and release mechanism includes a cable gripping device including a cable passage. A cable extends through the cable passage. A cable gripping device collar is movably coupled around the cable gripping device. An outer cable gripping device surface is seated against a cable gripping device receiving inner surface preventing movement of the cable gripping device relative to the cable gripping device collar. The cable gripping device receiving inner surface clamps the cable gripping device on the cable and prevents sliding movement of the cable. A jack is movably coupled with the cable gripping device collar. In a first engaged position the jack is engaged against the cable gripping device proximal end. In a second engaged position the jack unseats the outer cable gripping device surface from the cable gripping device receiving inner surface and releases the clamping of the cable.

Abstract: A method for designing and fabricating a mine seal includes determining an initial thickness for a mine seal based on a predetermined underground opening, developing and solving a numerical model for response of the mine seal upon application of a blasting pressure, and determining whether the mine seal meets predetermined design criteria. A mine seal having a minimum seal thickness may be fabricated after determining the mine seal meets the predetermined design criteria.

Abstract: A civil engineering work (1) comprising a front face (9), a facing (3) having a back surface (32) and a front surface (31) that is substantially the same as said front face (9) of the work, a fluid-tight covering (4) on the back surface, a fill (2) arranged behind said fluid-tight covering (4), and an anchoring device (6) ensuring a mechanical linkage between the facing (3) and the fill (2), with said facing (3) comprising a cavity (5) inside of which a portion of the fluid-tight covering (4) is arranged to form a recessed space into which is inserted an anchoring element (16) that is a part of said anchoring device (6), and a method for implementing such a work.

Abstract: An underground mining apparatus includes a mining head for moving through underground material to extract material in its path and form a passageway behind the mining head as it advances. An elongate structure extends along the passageway to the mining head and provides a path for delivering the extracted material to ground surface. A shroud is positioned about the elongate structure for supporting engagement with the periphery of the passageway and to provide a space through which the elongate structure can move. The shroud has a cross-sectional shape corresponding generally to the cross-sectional shape of the passageway formed by the mining head. A method is also disclosed.

Abstract: An apparatus for supporting communication equipment in an underground mine includes a pair of vertically extending laterally spaced and substantially parallel elongate members, a pair of horizontally extending members, each depending from and extending outwardly from proximate a lower end of a respective elongate member a distance approximately equal to a thickness of a power supply, an upper shield member attached to and extending outwardly from proximate an upper end of the pair of elongate members in the same direction as the pair of horizontally extending members, extending a distance approximately equal to a depth of power supply and having a width approximately equal to a width of the power supply, and a flexible sheet of material disposed over the pair of elongate members from below the upper shield to above the pair of horizontally extending members that is held in place by the communication node.

Abstract: Segments are linked in the circumferential and pipe length directions to assemble a rehabilitating pipe inside an existing pipe in order to rehabilitate the existing pipe. A plurality of nuts are secured to the segments along the circumferential direction thereof. A fastening member having a screw part is provided which is screwed into the nut to fasten a first segment to a second segment to which the nut is secured, thereby linking the first and second segments in the pipe length direction thereof. The position of the nut in the first segment is offset as viewed in the circumferential direction from the nut position of the second segment. The arrangement of the fastening members and the nuts is staggered as viewed in its entirety. This allows the connection strength of the segments in the pipe length direction to be made uniform.

Abstract: A liner plate structure, system and method is provided for lining of mine shaft bores, tunnels and the like. The liner plate structure includes a primary plate portion and at least one flange disposed at a side edge of the primary plate portion. A thermoplastic fusion element extends along an exterior surface of the flange. A liner structure within a shaft or tunnel includes at least first and second liner plate members assembled together, the liner plate members formed of metal plate material having respective metal surfaces in contact with each other along a plate joint. A thermoplastic fusion seal arrangement is located along the plate joint.

Abstract: In an existing pipe rehabilitating method according to an embodiment, a profile strip (2) for lining an existing pipe (10) is shaped using a thermoplastic resin, joint portions (21) are provided at both end portions in a width direction of the profile strip, and the profile strip (2) is inserted into the existing pipe (10) and is helically wound in the existing pipe (10). The joint portions (21) of adjacent windings of the profile strip (2) are interlocked with each other, thereby forming a rehabilitating pipe (20). Also, the profile strip (2) of the rehabilitating pipe (20) is deformed by a heating step in which the profile strip (2) is subjected to a heating process by a heating means so as to conform a shape of a curved portion (13) of the existing pipe (10), thereby integrating the profile strip (2) with an inner peripheral surface of the curved portion (13) of the existing pipe (10).

Abstract: Segments are coupled in the circumferential and lengthwise directions to assemble a rehabilitation pipe inside an existing pipe. Thereafter, a pipe-lining material impregnated with a liquid curable resin is inserted into the assembled rehabilitation pipe, and the curable resin is cured in a state in which the pipe-lining material is pressed against the internal circumferential surface of the rehabilitation pipe. This allows the internal circumferential surface of the rehabilitation pipe to be lined with the lining material. With such a configuration, a rehabilitation pipe composed of segments and a rehabilitation pipe composed of a pipe-lining material are constructed to provide a self-supporting pipe inside the existing pipe with dramatically improved strength that will incur little damage or breaking even when an earthquake occurs or another large impact is applied.

Abstract: A linking tool links segments for a rehabilitating pipe for rehabilitating an existing pipeline. The segment is integrally formed at least from an internal surface plate that constitutes the inner circumferential surface of the rehabilitating pipe, and side plates that have an insertion hole formed thereon and are disposed on both sides of the internal surface plate so as to extend in the circumferential direction of the rehabilitating pipe. The linking tool includes a tubular linking pin that is separable into pin halves and can be inserted into the insertion hole in the side plate of a first segment with a part of the linking pin remaining outside the first segment. The linking tool further includes a separating pin that can be inserted into the linking pin to separate the linking pin into the pin halves and press them against the first segment for anchoring thereto.

Abstract: A rehabilitating pipe is laid inside an existing pipe to rehabilitate the existing pipe. Support members are intergrally connected to an inner wall surface of the existing pipe so that loop portions of the respective support members extend from the inner wall surface of the existing pipe. The rehabilitating pipe is assembled inside of the existing pipe by mutually coupling segments of the rehabilitating pipe in a longitudinal direction of the existing pipe by inserting coupling members through connecting through-holes of the segments and through the loop portions of the respective support members to thereby support the assembled rehabilitating pipe so that the rehabilitating pipe remains inside of the existing pipe after assembly to rehabilitate the existing pipe.

Abstract: A segment for rehabilitating an existing pipe has an integral structure comprised of an inner plate having an inner circumferential surface that is planar or curved with a prescribed curvature, two side plates provided upright on each side edge of the inner plate, and two end plates provided upright on each end edge of the inner plate. At least one rehabilitating plate comprising a resin sheet covers one of an outer circumferential part of the segment facing the existing pipe and the inner circumferential surface of the inner plate.

Abstract: A pier-repairing and reinforcing panel is used in a method of repairing and reinforcing a pier. The panel includes locking members, locking ribs, reinforcing ribs, and clips. The method includes the steps of: installing a watertight caisson around a pier and removing water from the gap between the caisson and pier. Impurities are removed from the pier's surface, and a plurality of panels are installed around the pier while sealing the junctions of the panels. A plurality of reinforcing steel bars are arrayed in the gap between the pier and panels, and the panels are then affixed to the steel bars or the pier using anchor bolts. The gap between the pier and the panels are then filled with concrete. The pier is effectively repaired and reinforced while separating the reinforced concrete from water, thus protecting the concrete and steel bars for a desired lengthy period of time.

Abstract: The top arch overfilled system defined in application Ser. No. 10/102,921 is formed of precast arch elements which are formed and shipped in a use orientation. The precast arch elements can include arch footings and the system can include a plurality of precast arch elements which can be tied together. The arch elements can also be prestressed.

Abstract: A method of repairing and reinforcing a pier using stones. The method includes installing a watertight caisson around a pier and removing water from the gap between the caisson and pier prior to repairing the pier. The method can also include removing impurities from the pier's surface; arraying a plurality of reinforcing steel bars around the pier; laying stones outside the arrayed steel bars while fixing the stones to the steel bars or the pier, and filling the gap between the pier and the stones with concrete.

Abstract: The invention relates to a tubbing (2) for a tubbing ring (1) used in underground tunnel works in which a front tubbing face (4) and a rear tubbing face (5) are provided. At least one tubbing face (4, 5) is provided in the shape of a spherical shell.

Abstract: An earth overfilled arched structure includes a shallow arch spanning a clear space. The sides of the clear space are formed by curved or straight walls. Solidified zones of earth material (backfill or in situ) against the springs of the arch and/or behind the walls form foundation blocks which are in intimate contact via arch footings with the springs of the arch and/or with the upper part of the sidewalls in such a way that the arched structure delivers most or all of its support forces into the foundation blocks. These, due to their size and weight, transfer and spread the support forces to the subsoil so that displacements, especially in the horizontal directions, are minimal.

Abstract: A mine stopping installed in a mine passageway includes a plurality of elongate panels extending generally vertically in side-by-side relation from a floor to a roof of the passageway to at least partially close the passageway. A generally horizontal elongate brace extends generally between the walls of the passageway adjacent to the panels. A generally vertical column extends from the floor to the roof and is adapted for reinforcing the brace. Braces and anchor beams for stoppings are also disclosed.

Abstract: The disclosure is for an underground structure liner based upon an inflatable liner structure. An acid resistant layer is the innermost layer of an inflatable liners and the liner is coated with epoxy resin on its outermost surface, the surface which contacts the existing walls of the underground structure. The outermost coated surface of the liner is constructed with a fibrous fleece layer for better retention of the epoxy and better adhesion of the epoxy to the walls of the underground structure. An added feature of the liner is a structure which also seals the liner to pipes entering the underground structure.

Abstract: A mine stopping installed in a mine passageway includes a rigid wall extending across the passageway to close the passageway. The wall includes a first wall section extending from one side of the passageway at a first angle and a second wall section extending from an opposite side of the passageway at an oblique angle relative to the opposite side such that the wall sections are arranged in a non-coplanar, non-parallel relationship with respect to one another. A method of installation is also disclosed.

Abstract: The apparatus is an underground structure liner based upon an inflatable liner structure. An acid resistant layer is the innermost layer of an inflatable liner, and the liner is coated with epoxy resin on its outermost surface, the surface which contacts the existing walls of the underground structure. The outermost coated surface of the liner is constructed with a fibrous fleece layer for retention of the epoxy and adhesion of the epoxy to the walls of the underground structure. An added feature of the liner is a structure which also seals the liner to pipes entering the underground structure.

Abstract: A mine stopping installed in a mine passageway having air flowing through the passageway in a first direction includes a rigid wall extending across the passageway to close the passageway and an opening in the wall to permit the passage of air therethrough. The wall extends between the opening and one side of the passageway at an oblique angle with respect to the direction of air flow through the passageway whereby air flowing through the passageway strikes the wall at the oblique angle thereby to reduce the dynamic air pressure exerted on said wall.

Abstract: A method of sealing off a mine passageway. The method involves installing a plurality of vertical panels side by side across the passageway to form a stopping. The stopping has gaps between adjacent panels and gaps between the panels and adjacent mine surfaces defining the mine passageway. The method further comprises holding an injector in or closely adjacent the gaps, and injecting a fluent sealing material under pressure into the gaps to form a seal.

Abstract: A construction method for widening road, superhighway or railway tunnels, without interrupting the traffic flow includes a first stage of excavation; in steps, of the ground between the theoretical profile of the future widened tunnel and that of the original tunnel, after having reinforced the ground between the theoretical profile of the future widened tunnel and that of the original tunnel by reinforcement operations on the face, and a second stage in which the final lining, comprising one or more arches of prefabricated segments is placed close to the face.

Abstract: The invention relates to a concrete lining element for a drilled tunnel, which element is formed as a ring segment and is internally reinforced, and a plurality of which ring segments can be joined together to form a ring, and a plurality of rings can be joined to form the lining for the drilled tunnel and wherein, in order to couple adjacent rings at the intermediate ring joint, each element is provided at one side bordering the ring joint with at least one projection, and at the opposed side with a corresponding recess to admit the projection of an adjacent element. The height of the projection, respectively the depth of the recess on the respective side is between 30 and 60 mm, and the projection, respectively the recess at the transition from its top, respectively its bottom to its side walls, possesses rounded comers, having a radius of rounding of between 5 and 50 mm.

Abstract: A ventilation overcast comprises a frame member that defines a structure having a substantially inverted U-shape with first and second opposed side wall portions and a roof portion. A curtain member having a plurality of longitudinal corrugations therein is positioned adjacent the frame member so that a bottom portion of the curtain member contacts the floor of the mine. The longitudinal corrugations allow the curtain member to be crushed when subjected to floor heave.

Abstract: A method of manufacturing a tunnel (10) or shaft lining or pipeline of segments (12), wherein each segment (12) comprises a concrete body (11) having an extrados (13) surface, an intrados (14) surface and first and second ends (15, 16) and first and second sides (17, 18), the ends (15, 16) and sides (17, 18) providing edge portions, the segments (12) being adapted to be connected to further similar segments (12) with edge portions adjacent edge portions of adjacent segments (12), the method being characterized in that the method includes enveloping the ends (15, 16) or sides (17, 18) of at least a pair of segments (12) in a reinforcing material as the concrete is cast, and once the concrete has cured, connecting the segments (12) together with one of each of their enveloped ends (15, 16) or sides (17, 18) adjacent, and sealing between the enveloped ends or sides.

Abstract: A segment 20 has segment units 22 obtained by dividing a cylindrical body having an appointed length into four sections along the circumferential direction. The segment units 22 are provided with a segment body 22a, a porous concrete layer 22b, water intake pores 22c, and clogging members 22d. The segment body 20a is constructed of a cast iron plate or steel plate and has an inwardly recessed portion on its outer circumferential surface. The concrete layer 22b is a porous material having water permeability, and is filled and solidified in the inwardly recessed portion 201a. The water intake pores 22c are formed on the flat bottom of two recessed portions 201a so as to penetrate the bottom, and are provided in a plurality along the circumferential direction with an appointed interval.

Abstract: A material and method is provided for lining man-entry sized pipes and securing the lining to the pipe. The lining comprises a plurality of adjacent, unplasticized polyvinyl chloride panel segments circumferentially curved within the pipe, each including an interior channel through which grout may be injected. Upon the grout's curing, the grout provides strength and support for a second layer of grout injected into an annulus between the pipe's inner surface and an outer surface of the lining.

Abstract: A liner strip for lining an interior surface of a pipe including an extended plastic strip having T-shaped formations with reinforcing fibers integrally extruded in the liner strip for increasing the liner stiffness and tensile strength to resist forces imposed on the liner during installation.

Abstract: A mine stopping comprising a wall extending across a passageway in a mine to close the passageway. The wall has an opening therein. A door is hinged adjacent the opening for swinging between a closed position in which the door closes the opening to inhibit the passage of air therethrough, a first open position in which the door is moved in one direction away from the closed position, and a second open position in which the door is swung in an opposite direction away from the closed position. The door is movable to either of the first and second open positions when the door is subjected to substantial concussive air pressure thereby to permit concussive air to pass through the opening in both directions.

Abstract: A wall surface of a structure to be rendered antifouling is covered with antifouling panels caused to firmly adhere thereto and fixed. Not only can this work be conducted easily and quickly but also part of the antifouling panels can be easily replaced. The disclosed antifouling wall structure and method of constructing the antifouling wall are characterized in that antifouling panels each comprising a base material layer and, formed thereon, an antifouling paint layer are arranged on a wall surface of structure to be rendered antifouling so that the antifouling panels have their side of antifouling paint layer brought into contact with water and detachably fixed by means of fastening members.

Abstract: A ventilation overcast may comprise a plurality of support columns, each of which has an upper end and a lower end. A plurality of cross beams are connected between the upper ends of each of the plurality of support columns so that the support columns and cross beams define a generally rectangular structure having two opposed side wall portions and a roof portion. A curtain member having a plurality of longitudinal corrugations therein is positioned between the lower ends of adjacent support columns located on the same side wall portion of the ventilation overcast so that a bottom portion of the curtain member contacts the floor of the mine. The longitudinal corrugations allow the curtain member to be crushed when subjected to floor heave.

Abstract: With a method for constructing a water intake pipe, a vertical shaft 10 is constructed, and a shield tunnel 12 is constructed by causing a shield driving machine to advance from the vertical shaft 10 toward a seashore by breaking the wall of the vertical shaft 10. The tunnel 12 becomes a water intake pipe after the tunnel is constructed, and is built by annularly assembling segments 14 one after another at the rear side of the shield driving machine in line with the advancement thereof. Two types of segments 14, RC segments 18 and ductile segments 20, are used. The segments 20 are provided with water intake pores clogged by clogging members. After the tunnel 12 is constructed, workmen enter the shield tunnel 12 with compressed air supplied thereinto, and remove the clogging members of the ductile segments 20.

Abstract: One end of a circumferential joining end surface 2 of segments 1 which are joined together in the circumferential direction of an excavated tunnel is made the male side circumferential joining end surface 2a on which a male coupler 4 is provided, and the other end is made a female side circumferential joining end surface 2b on which a female coupler 5 is provided. On a base plate 7, a bolt 10, which provides an engagement part 16 comprising a flat washer 13, a disc spring 14, and a head 15, is erected, and made a male coupler 4. An engagement plate 23, formed by a notch 22 which engages the bolt 10, and is inserted and engaged between the base plate 7 and the engagement part 16, and tightly held by the elastic force of the disc springs 14, is made the female coupler 5.

Abstract: A method for controlling deformation of an erected structural metal plate culvert or underpass during backfilling of the erected structure comprises: building progressively a reinforced earth retaining system on each side of the erected structure by alternately layering a plurality of compacted layers of earth with interposed layers of reinforcement to form reinforced earth on each side of the erected structure and securing to each side of the structure each said layer of reinforcement in the reinforced earth, whereby such securement of each said layer of reinforcement to said structure controls deformation of the erected structure during backfilling with the reinforced earth on each side of the structure. The layer of reinforcement may be a plurality of strips extending away from the structure, or a reinforcement mat of interconnected rods.

Abstract: Tunnel liners are formed from panels of arched sheet material. The panels include a central portion, inclined side portions and wing portions. One of the wing portions has a hook portion and the other of the wing portions has a receptacle portion. The hook portions and receptacle portions are constructed so as to snap-fit with respective receptacle portions and hook portions of adjacent panels. Panels can thus be more easily be assembled together. Panels can also be continuously seamed together from the underside, i.e., from within an arched assembly of panels.

Abstract: The invention relates to a seal arrangement consisting of two abutting structures of concrete, steel, reinforced concrete, cast iron or other materials and a sealing section of elastomeric material which bridges and seals the gap between the two structures, in which the structures are especially segments assembled to form a tubular tunnel with the formation of transverse and longitudinal seams, where each segment preferably has at least one peripheral recess covering all the mating sides of the segments and there is in each recess a stranded sealing section which especially has strand-shaped grooves on the base side of the sealing section and/or strand-shaped channels, forming a sealing frame with corners, and the back of the sealing section has at least one strand-shaped groove to accept an emergency seal.

Abstract: This invention includes repair of an existing underground sump without the need for costly and time consuming excavation. A plurality of liner-forming pieces are placed inside the underground sump to create a liner preferably substantially conforming to the interior dimensions of the sump. The pieces are joined together to form a unitary containment shell by first taping and then using fiberglass cloth and fiberglass resin. A layer of gel-coat is applied to the surface of the shell to create a fluidtight containment chamber within the sump. Some of the liner-forming pieces can have openings formed therein to accommodate the pipe entries corresponding to those in the sump.

Abstract: The polymer and fabric composite includes at least two polymer sheets with fabric attached covering substantially one side of the polymer sheets. In one embodiment, one of the sheets has a strip of polymer along at least one edge not backed by the fabric. This edge forms a lip that can be attached to another polymer sheet to form a strong bond between the two polymer layers. In another embodiment multiple polymer sheets are prepared with the fabric backing covering substantially one side leaving a lip of polymer for attachment along an edge of each of the polymer sheets. Additional similarly prepared polymer sheets with a polymer lip and fabric backing can be attached to manufacture the desired size of continuous composite.

Abstract: A water-resistant mine bulkhead or seal is provided in which two walls are constructed across the mine entry. One of the walls is constructed in layers. After a lower portion of the layered wall is erected, a first layer of gravel is provided between the walls. The gravel is then saturated with a binding material such as a polyurethane composition so that the binding material fills the voids between the gravel particles. Additional layers of gravel subsequently saturated with the binding material are provided until the gravel layer is equal in height to the lower portion of the layered wall. The layered wall is then further erected and the process continues until the layered wall is completely constructed and the binding material-saturated filler material emplaces the mine roof. Finally, the exposed surface of the exposed wall is coated with a sealant. Alternatively, the binding material and filler material can be pre-mixed and injected into the space between the two walls.

Abstract: A system for and process of relining transport lines such as sewerage pipelines having an inner tubular thermoplastic inliner, a tubular thermoplastic preliner disposed within the pipeline to be restored. The inner inliner being disposed concentrically and internally of the preliner and having on its exterior means to fix a defined annular space between the inner inliner and the preliner and for anchoring the inner inliner positively in a hardenable composition to be introduced in the annular space between the inner inliner and the preliner.

Abstract: An element for lining the interior surface of a tunnel, which comprises a composite panel in which a fibrous layer is laminated over a hard substrate, and a fluoropolymer surface layer is laminated over said fibrous glass layer.

Abstract: The invention relates to a constructional element such as a tunnel lining, part of which is shown in the drawing, comprising adjacent segments which have facing surfaces between which there is a joint which is physically deformable under load. The joint comprises a toroidal body or tube of substantially circular cross section received in complementary or semi-circular facing recesses in the surfaces respectively, and comprises a flexible material such as polypropylene and which means in the form of a nozzle for gaining access to the interior of the body. The body is initially filled with a fluid, which could be a liquid or gas, through the nozzle, which can then be maintained in the body by closing the nozzle as by a valve.

Abstract: A general segment 20 which is propelled and set in an excavated hole by a propulsion excavating machine, and a flexible segment where flexible members 4 and rigid ring members are alternately installed and connected inside the skin-plate 7 provided on the outer periphery side of the side rings 5 having the same thickness as the general segment and a thrust-receiving member 9 is provided inside the flexible portion, are propelled and set by the propulsion excavating machine and then secondary coating concrete 30 including a secondary watertight band 15 is applied to said side ring. As a segment for a shield tunneling method, the flexible segment appropriately provides flexibility to quickly cope with earthquakes and uneven settlement. The flexible segment may be handled in the same manner as a standard general segment during excavation work, providing excellent application potential.

Abstract: An insulating liner system especially adapted to railroad and highway tunnels to eliminate ice buildup on the tunnel crown, walls and roadbed caused by water leakage from the tunnel face. The insulating liner system includes a modular assembly of insulating panels, each comprised of a sheet metal or plastic face adherred to a preformed insulating foam core which is then waterproofed by coating all exposed faces of said core with an elastomeric or similar waterproof film. The ability of both the foam core and the elastomeric coating to stretch allows the panels to be fabricated and shipped in a flat configuration and formed to the tunnel arch during installation. The system also includes an insulating base with enclosed water drainage system, means of joining individual panels with waterproof joints, methods of supporting the liner system to the tunnel walls and a means of equalizing piston-effect pressures on the front and back faces of the liner system.

Abstract: A slipliner for renovating a semi-elliptical conduit such as a masonry sewer line. The bottom of a semi-rigid cylindrical liner pipe is split longitudinally and a floor panel is mounted across the bottom of the pipe to spread the edges of the cut. This bends the lower side walls of the pipe outwardly so that these correspond to the generally vertical side walls of the conduit, while the upper portion of the pipe remains generally cylindrical so as to correspond to the top wall of the conduit and the floor panel corresponds to the generally horizontal bottom wall of the conduit. The slipliner of the present invention is thus much more closely matched in shape to the semi-elliptical conduit than would be a conventional, cylindrical liner.

Abstract: A tunnel barrier system for lining the interior surface of a tunnel cavity includes a first panel in facing engagement with and affixed to a first impermeable membrane. A second panel is in facing engagement with and is affixed to a second impermeable membrane. The second panel is positioned adjacent to but spaced apart from the first panel to form a cavity between the panels. A filling material is positioned within the cavity. A third impermeable membrane is in facing engagement with both the first and second impermeable membranes and extends across the cavity such that the first panel, the second panel and the cavity are rendered airtight and watertight.

Abstract: A mine door system adapted for installation and a passageway in a mine, comprising a door frame adapted to be installed in the passageway and defining a doorway spaced below a ceiling of the passageway and mine door hingedly mounted on the door frame for movement between open and closed positions. The system further comprises a top panel structure for substantially closing the space between the door frame and the ceiling of the passageway, the top panel structure being readily contractible heightwise of the passageway without loss of its structural integrity to accommodate a convergence of the ceiling and floor of the passageway without any substantial heightwise deformation of the door frame.