Abstract: A system and apparatus for forming a wall on a footing. U-shaped and H-shaped channels coupled at their sides by rigid links hold foam panels in a desired spaced relationship. The channels and panels are stacked to a desired height, and concrete is poured between the channels and panels where it hardens to form a structural wall. The planar surfaces of the U-shaped and H-shaped channels enable the channels to be extruded, thereby substantially reducing channel production costs. Furthermore, widely available conventional foam panels are used, reducing panel production costs.

Abstract: An improved wall stud utilized in framing structures, the wall stud including core elements and insulative materials enclosed within C-shaped frame members. The walls studs can be aligned and secured in a metal track mounted on the top and bottom ends of the wall studs. The wall studs provide good insulation, support, and easy access for the installation of electrical and plumbing equipment.

Abstract: The structure comprises, in combination, lattice elements (1) with successive sides (1A) inclined in opposite directions; longitudinal connecting pieces (1B) and partial longitudinal connecting pieces (1C) for the joining of successive lattice clients (1) in alignment with each other; links (3) for connection between longitudinal connecting pieces (1B, 1C) of adjacent lattice elements (1) which have been brought together; components for mechanical connection (5, 7) between successive lattice elements (1) and/or components for mechanical and electrical connection (24, 26) between successive lattice elements; adaptors (61, 71) which may be fitted to said longitudinal connecting pieces (1B, 1C) for lighting or consumer units to be combined with the reticular structure.

Abstract: A space truss is constructed of a pair of plane trusses. Each of the plane trusses is constructed of an upper and lower chord member fixedly connected with each other through a strut member interposed therebetween. The thus constructed plane trusses are oppositely disposed from each other in a condition in which the strut member of each of the plane trusses are interposed between the thus oppositely disposed plane trusses, the upper chord members of the plane trusses are closely disposed together, and the lower chord members of the plane trusses are spaced apart from each other. A sheet steel is fixedly connected to the space truss through a hanging hook to form a composite-type space truss. Any of these space trusses are embedded in concrete in the factory to form a precast reinforced concrerte slab.

Abstract: A truss member for the erection of a building structure being fabricated in twenty eight foot lengths having top and bottom full length 2.times.4 members having intermediate angled hardwood members with spaced vertical hardwood members and plywood full length at each side thereof and at either outer side the full length thereof angled iron members and at each end thereof transverse bolts forming a unitary parallel metal truss box beam member requiring no bearing walls in providing overhead support reducing the cost of fabrication relative to a prior art truss member on the order of fifty percent and reducing the time and cost of erecting a frame structure by substantially a like amount of savings.

Abstract: A deck plate includes a number of trusses arranged in parallel and rigidly secured to a base member, each of the trusses includes one upper reinforcing bar and two lower reinforcing bars arranged to provide a triangle transversely, and two corrugated reinforcing bars each having a series longitudinal triangle waves and adapted to be rigidly secured to the upper reinforcing bar and to the corresponding lower reinforcing bar respectively, so that the truss has a triangle shape transversely and can stand independently.

Abstract: A bidimensional support or tower for overhead electric energy transmission lines is formed of a flat truss structure, the stringers of which consist of at least one truss beam comprising a pair of cold-bent channel sections connected together, with their cavities facing, by means of a zigzag-bent steel rod applied by welding to the flanges of said sections. Said tower comprises two stringers connected by one or more horizontal girders, which stringers can be vertical and parallel, or else converging towards the top substantially in correspondence of the point where the loads are applied, in which latter case a vertical structural element is provided above said point. Said stringers and said vertical structural element are formed of said truss beams, positioned either singly or side-by-side.

Abstract: Stiffening elements are welded between the three rods (T1, T2, T3) of three-rod girders in uderground drift construction. Such stiffening elements consist of thee triangular wire polygons (10, 20, 30) connected to form one piece. Two of the polygons meet at the top rod (T3) to form a wire pyramid. The third wire polygon (30) is perpendicular to the plane determined by the axes of the lower rods (T1, T2). Since neither this third wire polygon (30) nor the adjacent polygon (10), which is one side of the pyramid, needs a cross-strut between the lower rods (T1, T2), a significant saving in materials combined with high resistance to bending is achieved.

Abstract: A structural member suitable for use as a joist has a web formed from a continuous rod or bar bent and shaped to define a plurality of peaks, and a flange overlying each edge of the web, with each flange formed from a continuous steel sheet bent and folded upon itself to define a socket for reception of the peaks of the web, and the wings of the flange.

Abstract: A modular constructional element comprises a truss including first and second longitudinally-extending bars joined by a plurality of transversely-extending bars such that the transversely-extending bars all occupy a first plane, and the first and second longitudinally-extending bars occupy second and third planes on opposite sides of the first plane. One of the longitudinally-extending bars has a substantial width in its respective plane to serve as a deck member in a construction utilizing a plurality of such modular elements. Such modular elements are useful in constructing various types of load-bearing structures, particularly bridges, since they are self-nesting and thereby decrease the volume for shipping, storing and handling, and also obviate the need for separate containers.

Abstract: A frame member for use as a portion of an open portable vibrated screed frame comprises a length of metal rod with metal tubes spaced along the length of the rod and bent in a zig-zag configuration such that each tube and a portion of the rod within each tube is bent together thereby providing a means for securing the frame member by welding to the tubes rather than directly to the rod material.

Abstract: A structural member that is adapted to be used as a joist purlin, or girt which is used in a roof, floor, or vertical support. The structural member comprises spaced apart, parallel chords joined to one another by spaced apart struts. Each chord is composed of a pair of angular elements having vertical flanges joined in back to back relation, the vertical flanges being joined to upper flanges which extend in opposite directions from the joined flanges and are either horizontal or inclined to correspond to the pitch of the roof.

Abstract: A modular unit for use in constructing a framework of a building consisting of a plurality of modular units in connected relationship having a floor portion with longitudinal and lateral perimeter members. The longitudinal and lateral perimeter members are joined by joists interconnecting the perimeter members and welded thereto with a corrugated metal decking overlying the joists. The joists are made from a sheet steel configuration which has been bent into a Z shaped configuration with upturned lateral portions. Plywood sheeting overlies the corrugated metal decking. The entire structure incorporates wheel wells for the enplacement of wheels so that the modular unit can be towed into place. Trusses in the roof are support the roof and are attached at the cord sections to upright structural columns. The modular unit are held together by bolts which can be later secured by welding between the perimeter members, the columns, and the truss areas.

Abstract: A truss comprises a pair of spaced, longitudinally-extending bars (or only one such bar), and a plurality of transversely-extending, or diagonal, bars occupying a common plane. One longitudinally-extending bar is disposed in a plane laterally spaced from the common plane on one side thereof, and the other logitudinally-extending bar (when included) is disposed in a plane laterally spaced from the common plane on the opposite side thereof. Such a structure permits a plurality of the trusses to be stored or transported in nesting relationship in order to occupy a minimum volume, and also permits each truss to serve as a modular element enabling any desired number of them to be secured together in building a structural framework of the desired configuration and strength.

Abstract: A fabricated open web steel joist is provided. The top and bottom chords of the joist are each formed of L-shaped angles, arranged in back-to-back relation; and the web is formed of a plurality of W-shaped pre-formed bar sections. Adjacent ends of each of the "W"'s are located between the opposed faces of the top chord. If the joist requires an odd number of panels, a "V" (a one-half "W") is inserted between two W's within the length of joint, usually at the center thereof. The joist is welded, with each end and each apex of each "W" and "V" being welded to each of the chord components. The assembly of the joist includes the jig assembly and clamping of all of the components of the joist, welding only the adjacent ends of the "W"'s (and "V", if used) and the apexes of the "W"'s in the upper chord first, inverting the still clamped assembly, and welding the now upper located apexes in the bottom chord. The welding is carried out in a vertical-up manner, in each instance.

Abstract: A prefabricated building panel comprising a plurality of longitudinally extending transversely spaced trusses, each truss comprising opposed channel members and undulating truss member joined to and extending between the channel members. One of the channel members of each truss is fastened to a sheet. A plurality of spring clips are fastened to the other of the channels at longitudinally spaced points. Each clip includes wings extending transversely of the channel. A second sheet is provided and has longitudinally extending grooves with the grooves having a configuration such that the spring clips extend into the grooves and the wings engage portions of the grooves to laterally restrain the sheet.

Abstract: A cable truss dome which is not triangulated is constructed from a plurality of cables under tension and compression members arranged in triangles having non-common sides. The cable truss dome is adapted for spanning large areas where the cables form a low shallow arch which supports a flexible membrane as a covering. The non-common vertex of the formed triangles are connected to similarly placed vertical sides of other triangles through continuous nested tension rings.

Abstract: A flanged beam with a web structure formed of a wire or strip-like member (2) bent to zigzag, meander or wave configuration, the bending spots (3) thereof being attached to the flanges (1). The specific feature of a beam performed according to the invention is that at least one flange (1) incorporates a flange section extending alongside this flange. The flange section, which is made of another material than the rest of the flange, is embedded in the flange and is cast to form a unit with it and with the bending spots (3) of the wire or strip-like member (2) which spots are connected with the flange.

Abstract: A rail assembly which is especially advantageous for use in constructing the frame and underbody of a motor vehicle comprises an upper channel member, a lower channel member and an intermediate member or web in the form of a corrugated sheet secured between the channel members and whose margins abuttingly engage the peripheral walls of the channels. Each furrow and ridge preferably comprises a planar panel portion.

Abstract: The present invention provides apparatus for composite slab construction, comprising an open web of zig-zag structure upper and lower knuckles and at least one chord united to the web to form a joist. The chord will include an upper chord comprising a sealing first bar which extends longitudinally in said joist and which has first bar which extends longitudinally in said joist and which has first and second legs. The first leg is a longitudinal, upright leg with a first face which is upright and confronts one side of the web. The second leg comprises plural longitudinally-spaced leg segments extending longitudinally throughout the length of, open spaces. The second bar extends longitudinally in said joist and includes an upright third leg having a second face which is upright and confronts the other side of the web. This second face is laterally spaced from the first leg and is in closely spaced or abutting relationship with the leg segments of the first bar.

Abstract: Rod elements with variable section, straight and discontinuous allow erection of flat and spatial structures. There are also provided flat panels with turned back edges and surface lining panels which can be associated with said flat panels as well as roofing panels which can be partially overlapped. Angle elements with L-section allow joining of several structures in miter, T and cross joints.

Abstract: A fire protective system and method for a support structure such as a truss having top and bottom chord members, web members extending between the top and bottom chord members and connector plates for connecting the respective ends of the web members to the top and bottom chord members. Fire protection is provided by an elongated metal member having a base portion and a pair of flanges projecting upwardly from the base portion to form a channel. The bottom chord member is received within the channel so that the flanges extend at least partially upwardly along respective opposite sides of the bottom chord member and are in contact therewith. The web members are preferably comprised of V-shaped metal webs having a central toothed connector plate, a pair of elongated arms diverging outwardly from the central connector plate and a pair of toothed connector plates integrally formed on respective ends of the arms opposite the central connector plate.

Abstract: A structural strut having at least one surface of generally U-shaped cross section and being formed with a pair of upstanding side walls having opposed tapers. The side wall tapers of the strut shift or skew the neutral axis of the member in proportion to the relative side wall dimensions. In this manner, the strut may be used to comprise a load bearing member having a neutral axis selectively slanted to a position maximizing structural loading efficiency and interconnection. The ends of the strut are further formed of substantially planar construction for flat abutment and welded attachment to cross members of a truss thereby eliminating conventional gusset plates. The structural strut may also be constructed from a pair of such U-shaped channel sections secured back-to-back with the tapering flanges complementally positioned opposite one another for selectively shifting the neutral axis of the resulting I-beam.

Abstract: A lining-frame for a gallery or tunnel comprises two planar latticework trussed arches, each comprising an inner belt (3,4) and an outer belt (1,2) interconnected by a zig-zag rod chain (5,6). The arches are fixed parallel to one another by planar connector elements (81a,82a:81b,82b).

Abstract: A composite floor system includes a plurality of joists, each having a top and bottom chord and a web in the space between the chords. The top chord is formed with a pair of horizontally extending legs and at least one vertical leg. The top of the web is attached to the bottom surface of the top chord. Metal decking is supported by the horizontal legs of the top chord of adjacent joists and a concrete slab is poured on the decking and encloses the vertical leg of the top chord.

Abstract: A bridging system (50) for steel joists (56) comprises fasteners (52) secured to the chords (54) of the steels joists (56) by welding. Bridging members (60) comprise the lengths of angle iron having fastener receiving holes (62) formed therein at equally spaced intervals. Selected fastener receiving holes (62) of the bridging members (60) are engaged with the fasteners (52), and the bridging members (60) are mechanically retained in engagement with the fasteners (52). The fasteners (52) may comprise steel dowels, in which case the bridging members (60) are retained by retaining rings (74), or threaded members, in which case the bridging members (60) are retained by nuts (76) threadedly engaged with the fasteners (52).

Abstract: A plurality of V-shaped metal web members serve to interconnect two elongated wooden members for forming a truss or joist assembly. The two elongated wooden members are arranged so as to extend parallel to each other with a spacing therebetween. The metal web members are placed in the spacing between the wooden members and have their extremities connected to the wooden members. Each of the metal web members has connector nail plates located both at its apex and at each of its extremities. Struck out from each connector plate are a plurality of pairs of teeth with each pair of teeth leaving a corresponding slot between them. All of the teeth extend from the same face of the metal web member. Each of the connector plates at the two extremities is connected to the apex connector plate by a leg member. Each of the legs has at least one groove which extends from the same side of the metal web member as the teeth.

Abstract: The present invention relates to a three dimensional metal framework, designed for forming isothermic walls of buildings, which comprise an inner air cavity in form of a blade along one of its faces.This framework (9) comprises rectilinear and parallel rods (14) which are welded, in at least two parallel rows (14a, 14b), on sinusoidal wires (15) which extend in planes perpendicular to the rectilinear rods and whose tops (15a, 15b) are situated in two planes parallel with the two rows of rectilinear rods, the first row (14a) of rectilinear rods being furthermore slightly spaced apart from a first one of the planes containing the tops (15a) of the sinusoidal wires.The invention also relates to a constructional element built from this framework and comprising a bearing wall (4) and a heat insulating layer (5) both disposed between the two rows (14a, 14b) of the rectilinear rods of the framework (9) as well as two finishing coverings (2b, 3b) formed on the tops (15a, 15b) of the sinusoidal wires of the latter.

Abstract: A plurality of V-shaped metal web members serve to interconnect two elongated wooden members for forming a truss or joist assembly. The two elongated wooden members are arranged so as to extend parallel to each other with a spacing therebetween. The metal web members are placed in the spacing between the wooden members and have their extremities connected to the wooden members. Each of the metal web members has connector nail plates located both at its apex and at each of its extremities. Struck out from each connector plate are a plurality of pairs of teeth with each pair of teeth leaving a corresponding slot between them. All of the teeth extend from the same face of the metal web member. Each of the connector plates at the two extremities is connected to the apex connector plate by a leg member. Each of the legs has at least one groove which extends from the same side of the metal web member as the teeth.

Abstract: The invention relates to a support system for buildings having straight, longitudinally and transversely extending girders which are subjected to both compressive and tensional stresses. The girders are releasably connected to one another by connecting members. The girders and the connecting members are each in the form of a single casting made of a ductile metallic material such as gray cast iron with spheroidal graphite, malleable cast iron or cast steel.

Abstract: A composite floor system includes a plurality of joists, each having a top and bottom chord and a web in the space between the chords. The top chord includes a pair of angle bars, each having a vertical leg of differing heights and a horizontal leg. The top of the web extends between the vertical legs of the chord to a point between or level with the top of the larger vertical leg of the angle bars. Decking is supported by the horizontal legs of the top chord of adjacent joists and a concrete slab poured on the decking and between the vertical legs of the top chord to provide bonding between the concrete slab, top chord and web.

Abstract: A girder defined by spaced apart, parallel upper and lower longitudinally corrugated chord plates and an intermediate, sinusoidal connecting member defining serially arranged, diagonally disposed webs and web connecting upper and lower crown sections in contact with the chord plates. Means is provided to assure metal-to-metal contact between the connecting member and the chord plates. The crown sections of the former are secured to the chord plates at their common contact points. The connecting member has corrugations complementary to those of the chord plates.

Abstract: A floor is disclosed comprising joists partially embedded in a slab. The joists are composed of a web and two flanges, the web having a lattice structure and the slab consisting of a cast, light material.

Abstract: A roof supporting structure and method of erecting such structure, the structure comprising a series of spaced apart rafters lying in parallel relation with a series of V-truss units extending between the rafters in parallel relation at spaced apart intervals to define rows of V-truss units supported at their opposite ends on the rafters, the V-truss units in a given row lying in alternating relation with respect to the V-truss units in the next adjacent row, the ends of the V-truss units in one row being interconnected with the adjoining ends of the V-truss units in the next adjacent row so that horizontal forces will be transmitted jointly by the V-truss units in adjacent rows. Modified V-truss units may be provided at the ends of alternate rows to further enhance the horizontal load supporting capability of the structure, the modified V-truss units additionally serving to mount the wall panels of a building utilizing the roof supporting structure.

Abstract: A truss made for use in the manufacturing of reinforced concrete slabs including a web portion so formed that it provides a series of V-shaped risers joined together by a center segment which lie along a common axis, with each alternate riser inclined downwardly and outwardly to opposite sides of the center segment. The V-shaped risers will have connected thereto horizontally disposed bottom chords and a top chord that extends through each of the center segments connecting the V-shaped risers together thus forming a reinforced truss.

Abstract: The present invention relates to a truss of the lattice type. The truss comprises an upper and lower chord of wood and a continuous web of steel in a zig zag configuration arranged between the chords to form inclined struts. The bent portions of the web are received in recesses in the chords and fastened in the recesses by a hardening and binding substance which forms a body which replaces wood removed to form the recesses.

Abstract: A modular light-weight structural panel is made by stacking in consecutive alternation a number of long, narrow foam plastic filler elements with a number of substantially flat lattice structures. The sub-assembly is laterally compressed to cause each of the lattice structures to be pressed into and partially embedded in mutually abutting surfaces of adjacent ones of the filler elements. While in such compressed condition cross members are welded to side portions of the lattice structures that protrude beyond the filler element surfaces to thereby hold the assembly in its pressed condition with the lattice structures embedded in the filler elements and surfaces of adjacent filler elements in close face-to-face contact with one another.

Abstract: The frame girder for underground drift construction comprises three or more retainer bars (3a, 3b) whose cross sections form a polygon, the retainer bars being affixed to one another by stiffener elements (4). Each stiffener element (4) comprises a number of cross struts (5) bent in their centers and inclined with respect to the retainer bars. The outer ends (9) of the struts (5) are each attached to one of the retainer bars. The stiffener element may be formed symmetrically with respect to a central plane extending obliquely to the retainer bars. The frame girder may be made from conventional round irons. It resists bending, torsion and buckling at very high loads, and no undesirable injection shadows are produced during concreting.

Abstract: A sheet metal web unit for interconnecting vertically spaced apart, horizontal wood chords, is formed as an elongated channel-shaped strut with integral, flat, connector plates on its upper and lower ends. The channel is curved and shallower at the lower end of the strut and gradually gets deeper and flatter towards the upper end. The width of the channel gradually decreases and the depth of the channel legs gradually increases from the lower end to the upper end of the strut. A W-shaped web unit is formed of four of such struts integrally connected together by common connector plates. The connector plates overlap vertical face portions of the wood chords and have struck-out teeth for embedding within those overlapped face portions. The ends of the channel leg portions which are closest to the connector plate teeth are extended to overlap and also embed into the adjacent chord face portion to thereby reduce the load on the tooth nearest to the respective strut end.

Abstract: A building construction comprising a plurality of panels. Each panel comprises spaced sheets and a plurality of spaced longitudinally extending truss members. Each truss member comprises a pair of channels and an undulating member comprising alternating first and second apices connected by legs, the apices being bonded to the channels. At least one of the sheets has longitudinally extending grooves receiving the truss members. The grooves have a cross sectional configuration conforming to the cross sectional configuration of the channel of the truss member. The channels are fastened to the sheet. The panels may be used in the side wall or roof of a building.

Abstract: A girder or like structural element of the kind consisting of a pair of chords, which are usually parallel, and a web in the form of a zigzag strip consisting of oblique straights alternating with crests by which the web is joined to and between the chords by welding or otherwise, is characterized in that each of the crests is a flat of parallelogrammatic form and has the larger of the supplementary angles of the parallelogram at between 120.degree. and 150.degree.; and, each of the straights has its major cross-sectional dimension extending in a plane parallel to that of the chords or at least having a component parallel to the plane of the chords.

Abstract: A metal truss structure which is characterized by chord and web members formed of rectangular tubing and with the chords of double construction to take advantage of the weight and cost savings and high torsional strength of rectangular tubing and arranged for easy and inexpensive fabrication by avoiding precise cutting and difficult welding requirement. This metal truss structure comprises chords, each including a pair of laterally spaced-apart rectangular tubing members positioned flat against opposite sides of the rectangular tubing web members at one corresponding end and welded exclusively by weld lines extending along the longitudinal intersections of the chord members with the web members for simple and automatic welding.

Abstract: A beam formed of an assembly of a pair of vertically spaced apart wood chord members interconnected by a number of angularly arranged, channel shaped struts located along the vertical faces of the chords and on opposite sides of the chords. The channel base of each strut is V-shaped in cross-section, with an apex angle that increases from top to bottom of the strut so that the base gradually flattens along the strut length in the upwards direction. The channel legs of each strut gradually increase in depth from bottom to top along the strut length, to thereby shift the location of the channel's neutral axis away from the base towards the free edges of the legs at the upper end of the strut. The upper and lower ends of the struts are extended to form enlarged, flat, connector plate portions having struck-out teeth for embedding into the adjacent vertical face portions of the chord members.

Abstract: A beam having flanges composed of wood pieces and a web consisting of a wire member bent alternately back and forth to extend between and being attached to the flanges at the bends. Each flange comprises at least two wood pieces which extend longitudinally of the beam and are joined together by gluing, at least one of the wood pieces having recesses in the surface joined with the other wood piece, which recesses are adapted to receive the bends of the wire member. The beam is manufactured in that recesses are arranged at regular intervals in a long wood piece, whereupon two such wood pieces provided with recesses are placed at a distance from one another corresponding to the distance between the flanges of the beam to be made, with the recesses in one wood piece exactly opposite to points situated halfway between the recesses in the other wood piece.

Abstract: Adjustable shoring apparatus includes upper and lower pairs of horizontally extending spaced apart parallel chords, a plurality of struts extending obliquely from the upper chord pair to the lower chord pair and between the chords in each pair in a continuous longitudinal series of strut pairs of like substantially V-shaped configuration having their apices at the lower chord pair, means connecting the upper and lower ends of the struts respectively to the chords of the upper and lower pairs in a truss-like structure adapted for supporting a load on the chords of the upper pair, a plurality of vertically extending elongated legs each having a vertical series of support pin holes which extend transversely therethrough, the legs having upper portions inserted between the chords in the lower pair and lower portions extending below the structure to provide support therefor, the legs being vertically reciprocally movable relative to the structure for adjusting the combined height thereof, the strut pairs in said s

Abstract: A truss joist includes an upper chord, a lower chord and a series of links. The series of links connects the upper and lower chord and terminates in an end link which is attached to the lower chord and extends upwardly toward the terminal portion of the upper chord. An end bracket which partially surrounds the terminal portion of the upper chord includes a U-shaped channel which contacts the side and bottom surfaces of the upper chord. The U-shaped channel further comprises a pair of downwardly projecting legs for connectively receiving the flattened end portion of the end link. One embodiment of the end bracket lies directly upon the upper surface of a support member. Another embodiment is flush-mounted against the inner surface of the support member and has a horizontal flange which extends over the upper surface of the support member. Additional embodiments of the end bracket include adjustable bracket elements mounted below the U-shaped channel and on either side of the downwardly projecting legs.

Abstract: A composite action open-web steel joist, supporting beams and girders, and reinforced concrete slab interconnection. Upper apex portions of the steel joist webbing protrude through the upper chord members of the joist, and through apertures provided in the sheet metal formwork placed over such joists prior to the pouring of the concrete slab.

Abstract: A metal beam system for metal-concrete structure comprises one or two sinusoidal steel wires welded to a plate along one edge of the sinusoid and welded to two round steel bar stringers along the other edge. The round steel bar stringers are along the upper part of the sinusoid for principal and floor beams and along the lower part for the perimetrical beams.

Abstract: A building construction comprising a foundation, a plurality of vertically extending truss members and a plurality of roof frames. Each truss member comprises spaced channels with alternately extending struts connected between the channels. Each roof frame is associated with opposed pairs of the upright truss members and includes vertical legs comprising truss members aligned with the upright truss members and horizontal truss members of substantially identical construction extending between the upright legs.

Abstract: The frame girder for underground drift construction comprises three or more retainer bars (3a, 3b) whose cross sections form a polygon, the retainer bars being affixed to one another by stiffener elements (4). Each stiffener element (4) comprises a number of cross struts (5) bent in their centers and inclined with respect to the retainer bars. The outer ends (9) of the struts (5) are each attached to one of the retainer bars. The stiffener element may be formed symmetrically with respect to a central plane extending obliquely to the retainer bars. The frame girder may be made from conventional round irons. It resists bending, torsion and buckling at very high loads, and no undesirable injection shadows are produced during concreting.