Title of Invention

A MODULAR LOAD-CARRYING STRUCTURE

Abstract

The invention relates to a modular load-carrying structure comprising vertical support posts (1) interconnected by long-span horizontal beams (2, 10), some of which bear on sloping bracing struts (12). In accordance with the invention, each beam (10) which bears on sloping bracing struts (12) is constituted by two juxtaposed glued-laminated webs defining a central space in which a passive cable (20) passes freely, which cable is secured at its two ends to corresponding posts (1), the beam resting on the sloping bracing struts (12) via end plates (21) arranged between the two juxtaposed webs and rigidly secured thereto. Figure 1.

Full Text

A MODULAR LOAD-CARRYING STRUCTURE FIELD OF THE INVENTION The present invention relates to a load-carrying structure including long-span horizontal beams. More particularly, the invention provides a modular load-carrying structure of the type comprising a plurality of vertical support posts connected to one another by long-span horizontal beams, at least some of the beams bearing in the vicinity of their ends on sloping bracing struts whose bottom ends are hinged to the corresponding posts. BACKGROUND OF THE INVENTION Document FR—A—2 611 781 describes the principle of such a load-carrying structure with a bearing and fastening system for long-span beams arranged so that the ends of the beams bear on sloping bracing struts whose bottom ends are hinged to the vertical posts. The ability to use such long-span beams constitutes a major advantage when making floors or ceilings of large mesh size, particularly when building shops or warehouses of large area. In that bearing and fastening system for long-span beams on metal support posts, where the beams are preferably made of glued-laminated wood or of composite material, said system is arranged in such a manner as to enable the vertical reaction to the weight of the beam to be transferred as a bracing force into the corresponding posts, thereby establishing a horizontal force in the beam putting it under longitudinal stress which has the result of increasing the span that is possible for such a beam. The theory taught in that document nevertheless appears to be difficult to implement in practice, but it is still useful as a scientific reference from which more concrete embodiments can be derived. The technological background of the invention is also illustrated by Document BE—A 516 495. That document describes another arrangement of a metal beam bearing on hinged struts. OBJECT OF THE INVENTION The present invention seeks to devise a modular load-carrying structure that likewise includes beams whose ends bear on sloping bracing struts whose bottom ends are hinged to vertical posts, but of a design that provides good performance and is inexpensive to make. The invention also seeks to devise a modular load-carrying structure having long-span horizontal beams of glued-laminated wood which is easy and quick to put into place while enabling modular structures to be made with large mesh size, in particular a size of at least 800 square meters (m2) to 900 m2. BRIEF DESCRIPTION OF THE INVENTION In accordance with the invention, this problem is solved by Sa modular load-carrying structure comprising a plurality of vertical support posts interconnected by long-span horizontal beams, at least some of the beams bearing in the vicinity of their ends on sloping bracing struts which are hinged at their bottom ends to the corresponding posts, the structure being remarkable in that each long-span horizontal beam which bears on sloping bracing struts is constituted by two juxtaposed glued-laminated webs interconnected by spacers, said spacers defining a central space in which there passes freely a passive cable which is attached at its two ends to the corresponding posts, the beam bearing on said sloping bracing struts via respective end plates arranged between the j uxtaposed webs and rigidly secured thereto. Thus, unlike the long-span glued-laminated beams mentioned in above-cited document FR—A—2 611 781, the present invention has genuine box-beams with the central space thereof being used to advantage, in particular for passing the passive cable and at least a fraction of the end plates which are disposed between the juxtaposed webs. It is clear that such a design is not suggested in any way by the teaching of that document. Preferably, the spacers interconnecting the two juxtaposed webs of a long-span horizontal beam are made in the form of a high filler and a low filler each extending in the longitudinal direction of said beam. In particular, the high and low fillers are made of wood, and are connected to the adjacent webs by glue. Also advantageously, the passive cable arranged between the two juxtaposed webs of a long-span horizontal beam presents an enlarged head at each of its two ends, the enlarged head being received in an end-fitting box formed at the head-end of the post or bearing against a plate fixed to the head-end of the post. In practice, if concrete posts are used, then it is preferable to use end-fixing boxes which are bedded in the head-end of the post, whereas if metal posts are used, then plates are used that are fixed to the posts for the purpose of having the enlarged heads of the passive cable bearing thereagainst. Also preferably, the passive cable arranged between the two juxtaposed webs of a long-span horizontal beam passes beneath transverse pins interconnecting said webs, said pins being positioned on a predetermined installation curve so as to form bearing points for the cable when said cable is tensioned. Advantageously, the two juxtaposed webs are terminated by end facets which are directly in the vicinity of the corresponding posts, said posts being preferably fitted with safety angle bars to prevent twisting. It is also advantageous to provide for the end plates arranged between the two juxtaposed webs for bearing on the corresponding sloping bracing struts to be secured to said webs by through bolts. In particular, the end plates are made of steel, and are terminated adjacent to the corresponding struts by a pair of bearing facets, one of which is horizontal and the other vertical. In which case, advantageously, each sloping bracing strut presents a two-lobe head at its top end comprising a bottom lobe for transmitting a vertical bearing force and a top lobe for transmitting a horizontal bearing force. Each sloping bracing strut may present a narrower section in the vicinity of its two-lobe head so that said head can pass between the juxtaposed webs, the bearing zone then being located in the central space defined by said webs, Also preferably, each sloping bracing strut presents a cylindrical toe which is received in an associated fitting fixed to the corresponding post, said fitting presenting a cylindrical cradle of horizontal axis for this purpose. Also advantageously, each sloping bracing strut is made of steel in the form of a flat element extending in a vertical plane. Provision can be made for each sloping bracing strut to be coated in an anti-corrosion and/or anti-fire material. In another particular embodiment, the two juxtaposed webs of a long-span horizontal beam present an intrados surface which is curved, so that said beam presents a camber c. which is at a maximum halfway along the beam. In particular, the maximum camber c is given by the relationship: c = 0.013 X ^L where L is the length of the long-span beam. BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the invention appear more clearly in the light of the following description and the accompanying drawings showing particular embodiments with reference to the figures in which: • Figure 1 is a perspective view of a portion of modular load-carrying structure in accordance with the invention, in which there can be seen five long-span horizontal beams bearing on sloping bracing struts, with the other horizontal beams in this case being of traditional type; • Figure 2 is a perspective view on a larger scale showing the head zone of one of the vertical posts which in this case is made of concrete shown in the above load-carrying structure (the ends of the horizontal beams are shown as being "transparent" for greater clarity); • Figure 3 is a perspective view of the end of two beams bearing on sloping bracing struts, the other elements of the load-carrying structure not being shown in order to keep the figure uncluttered; • Figure 4 is a view on a larger scale showing the head zone of a post, in order to show more clearly the end-fitting box bedded in said post; • Figure 5 is an elevation view of the zone associated with a post head, showing the ends of two long-span horizontal beams bearing on sloping bracing struts, the beam on the right in the figure being shown during mounting, as can be seen from the temporary positioning means shown which are implemented in this case in the form of a bracket fixed to the post; • Figure 6 is an elevation view in isolation partially cutaway at both ends of the beam showing the long-span beam which is made as a box-beam with its passive cable extending along the length of said beam; • Figures 7 and 8 are cross-sections on lines VII-VII and VIII-VIII of Figure 6 showing more clearly the structure of the box-beam, showing diagrammatically the glued-laminated structure of the juxtaposed webs forming said box-beam; • Figure 9 is a partially cutaway fragmentary perspective view on a larger scale showing the front web forming the box-beam, and end plate of said box-beam bearing on the two-lobe head of a sloping bracing strut; ■ Figure 10 is a view analogous to Figure 6 showing a variant in which the long-span beam has a curved intrados to form a camber; and • Figure 11 is a cross-section on line XI-XI of Figure 10. DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a modular load-carrying structure or superstructure S which is arranged in this example to form the load-carrying framework of a building in the form of a rectangular parallelepiped of large dimensions, such as a warehouse or a superstore. The structure S comprises a plurality of vertical support posts 1 sunk in ground P via concrete foundations, which posts are connected to one another by long-span horizontal beams. Specifically, the figure shows posts 1 which are made of concrete, but naturally the invention need not be limited in this respect in any way, it would equally well be possible to use metal posts, for example of H-section (variant not shown). In addition, this figure shows vertical posts of considerable height, for example about 10 meters, so as to provide a load-carrying structure for a roof or a higher floor of a building. Nevertheless, it should be understood that the invention is equally applicable to a load-carrying structure associated with supporting a floor in a building of large area. The vertical support posts 1 are interconnected by long-span horizontal beams referenced 2, 10. The beams 10 which extend parallel to one another have their ends 11 bearing on sloping bracing struts 12 which are hinged at their bottom ends to the corresponding posts 1. In contrast, the long-span horizontal beams 2 which extend orthogonally to the direction in which the beams 10 extend are shown in this case as being of traditional type, i.e. they are set in fittings fixed at the tops of the beams. For one of the modules of the load-carrying structure S, the figure shows conventional type metal joists 5, frequently referred to as "Canam" joists in the art, these metal joists bridging pairs of long-span horizontal beams 10. Thus, a module or mesh of the load-carrying structure S is constituted in this case by four vertical support posts 1, two long-span horizontal beams 2 of traditional type, and two long-span horizontal beams 10 bearing on sloping bracing struts, with a series of metal joists 5 bridging the two above-mentioned beams 10. As an indication, the arrangement of the invention makes it possible to implement modular load-bearing structures of very large dimensions, a unit module possibly being 24 meters wide by 36 meters long, of height given by the height of the vertical posts 1 which may lie in the range 10 meters to 15 meters, for example. Bracing is provided firstly by the vertical posts 1 being sunk into concrete, and secondly by truss girders 5.1 interposed between pairs of Canam joists 5 (two such girders are shown in Figure 1) and two crossed cables 5.2 tensioned by turnbuckles 5.3. The long-span horizontal beams 2 and 10 are made of glued-laminated wood, but they are not made in the same way. Thus the transverse beams 2 are of traditional type, being constituted by a single glued-laminated block of rectangular section, with a depth of 1 meter to 1.2 meters and a width of about 0-2 meters. The ends of the beams 2 are set in metal bearing plates 40 which can be seen more clearly in Figure 2. These metal fittings 40 are of traditional type and they are screwed to the sides of the corresponding posts 1 at their top ends. In contrast, the long-span horizontal beams 10 which bear on sloping bracing struts 12 are of a box-beam type structure which is described in greater detail below with reference to Figures 2 to 9. As can be seen more clearly in Figures 6 to 8, the long-span horizontal beam 10 which bears on sloping bracing struts 12 is constituted by two juxtaposed glued-laminated webs 16.1 and 16.2 which are connected together by spacers defining a central space 19. Specifically, the spacers interconnecting the two juxtaposed webs 16,1 and 16,2 of the horizontal beam 10 are made in the form of a high filler 17 and a low filler 18, each extending in the longitudinal direction of the beam. The high and low fillers 17 and 18 are then preferably made of wood, and they are connected to the adjacent webs 16,1 and 16.2 by gluing. It can thus be seen that the structure in the form of two juxtaposed webs 16.1 and 16,2 connected together by high and low fillers does indeed constitute a wooden box-beam of depth that may commonly reach 1.40 meters and of width of the order of 0.45 meters for a beam having a span of 36 meters, A passive cable 20 passes freely in the central space 19 as defined in this way, the cable being secured at each of its two ends to the corresponding post 1. Since the long-span beam 10 may be of a length that easily reaches 3 6 meters, provision may be made for the passive cable 20 to be implemented not as a single segment, but as an assembly comprising a plurality of segments connected together end to end by couplers (not shown) made in the form of sleeves, as is conventional in the building industry, in particular for structures such as guyed bridges. The function of this passive cable 20 is described in greater detail below. The head ends of the posts 1 are arranged to be suitable for anchoring the ends of each passive cable 20, where such a cable presents a diameter of about 70 millimeters, for example. Specifically, and as can be seen more clearly in Figures 3 and 4, the passive cable 20 which is housed between two juxtaposed webs 16.1 and 16.2 presents an enlarged head 26 at each of its ends, which head extends beyond the end facets of said webs. Since the posts 1 are made of concrete in this case, an end-fitting box referenced 30 is provided in the head-end of the post. This end-fitting box 30 is thus set into the top of the post and comprises an H-section metal core 35 which extends vertically together with a hollow space 31 that is open to the top. The space 31 communicates with two side faces defined by slots 32 through which the ends of the cables 20 pass. A bearing wedge with a sloping face 33 is provided for the enlarged head 26 of each passive cable 20 to bear against, each bearing wedge 3 3 itself bearing against the walls of the end-fitting box 3 0 which are adjacent to the space defined by the slots 32. Although not shown herein, it would naturally be possible in a variant to provide vertical posts that are made of metal, in which case the enlarged heads 26 of the passive cables 20 could be anchored by bearing plates fixed at the head ends of the posts. As can be seen in Figures 5, 6, and 8, the passive cable 20 arranged between two juxtaposed webs 16.1 and 16.2 of a long-span horizontal beam 10 passes beneath transverse pins 25 interconnecting said webs. These pins 25 are positioned longitudinally on a predetermined installation curve so as to form bearing points for the cable 20 when the cable becomes tensioned. The predetermined installation curve can then be implemented substantially as an arc of a circle or as an arc of a catenary. As can be seen in Figure 8, each of these pins is implemented in the form of a bolt passing through the two juxtaposed webs 16.1 and 16.2, and held by means of a threaded nut engaged on its free end. As can be seen more clearly in Figure 4, the two juxtaposed webs 16.1 and 16.2 are terminated by respective essentially vertical end facets 27.1 and 27.2 which are directly in the vicinity of the corresponding posts 1. In practice, a small amount of operating clearance is provided, for example of the order of a few centimeters, insofar as it would naturally be undesirable for end thrust to be applied to the long-span horizontal beams since this would cause the beam to be statically undetermined. Specifically, safety angle bars 34.1 and 34.2 are screwed to the vertical support posts 1 with each angle bar extending vertically beside the side facets of the juxtaposed webs 16.1, 16.2. These angle bars are safety elements against twisting, i.e. they serve to prevent any twisting movement of the box-beam about its passive cable. As mentioned above, the box-beam 10 bears against the sloping bracing struts 12 via end plates 21 which are arranged between the juxtaposed webs 16.1 and 16.2, and which are rigidly secured thereto. These end plates 21 are thus arranged between the two juxtaposed webs 16.1 and 16.2 for bearing on the sloping bracing struts concerned 12, and they are secured to said webs by through bolts 24. Specifically, the end plates 21 or distribution plates are fully integrated in the central space 19 of the box-beam. These end plates 21 are preferably made of steel, and adjacent to the corresponding struts 12 they terminate in two bearing facets, one of which is horizontal and the other vertical. The end referenced 22 of the end plate 21 which is concerned by bearing on the sloping strut 12 can be seen more clearly in the large-scale view of Figure 9. This view shows clearly the bearing facets 22.1, 22.2 which are mutually orthogonal, the facet 22.1 being essentially horizontal and the facet 22,2 being essentially vertical. This figure also shows the set of through bolts .24, there being twenty-one such bolts in this example. The other end of the end plate 21 is referenced 23 and presents a top setback for passing the passive cable 20, It should be observed that the end plate 21 extends in a direction which corresponds substantially to the slope of the sloping bracing strut 12, which slope is at abut 20° relative to the horizontal, for example. Figure 9 also shows that the sloping bracing strut 12 presents a two-lobe head 15 at its top end, comprising a bottom lobe 15.1 for transmitting a vertical bearing force and a top lobe 15.2 for transmitting a horizontal bearing force, these two lobes being spaced apart by a deeper notch 15.3 seeking to avoid any contact taking place against the end edge of the plate 21, It should be observed that in this case the sloping bracing strut 12 has a narrowing in its width in the vicinity of the two-lobe head 15 so that said head can pass between the juxtaposed webs 16.1, 16,2 forming the box-beam 10. This enables the two-lobe head 15 to penetrate into the central space 19 of the box-beam so that the bearing zone on the sloping strut 12 is completely protected. Specifically, it can be seen that the bottom lobe 15.1 is shaped so as to come into substantially point contact with the horizontal facet 22,1 of the plate 21, while the top lobe 15,2 is shaped so as to transmit a horizontal bearing force over an area between the vertical facet 22.2 and said end plate 21. Each sloping bracing strut 12 is preferably made of steel, in the form of a flat element extending in a vertical plane, As can be seen more clearly in Figure 5, each sloping bracing strut 12 presents at its bottom end a cylindrical toe 13 which is received in an associated fitting 14 fixed to the corresponding post 1, For this purpose, the fitting 14 presents a cylindrical cradle 14.1 having a horizontal axis. This enables the strut 12 to be hinged about a horizontal axis secured to the vertical support posts 1, As a subsidiary matter, the fitting 14 presents an outside facet 14,1 that slopes, which facet does not make contact with the adj acent facets at the end of the sloping strut 12 so as to allow said strut to move angularly to a certain extent about its bottom horizontal axis. Provision could also be made for the sloping bracing struts 12 to be coated in an anti-corrosion material and/or an anti-fire material for best protection. Figure 5 also shows, in its right-hand half, temporary means for providing assistance during assembly. There can be seen a temporary bearing structure 100 made in the form of a metal bracket. The bracket 100 comprises a horizontal beam 101 fixed to the post 1 by a plate 102, the direction of said beam which extends in a vertical plane being controlled by a Y-shaped top assembly 107, Two vertical links 103 and 104 have their free bottom ends fixed to the strut 12 at points 105 and 106 which are accurately determined so as to define a determined angle relative to the horizontal, e.g. 20°. The metal bracket 100 is thus put into position on the vertical post 1 against the sloping strut 12 while it is being put into place. Under such circumstances, it suffices to fix the strut 12 via its points 105 and 106 to ensure that its slope is quite correct. The end of the box-beam 10 is then put into place so as to bear against the two-lobe head 15 of the sloping strut 12, Such a metal bracket 100 thus makes installation of the box-beams quick, simple, and completely safe. The brackets are preferably left in place until the set of metal joists bridging the box-beams have been finally secured. Thus, the metal junction elements installed inside the box-beam during manufacture thereof are constituted by the passive steel cable 20 and by the two end plates 21. Because of the small amount of vertical deformation to which the posts are subject under loading, and because of the sagging of the box-beam on its support, the passive cable 20 is progressively tensioned, thus pulling the box-beam upwards. This tension exerted on the passive cable 20 has the effect of lifting said cable by tensioning it until it comes into contact with the transverse bearing pins 25. The two end plates 21 which are also made of steel serve to receive the heads of the struts 12 and to transmit the compression forces to all of the fibers constituting the wooden laminations making up the glued-laminated structure. The transverse beams 2 which are also glued-laminated have the effect of side bracing each module of the load-carrying structure and of providing continuity between assemblies. Naturally, in a variant, it would be possible, instead of using traditional glued-laminated beams, to use box-beams analogous to the beams 10, but that would lead to a superstructure that is much more expensive. The Canam type metal joists 5 occupy amounts of space that vary from a maximum at a ridge to a minimum at their ends so as to provide a slope for directing rain water towards the box-beams which are themselves lightly sloped away from a central ridge, as is conventional in this field. Each metal joist 5 is then fixed at its head-end to one of the webs of the box-beam by means of a suitable end bolt. The spacing between the joist 5 varies as a function of the thickness of the roofing strip material that is to be used. Thus, the arrangement of the load-carrying structure of the invention is characterized by the notion of making use of forces at the ends of horizontal beams that are fixed to posts, not by being set therein, nor via passive hinges, but via active hinges which transmit in compression into the beams the loads and excess loads that are applied in the horizontal plane created thereby. with this being done by using elements made of metal. Thus, instead of combating weight, weight is used to reinforce the energy that is usually spent in deforming sockets for receiving the ends of the beams in the posts, with this continuing until final equilibrium is obtained for the horizontal element. This potential energy of the weight forces is thus not used to deform the end fittings or to bend the beams, but is used in compression via the hinged struts arranged at each end of the beams, and via the passive cable integrated in each box-beam and fixed to the top end of the post. The economic performance of such an arrangement lies, amongst other things, in the balance between dimensioning in the horizontal plane and dimensioning in the vertical plane, it being understood that under all circumstances ground reaction remains an important parameter in the overall cost of a superstructure. In order to put each box-beam into place, holes are initially made in a web laid flat, and then the fillers and the two end plates are put into position, by being glued onto the top face of the web. A second web is then put into place, after which the resulting assembly is set upright in order to position the various pins, both the pins associated with bearing against the passive cable, and the bolts for fixing the end plates. All of these bolts are naturally tightened using a torque wrench so as to avoid undesirable splitting of the wood. It is important to observe that all of the critical elements of the structure are well protected: this applies to the passive cable, to the end plates with their bearing zones on the strut heads, and also to the sloping bracing struts insofar as they are coated in a layer of anti-corrosion and/or anti-fire varnish. In all of the embodiments described above, the bottom surface or intrados of two juxtaposed webs of a long-span beam is essentially plane, i.e. the profile of the beam is rectilinear. Nevertheless, in a variant, it is possible to make provision for the two juxtaposed webs to present a curved intrados surface so as to form a camber or "hog's back". Such a variant is shown in Figures 10 and 11. These figures use the same references as are used in Figures 6 and 7. It can be seen that the intrados surface, referenced 28, is curved so that the load-span beam 10 presents a camber (c) which is at a maximum halfway along the beam. In particular, provision can be made for the maximum camber (c) to be given by the relationship: c = 0.013 X ^L where L is the length of the beam 10. This then corresponds to a camber of 1.3%. In the special case of a beam that is 36 meters long, this maximum value of the camber is 0 . 234 meters. The presence of such a camber makes it possible to obtain better control over the forces due to bending moments, and also encourages water to flow off a roof because of the slope formed in this way, which guides rain water towards the end of the long-span beam. The above formula c = 0.013 x 5^L corresponds to optimizing the lever arm regardless of the length of the long-span beam resting on its hinged bearings. The invention is not limited to the embodiments described above, but on the contrary covers any variant using equivalent means to reproduce the essential characteristics specified above. CLAIMS 1. A modular load-carrying structure comprising a plurality of vertical support posts (1) interconnected by long-span horizontal beams {2, 10), at least some of the beams (10) bearing in the vicinity of their ends (11) on sloping bracing struts (12) which are hinged at their bottom ends to the corresponding posts (1), wherein each long-span horizontal beam (10) which bears on sloping bracing struts (12) is constituted by two juxtaposed glued-laminated webs (16.1, 16.2) interconnected by spacers (17, 18), said spacers defining a central space (19) in which there passes freely a passive cable (20) which is attached at its two ends to the corresponding posts (1), the beam bearing on said sloping bracing struts (12) via respective end plates (21) arranged between the juxtaposed webs (16.1, 16.2) and rigidly secured thereto. 2. A load-carrying structure according to claim 1, wherein the spacers interconnecting the two juxtaposed webs (16.1, 16.2) of a long-span horizontal beam (10) are made in the form of a high filler (17) and a low filler (18) each extending in the longitudinal direction of said beam. 3. A load-carrying structure according to claim 2, wherein the high and low fillers (17, 18) are made of wood, and are connected to the adjacent webs (16.1, 16.2) by glue. 4. A load-carrying structure according to claim 1, wherein the passive cable (20) arranged between the two juxtaposed webs (16.1, 16.2) of a long-span horizontal beam (10) presents an enlarged head (26) at each of its two ends, the enlarged head (26) being received in an end-fitting box (30) formed at the head-end of the post or bearing against a plate fixed to the head-end of the post. 5. A load-carrying structure according to claim 1, wherein the passive cable (20) arranged between the two juxtaposed webs (16.1, 16.2) of a long-span horizontal beam (10) passes beneath transverse pins (25) interconnecting said webs, said pins (25) being positioned on a predetermined installation curve so as to form bearing points for the cable (20) when said cable is tensioned. 6. A load-carrying structure according to claim 1, wherein the two juxtaposed webs (16.1, 16.2) are terminated by end facets (27.1, 27.2) which are directly in the vicinity of the corresponding posts (1), said posts being preferably fitted with safety angle bars (34.1, 34.2) to prevent twisting. 7. A load-carrying structure according to claim 1, wherein the end plates (21) arranged between the two juxtaposed webs (16.1, 16.2) for bearing on the corresponding sloping bracing struts (12) are secured to said webs by through bolts (24). 8. A load-carrying structure according to claim 7, wherein the end plates (21) are made of steel, and are terminated adjacent to the corresponding struts (12) by a pair of bearing facets (22.1, 22.2), one of which is horizontal and the other vertical. 9. A load-carrying structure according to claim 8, wherein each sloping bracing strut (12) presents a two-lobe head (15) at its top end comprising a bottom lobe (15.1) for transmitting a vertical bearing force and a top lobe (15.2) for transmitting a horizontal bearing force. 10. A load-carrying structure according to claim 9, wherein each sloping bracing strut (12) is of narrower section in the vicinity of its two-lobe head (15) so that said head can pass between the juxtaposed webs (16.1, 16.2), the bearing zone then being located in the central space (19) defined by said webs. 11. A load-carrying structure according to claim 9, wherein each sloping bracing strut (12) presents a cylindrical toe (13) which is received in an associated fitting (14) fixed to the corresponding post (1), said fitting presenting a cylindrical cradle (14.1) of horizontal axis for this purpose. 12. A load-carrying structure according to claim 9, wherein each sloping bracing strut (12) is made of steel in the form of a flat element extending in a vertical plane. 13. A load-carrying structure according to claim 9, wherein each sloping bracing strut (12) is coated in an anti-corrosion and/or anti-fire material. 14. A load-carrying structure according to claim 1, wherein the two juxtaposed webs (16.1, 16.2) of a long-span horizontal beam (10) present an intrados surface (28) which is curved, so that said beam presents a camber c which is at a maximum halfway along the beam. 15. A load-carrying structure according to claim 14, wherein the maximum camber c is given by the relationship: c = 0.013 X HL where L is the length of the long-span beam (10). 16. A load-carrying structure substantially as herein described with reference to the accompanying drawings.

Documents:

902-che-2003-abstract.pdf

902-che-2003-assignment.pdf

902-che-2003-claims duplicate.pdf

902-che-2003-claims original.pdf

902-che-2003-correspondence others.pdf

902-che-2003-correspondence po.pdf

902-che-2003-description complete duplicate.pdf

902-che-2003-description complete original.pdf

902-che-2003-drawings.pdf

902-che-2003-form 1.pdf

902-che-2003-form 26.pdf

902-che-2003-form 3.pdf

902-che-2003-form 5.pdf

902-che-2003-other documents.pdf