EP0637647B1 - Element for the construction of composite elongated box beam like structures, method for using the element and elongated structure manufactured by this method - Google Patents

Abstract

The metal girder element (5, 6) comprises a web section (7, 10) fixed along its longitudinal edges respectively to an upper base section (8) and a lower base section (9). Each base section (8, 9) of this element (1, 2) comprises, on its outer surface which is opposite the web (7, 10), connection elements (12, 13), the number, dimensions and positions of which are predetermined so that the said connection elements (12, 13) are capable of withstanding the thrust (drive) forces on the said base section (8, 9) by concrete during the deformations intended for the structure thus formed. <IMAGE>

Description

The present invention relates to a structural element for producing, by successive structural elements, an elongated mixed structure of cross section of the box type comprising an upper and a lower concrete slab connected to each other over their entire length. by at least two metal beams.

The present invention also relates to a method for implementing the above-mentioned structural element in order to construct a mixed elongated structure of cross section of the box type by successive structural elements assembled one after the other, as well as an elongated mixed structure produced by the implementation of this method.

Numerous examples of metal beam elements, processes and mixed elongated structures of the aforementioned types are known.

In the present invention, there will be described mixed elongated structures constituted by beams of road or rail bridges, extending essentially in a main direction. It is understood that the present invention also applies to elongated mixed structures extending in two perpendicular main directions, for example to slabs comprising several beams of the aforementioned type juxtaposed, or to two parallel slabs connected one to the another by several parallel metal beams.

We thus know of bridge beams of mixed structure of the box type comprising two concrete slabs connected by metal beams, the core of which consists of flat sheets fixed end to end.

Also known from EP-A-0 283 383 is a box-type bridge beam comprising two slabs joined by two metal beams, the core of which is made up of pleated sheets fixed end to end.

For these two types of structure, the flanges and the webs of the beam elements are respectively connected to each other, for example by welding before pouring the concrete of the slabs or corresponding slabs, and the operations of assembling the metal beams and the operations of making and assembling the concrete slabs are carried out one after the other. The pace of work of the teams specialized respectively in welding work and in concrete work is therefore irregular, and the construction time of the structure concerned is long.

The object of the present invention is to remedy the drawbacks of metal beam elements, known methods and mixed elongated structures, and to propose a metal beam element and a new method of the aforementioned types making it possible to reduce the cost and the duration of realization of 'A mixed elongated structure as well as a mixed elongated structure produced by the implementation of this method.

According to the invention, the structural element of the aforementioned type is characterized in that it comprises at least two metal beam elements, a section of upper slab and a section of lower slab, in that each metal beam element comprises a section of core, fixed along its longitudinal edges respectively to an upper sole section and to a lower sole section, the upper and lower sole sections being fixed respectively to the upper slab section and to the lower slab section and in that that each sole section of said metal beam element comprises, on its external surface opposite to the core section, connection elements suitable for being embedded in concrete and connecting the sole sections to the concrete of the corresponding slab, the number, the dimensions and the positions of said connection elements of a sole section being predetermined so that said elements are capable of withstanding the driving forces of said sole section by the concrete of the corresponding section of slabs of the same structural element, during the deformations planned for said structure.

This new structure is to be compared with the known conventional structure in which each sole is continuous from one end to the other of the structure and is connected to the concrete slab corresponding essentially to its ends by connection elements. Significant efforts are therefore transmitted by the slabs to the sole and vice versa, so that the sole must be dimensioned to support all of these efforts, and must have an adequate thickness often equal to several centimeters: such a thickness poses in in addition to serious problems of joining sheets end to end, for example by welding.

On the contrary, according to the invention, the forces transmitted by the section of slabs to the section of sole are those generated at of this one stretch. They are therefore limited and require only a limited number of connection elements. Likewise, the thickness of the sole section can be reduced since the sole section only supports limited forces. Finally, the drive forces of the sole being fully supported at the level of the corresponding elongated structural element, two elongated and adjacent structural elements can be used and connected to each other without having to connect the corresponding sole sections.

According to a preferred version of the invention, the length of each of the sole sections is substantially less than the corresponding length of said metal beam element.

According to a second aspect of the invention, the method of the aforementioned type, in which the sections of slabs are connected to one another, on the other hand the sections of webs of said structural elements, is characterized in that that the sole sections are left separate from each other, and that we use to connect to each other the sections of slabs of predetermined connecting means adapted to transmit from a structural element to a structural element adjacent all the longitudinal forces generated inside the elongated structure during its use.

This saves the time and cost required for welding the sole sections. This is particularly interesting when trying to limit the duration of a construction site as much as possible.

In addition, the longitudinal forces being transmitted from a structural element to an adjacent structural element at the level of the slabs, it thus becomes possible to carry out the operation of connecting the sections of core, for example by welding, independently of the operation of making and connecting the slabs, which allows another significant time saving: it is thus possible to weld the webs of a structural element after having made the slabs of this element and the assets connected to the slabs of the previous element, therefore in time mask during the preparation and the realization of the slabs of the following structural element.

According to a third aspect of the invention, the mixed elongated structure of the aforementioned type is characterized in that it is produced by implementing the method according to the invention.

Other features and advantages of the invention will appear in the detailed description below.

• la figure 1 est une vue en perspective avec arrachement d'un élément de structure mixte de section transversale du type en caisson conforme à un mode de réalisation de l'invention;
• la figure 2 est une vue en élévation partiellement en coupe de l'élément de structure de la figure 1, montrant un élément de poutre métallique et les deux tronçons de hourdis correspondants;
• la figure 3 est une vue agrandie d'un détail de la figure 2;
• la figure 4 est une vue en coupe suivant IV-IV à la figure 3, représentant un mode d'assemblage de deux tronçons d'âmes;
• la figure 5 est une vue semblable à la figure 4 représentant une variante du mode d'assemblage de deux tronçons d'âmes;
• les figures 6 et 7 sont deux vues schématiques illustrant deux phases de la mise en place d'un nouvel élément de poutre métallique conforme à l'invention;
• la figure 8 est une vue agrandie du détail A à la figure 7;
• la figure 9 est une vue agrandie du détail B à la figure 7;
• la figure 10 est un schéma en élévation illustrant les moyens de liaison entre des éléments de structure mixte adjacents.

In the accompanying drawings, given solely by way of nonlimiting examples:

• Figure 1 is a perspective view with cutaway of a mixed structural element of cross section of the box type according to an embodiment of the invention;
• Figure 2 is an elevational view partially in section of the structural member of Figure 1, showing a metal beam member and the two sections of corresponding slabs;
• Figure 3 is an enlarged view of a detail of Figure 2;
• Figure 4 is a sectional view along IV-IV in Figure 3, showing a method of assembling two sections of souls;
• Figure 5 is a view similar to Figure 4 showing a variant of the method of assembling two sections of souls;
• Figures 6 and 7 are two schematic views illustrating two phases of the establishment of a new metal beam element according to the invention;
• Figure 8 is an enlarged view of detail A in Figure 7;
• Figure 9 is an enlarged view of detail B in Figure 7;
• FIG. 10 is a diagram in elevation illustrating the means of connection between adjacent elements of mixed structure.

In the embodiment shown in Figure 1, there are shown two adjoining elements 1, 2, of an elongated mixed structure of cross section of the box type: these elements are elements of a road or rail bridge beam.

We know that such a beam, which can be produced by assembling successive elements such as the elements of mixed structure 1 and 2, comprises an upper slab and a lower slab of concrete connected to each other over their whole length by at least two continuous metal beams. Each of the metal beams is constituted by a continuous core fixed along its longitudinal edges respectively to means forming an upper sole and to means forming a lower sole. Each sole has connection elements adapted to be embedded in the concrete to connect the concrete base of the corresponding slab.

Each structural element 1, 2, thus comprises a section of upper slabs 3 and a section of lower slabs 4, both made of concrete, connected in longitudinal direction by two elements of metal beam 5, 6.

The metal beam element 5, situated on the left of the figure, comprises a core section 7, which is a flat sheet, fixed along its longitudinal edges respectively to an upper sole section 8 and to a sole section lower 9.

The metal beam element 6, located on the right of the figure, comprises a core section 10 which is a pleated sheet, and two upper and lower flange sections which are for example identical to the flange sections 8 and 9 of the 'metal beam element 6, but can of course be different from these. This pleated sheet is for example of the type described in EP-A-0 283 383 in the name of the holder.

Conventionally, the upper slab section 3 extends beyond laterally at 3a beyond the metal beam elements 5, 6 to form the foundation of the roadway or of the railway track carried by the corresponding bridge.

In the left half-view, the concrete of the upper slab 3 has been poured and is shown.

In the right half-view, the concrete of this upper slab has not yet been poured, and the formwork prepared for receiving this concrete has been shown diagrammatically at 11 on either side of the corresponding upper flange section 8.

According to the invention, each sole section 8, 9 of the metal beam element 1, 2, has on its outer surface 8a, 9a, opposite the core 7, 10 of connection elements 12, 13, the number, dimensions and positions are predetermined so that said connection elements 12, 13 are capable of supporting the driving forces of said sole section 8, 9, by the concrete during the deformations provided for the beam bridge once it is completed and in service (or during resistance tests).

There is shown on the upper sole section 8 of element 1 of the connection elements 12 which are sections of angles welded to the outer surface 8a of this sole 8 along the edges of a wing of the angle.

There are shown on the sole 8 of the element 2 connection elements 13 which are head studs welded by their end opposite the head on the external surface 8a of the sole 8.

These connection elements 12, 13 are known in themselves and do not need to be described in detail here: they can be associated with each other and with any other type of known connection elements on the same section sole 8.

The same connection elements 12, 13 are fixed, for example by welding, to the external face of each section of lower sole 9.

In the embodiment shown in Figures 2 to 5, the length of each of the flange sections 8, 9 is substantially less than the corresponding length of the metal beam element 1, 2, which can be represented by the length of the section of concrete slabs 3, 4, adjacent.

Indeed, it is convenient to provide that the ends 14, 15 facing two sections of cores 7, 10, to be connected to one another overlap each other to allow a seam welding as shown in Figures 2 to 4, a weld bead 16 being formed along each edge of each core.

Another solution shown diagrammatically in FIG. 5 consists in welding an angle iron 17 along each end of the core 14, 15 and in joining the contiguous wings of two angles 17 with an adequate number of bolts 18.

In the embodiment of Figures 2 and 3, the upper sole section 8 does not cover the opposite face of the concrete slab 3 corresponding to the end of said slab. The corresponding end 14, 15 of the core 10, on the contrary, goes beyond the end of the slab 3 to cover the end 15, 14 of the adjacent core section. To facilitate the execution of the bridge beam elements and the connection of the webs of two adjacent elements, for example by welding on each side of the core, the end 14, 15 of the core can be connected to the sole 8 , 9 by a concave notch 19 which leaves the end of the the sole 8, 9.

All of the above applies equally to the lower sole sections 9 as to the upper sole sections 8 and to the pleated core sections 10 as to the flat core sections 7.

The bridge beam elements 1, 2 are commonly prestressed by cables stretched both in the longitudinal direction and in the transverse direction of the bridge beam (not shown). However, the present invention also applies to non-prestressed beams or structures.

Similarly, the bridge beam elements can be either prefabricated and assembled to one another in a known manner, or else assembled and produced on site, the concrete of the sections of slabs 3, 4 being poured on site, and this as well on the ground or on a support as in cantilever, in overhang.

In known manner, in the method for constructing a mixed elongated structure of cross section of the box type by successive structural elements assembled one after the other, the sections of slabs, on the other hand, the sections of cores of said structural elements.

According to the invention, the method of implementing the metal beam element described above for constructing such a mixed elongated structure is characterized in that the sole sections 8, 9 are separated from each other, and in that one uses to connect to each other the sections of slabs 3, 4 predetermined connecting means adapted to transmit from a structural element to an adjacent structural element all of the longitudinal forces generated at the inside of the elongated structure during use.

These connecting means are any known element: they can be passive elements such as concrete rods with a smooth surface or with high adhesion, or any other element known for this function.

These connecting means can also be active means such as cables stretched for prestressing the concrete, which can also be, and in a known manner, inserted into tubes embedded in the concrete and / or arranged outside the solid masses. concrete.

It is also possible to use both connecting means passive and active connecting means.

FIG. 10 shows the end of a mixed cantilever structure made up of three numbered structural elements (N-2), (N-1) and (N). The element (N) is fixed to the element (N-1) by tensioned prestressing cables shown diagrammatically at 35. Similarly, the element (N-1) is fixed to the element (N-2) by stretched prestressing cables shown diagrammatically at 36.

Passive connection means 37, 38 are also installed respectively between the element (N) and the element (N-1) and between the latter and the element (N-2).

All the longitudinal forces being transmitted to the slab sections 3, 4, it is unnecessary to weld or connect the flange sections 8, 9 to each other. It is also possible to offset the welding operations over time or assembly of the core sections 7, 10 of the operations for producing and assembling the sections of corresponding concrete slabs.

Thus, for the construction of a structure by assembling one after the other of prefabricated mixed structure elements, the upper and lower slab sections of an element (N) are first connected to the sections of upper 3 and lower 4 slabs of the preceding element (N-1), then the sections of cores 7, 10 of the element (N) are connected to those of the element (N-1).

• on coule le béton des hourdis inférieur 4 et supérieur 3 d'un élément (N):
• on relie les hourdis inférieur 4 et supérieur 3 de l'élément (N) respectivement aux hourdis correspondants de l'élément (N-1);
• on peut commencer à relier les tronçons d'âmes 10 de l'élément (N) à ceux de l'élément (N-1);
• on met en place le coffrage et le ferraillage du hourdis inférieur de l'élément (N+1);
• on met en place les tronçons d'âmes de l'élément (N+1);
• on met en place le coffrage et le ferraillage du hourdis supérieur de l'élément (N+1);
• on finit de relier les tronçons d'âmes de l'élément (N) à ceux de l'élément (N-1);
• on coule le béton des hourdis inférieur et supérieur de l'élément (N+1 );
• on relie les ourdis inférieur et supérieur de l'élément (N+1) respectivement aux hourdis correspondants de l'élément (N).

Similarly, for the construction of a structure by successive cantilevered structural elements assembled and built on site, we proceed as follows:

• pour the concrete of the lower 4 and upper 3 slabs of an element (N):
• connecting the lower 4 and upper 3 slabs of the element (N) respectively to the corresponding slabs of the element (N-1);
• it is possible to start connecting the sections of cores 10 of the element (N) to those of the element (N-1);
• the formwork and the reinforcement of the lower slab of the element (N + 1) are put in place;
• the core sections of the element (N + 1) are put in place;
• the formwork and the reinforcement of the upper slab of the element (N + 1) are put in place;
• we finish connecting the sections of souls of the element (N) to those of the element (N-1);
• the concrete is poured from the lower and upper slabs of the element (N + 1);
• the lower and upper warps of the element (N + 1) are connected respectively to the corresponding warps of the element (N).

This process is illustrated by FIGS. 6 to 9 which relate to a bridge beam constructed by successive structural elements (N-1), (N), (N + 1) produced on site by cantilever, that is to say cantilevered, by means of a gantry of any known mobile type and bearing on the parts already built, and which it is unnecessary to describe here.

The situation shown in Figure 6 is as follows. The sections of upper 3 and lower 4 slabs of the structural element (N) have been poured, set and are connected to those of the element (N-1). The core sections 10 of the element (N) are being welded to the core sections 10 of the element (N-1). Work to prepare the element (N + 1) has started.

The lateral formwork 20, the transverse formwork 21 and the formwork 22 of the bottom of the section of the lower slab of the element (N + 1) are in place and are supported by the frame 23 carried by the above-mentioned gantry (not shown). The reinforcements 24 of this section of slabs are also in place and are connected to the concrete rods 25 left waiting and projecting relative to the section of lower slabs 4 of the element (N). A support beam 26, one end of which is embedded in the slab of the element N also projects into the middle of the reinforcements 24.

We approach by means of a lifting device (not shown) and slings 27 the metal beam element 6 of the structural element (N + 1). The core section 10 is in this example a pleated sheet connected to the upper sole 8 and lower sole sections 9. The latter bear on their outer face connection elements 28 of any type.

Pending circles 29 also project from the upper section of slabs 3 of the element (N).

In FIG. 7, the metal beam element 6 of the element structure (N + 1) is in place.

As seen in Figure 9, a second beam member 30 rests on the beam 26 for adjusting the position of the bottom flange section 9. At the other end of this section 9 a cylinder 31 allows to adjust the level of it.

As seen in Figure 8, an adjustment system with a threaded rod 32 allows the adjustment of the upper part of the metal beam element.

Once this element is adjusted in position, it suffices to put in place the formwork elements and the reinforcements necessary for the upper section of slabs.

We will wait for the end of the welding of the sections of cores 10 of the element (N) on those of the element (N-1) before pouring the concrete of the sections of slabs 3, 4 of the element (N + 1 ).

In the case where the elements of the mixed elongated structure are adapted to be connected to each other by means of prestressing cables, prestressing cables are provided connecting respectively the upper and lower slabs of the structural element ( N) to those of the structural element (N-1) and put these prestressing cables in tension before starting to connect the sections of cores of the element (N) to those of the element (N- 1), while starting the preparation of the element (N + 1).

We have thus described a metal beam element and a method of implementing this element which make it possible to produce a mixed elongated structure of cross section of the box type under excellent conditions of cost and duration of the construction site.

In particular, it is thus possible to produce an elongated mixed prestressed structure with pleated sheet cores, by producing and assembling on the spot, to each other, cantilevered structural elements. Such a mixed structure thus has all the advantages described in EP-A-0 283 383, while presenting all the advantages of a cantilever construction, with the possibility of carrying out all the operations of assembling the cores of an element , for example by welding, in mask time during the operations of preparation of the concrete parts of the next element.

Of course, the invention is not limited to the modes of embodiment which has just been described, and many changes and modifications can be made to them without departing from the scope of the invention, defined by the appended claims.

Claims (11)

1. A structural element (1, 2) to achieve, by means of successive structural elements (1, 2), a hybrid elongate structure with a box-shaped type cross section including a concrete upper slab and a concrete lower slab connected to each other over their entire length by at least two metal girders, characterised in that the structural element includes at least two metal girder elements (5, 6), an upper slab section (3) and a lower slab section (4), in that each metal girder element (5, 6) includes a web section (7, 10) fixed along its longitudinal edges to a upper flange section (8) and to a lower flange section (9), respectively, the upper (8) and lower (9) flange sections being fixed to the upper slab section (3) and lower slab section (4), respectively, and in that each flange section (8, 9) of said metal girder element (5, 6) includes, on its outer surface (8a, 9a) opposite to the web section (7, 10), connection elements (12, 13, 28) adapted to be imbedded in concrete and connecting the flange sections to the concrete of the corresponding slab, the number, dimensions and positions of said connection elements of a flange section (8, 9) being predetermined such that said elements are capable of withstanding the tensile stresses exerted on said flange section (8, 9) by the concrete of the corresponding slab section (3, 4) of the same structural element (1, 2) in the course of the deformations anticipated for said structure.
2. A structural element according to claim 1, characterised in that the connection elements (12, 13, 28) comprise angle sections (12) welded on the outer surface (8a, 9a) of each flange (8, 9).
3. A structural element according to claim 1 or 2, characterised in that the connection elements (12, 13, 28) comprise head bolts (12) welded at their end opposite to the head on the outer surface (8a, 9a) of each flange (8, 9).
4. A structural element according to one of claims 1 to 3, characterised in that the web section (7) is a flat plate.
5. A structural element according to one of claims 1 to 3, characterised in that the web section (10) is a folded plate.
6. A structural element according to one of claims 1 to 5, characterised in that the length of each of the flange sections (8, 9) is substantially inferior to the corresponding length of said metal girder element (5, 6).
7. A method to implement the structural element (1, 2) according to one of claims 1 to 6 so as to build a hybrid elongate structure with a box-shaped type cross section by means of successive structural elements (1, 2) assembled after the other, wherein the slab sections (3, 4), on the one hand, and the web sections (7, 10), on the other hand, of said structural elements (1, 2) are connected together, characterised in that the flange sections (8, 9) are left separated from one another, and in that the slab sections (3, 4) are linked together using predetermined linkage means (35, 36, 37, 38) adapted to transmit, from one structural element (1, 2) to an adjacent structural element (1, 2), all the longitudinal stresses generated within the elongate structure during its use.
8. A method according to claim 7, to build a structure by assembling prefabricated hybrid structural elements one after the other, characterised in that first the upper and lower slab sections (3, 4) of an element (N) are linked to the upper and lower slab sections (3, 4) of the previous element (N-1), and then the web sections (7, 10) of the element (N) are linked to those of the previous element (N-1).
9. A method according to claim 7, to build a structure by means of successive, cantilevered structural elements (1, 2) assembled and built on-site, characterised in that it includes the following steps:

   - pouring the concrete of the lower (4) and upper (3) slabs of an element (N);

   - linking the lower (4) and upper (3) slabs, respectively, of the element (N) to the corresponding slabs of the previous element (N-1);

   - starting linking the web sections (7, 10) of the element (N) to those of the previous element (N-1);

   - installing the formwork (20, 21, 22) and reinforcement (24) of the lower slab (4) of the next element (N+1);

   - installing the formwork and armouring of the upper slab (3) of the next element (N+1);

   - finishing linking the WEB sections (7, 10) of the element (N) to those of the previous element (N-1);

   - pouring the concrete of the lower (4) and upper (3) slabs of the next element (N+1);

   - linking the lower (4) and upper (3) slabs of the next element (N+1) to the corresponding slabs (3, 4) of the element (N), respectively.
10. A method according to one of claims 7 to 9, wherein the hybrid elongate structure elements (1, 2) are adapted to be linked to one another by means of pretensioning cables, characterised in that pretensioning cables are provided linking the upper (3) and lower (4) slabs of the structural element (N) to those of the previous structural element (N-1), respectively, and in that these pretensioning cables are tensed before the linking of the web sections (7, 10) of the element (N) to those of the previous element (N-1) is begun.
11. A hybrid elongate structure with a box-shaped type cross section including a concrete upper slab and a concrete lower slab connected to each other over their entire length by at least two continuous metal girders, particularly road or railway bridge girders, characterised in that it is achieved by implementing a method according to one of claims 7 to 10.

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