EP1881114A2 - Method of manufacturing a filled individual construction element intended for a civil engineering structure - Google Patents

Abstract

The method involves assembling independent panels between their vertical lateral sides to form a parallelepiped shaped outer metallic box (2). Handling units handling a parallelepiped shaped gabion type individual construction element (1), are installed by associating the units with a panel forming the bottom of the box. The box is positioned in a filling formwork (21), and filled with a filling material (34) e.g. stone, while maintaining the units accessible by an element`s upper side. Compaction is ensured by vibrations of the material. The box is closed with a horizontal upper cover (6).

Description

Technical area

The present invention relates to a method of manufacturing an individual element of filled construction. The invention relates to such an individual building element, filled beforehand. Such a pre-filled individual element is intended for the realization of works in the field of civil engineering and public works.

More and more construction techniques in the field of civil engineering and public works make use of individual units or building elements. These individual elements are used to form retaining walls, noise barriers, bridge stacks, stone protection slips, landslides and landslides, protective structures in the military field or roadway reinforcement works, canal banks, rivers, rivers and seashores, and others.

In general, these individual elements are made from cage structures containing a filling material, and generally known as "gabions". The dimensions of these gabions can be very variable, depending on the size of the structure. These gabions are filled with materials, such as stones, crushed pebbles, materials with elastoplastic properties, such as tires, and others.

The gabions consist of a cage which forms a container taking a well-known parallelepipedal shape. The parallelepiped has a bottom, four vertical side faces unfolding upwards from the bottom and a horizontal top cover, closing the container once filled by the material. These gabion cages are made with double twisted wire mesh, welded mesh or steel reinforcement bars, used independently or in combination.

Depending on the situation, the gabion cages are delivered to the civil engineering or public works site, with their side faces, their bottom and their cover. separate pieces, or preassembled. In the first case, the gabions require a complete assembly step by assembling the separate pieces. In the second case, the gabions require an unfolding step, to move from the starting state to flat to the state of container ready to be filled with a material. In the two aforementioned cases, the gabions are then assembled together in the book.

Large quantities of materials needed for filling must be present or sent to the work site. To improve on-site installation and increase production speeds, as well as ease installation in cramped areas, some manufacturers have offered pre-filled gabions on the market.

State of the art

For example, we know from the documents EP-1,186,719 and EP-1.505.211 a gabion consisting of flat parts connected to each other, so as to form a bottom, side faces and a cover. These flat parts are made from welded mesh. The gabion thus formed retains its shape when filled, when it is lifted, transported and put in place on the site.

However, such a gabion has the first disadvantage of presenting significant risks of rupture, at the level of the welds, in particular during high loads. A second disadvantage of the gabion is that it has a relatively high curb weight, because of the diameter of the wires. lattice which is calculated to obtain sufficient strength. The faces and bottom of the gabion filled must not deform or break during the handling and transport phases. A gabion with a container volume substantially equal to 1 m ³ has a mass of about 1.7 t. In addition, these gabions are expensive to produce ..
Many works made with gabions must have characteristics of flexibility or deformability important given the environment of the construction, particularly with regard to hydraulic structures, or those made on compressible soils. However, welded mesh gabions do not have these characteristics of flexibility. In addition, the welded mesh is very rigid, which can cause problems when it is desired to assemble elements together to form a monolithic structure.

We know from the document JP 2002-97616 a method of filling a gabion which consists of pouring the filler material by means of a machine of the excavator type. After filling, the material is packed with the bucket of the excavator to compact it. Such a gabion must then be transported to its place of implantation by a specific material, comprising a plurality of hooks which pass through the mesh. The pulls exerted on the mesh during its transportation inevitably cause deformation of the gabion, or force to use oversized son.

Presentation of the invention

A main problem to be solved by the invention is to develop a method of manufacturing a gabion type of individual building element, pre-filled with materials, can be delivered and installed on a construction site. A second problem is that of providing an individual building element having means for improving its resistance to transport and handling in the filled state. A third problem is that of producing an individual element of double twist wire construction, which is simultaneously, load-resistant, not highly deformable but sufficiently flexible, and can be easily handled. Another problem is to add to an individual building element handling means, reinforcement means and protection means during filling.

The invention therefore relates to a method of manufacturing an individual building element for the realization of a civil engineering work. The element forms a container adapted to receive a filling material. The container is delimited by an outer envelope, substantially parallelepipedic, having a horizontal bottom, four vertical side faces and a horizontal top cover. The outer casing is made of a double twist lattice of a given type of mesh.

• à assembler les panneaux entre eux, afin de constituer l'enveloppe extérieure ;
• à mettre en place des moyens de manutention de l'élément, en les associant au panneau formant le fond de l'enveloppe ;
• à positionner cette enveloppe extérieure dans un coffrage de remplissage ;
• à remplir progressivement cette enveloppe extérieure avec le matériau de remplissage, tout en maintenant les moyens de manutention accessibles par la face supérieure de l'élément ;
• à assurer un compactage par vibrations dudit matériau de remplissage ; et
• à refermer cette enveloppe extérieure avec le couvercle supérieur horizontal.

In accordance with one aspect of the present invention, the method comprises the following steps:

• to assemble the panels together, to form the outer envelope;
• setting up means for handling the element, by associating them with the panel forming the bottom of the envelope;
• positioning this outer casing in a filling casing;
• gradually filling the outer casing with the filling material, while maintaining the handling means accessible by the upper face of the element;
• vibration compacting said filling material; and
• to close this outer envelope with the horizontal top cover.

In other words, the individual element of construction obtained by the implementation of the method has considerably improved technical characteristics of resistance. The mass of the filling material exerts forces which are taken up by the outer shell made of double twisted wire mesh. The diameter chosen for the wire constituting the grid allows optimum recovery of all the forces exerted mainly during the handling of the filled building element when it no longer rests on the ground. The handling means to be permanently integrated in the gabion are put in place before filling the latter, by mounting at the panel or panels forming the bottom of the gabion. In this way, they cross the entire thickness of the gabion to pass over the top of it when it is filled. The lifting of the gabion is thus authorized without causing traction on the wire mesh of the gabion, but not a force exerted on the lower face of the latter. The gabion thus produced is directly ready for use, transportable easily, and has a stable shape that is almost indeformable thanks to the compacting of the filling material.

In a particular embodiment, these handling means may comprise a rigid part held at the horizontal bottom and a flexible piece suitable for lifting, rectilinear, cooperating with the rigid part, and able to pass through the material. This rigid piece may be located below the bottom wall so that the flexible piece, for example a strap, is associated with the rigid piece, and through the bottom wall to go up through the gabion and emerge from the upper face to form a lifting point.

The use of a filling form ensures the maintenance of the outer casing, during its filling by the material, and then during compaction. The filled envelope thus retains its dimensional characteristics. The compaction taking place during or even after the filling homogenizes the entire mass found inside the envelope. The combination of technical characteristics of the different steps of the process makes it possible to obtain an individual element of geometric, technical and aesthetic homogeneous quality perfectly adapted to the construction of a civil engineering work.

Advantageously, in practice, the double twist netting is chosen so that, for the given type of mesh, it has a wire diameter (d) substantially greater than the wire diameter for a double twist wire defined by the NF EN 10223 standard. -3. In other words, contrary to the trend which aims to minimize the size of the wire to reduce the cost of the gabion, the invention aims to use a wire of greater diameter than that recommended by the standards in force, which allows ensure dimensional stability of the walls of the gabion, in particular after filling, during its transport.

dans laquelle les coefficients x₁, x₂, x₃, x₄ sont x₁ = 1,25.10^-5 ; X₂ = -2,875.10^-3 ; x₃ = 0,2325 ; x₄ = -3,6 , et D et d étant exprimés en mm.In practice, the wire diameter of the double twist wire may be a function of a mesh width of said double twist wire. The relationship between the wire diameter (d) and the mesh width (D) makes it possible to define the minimum values of the diameter of the wire for the method of the invention. The relationship between diameter (d) and width (D) can be: $$\mathrm{d}>{\mathrm{<figure-callout\; id="1"\; label="x"\; filenames="imgf0004.png"\; state="\{\{state\}\}">x</figure-callout>}}_1\mathrm{.}{\mathrm{<figure-callout\; id="3"\; label="D"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">D</figure-callout>}}^3+{\mathrm{x}}_2\mathrm{.}{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">D</figure-callout>}}^2+{\mathrm{x}}_3\mathrm{.}\mathrm{D}+{\mathrm{x}}_4;$$

wherein the coefficients x ₁ , x ₂ , x ₃ , x ₄ are x ₁ = 1.25 x 10 ^-5 ; X ₂ = -2.875.10 ^-3 ; x ₃ = 0.2325; x ₄ = -3.6, and D and d being expressed in mm.

• 2,5 mm et 3,5 mm, et de préférence voisin de 2,7 mm pour une largeur de maille (D) du grillage double torsion sensiblement égale à 50 mm ;
• 2,8 mm et 4,5 mm, et de préférence voisin de 3,0 mm, pour une largeur de maille (D) du grillage double torsion sensiblement égale à 60 mm ;
• 3,1 mm et 6,0 mm, et de préférence voisin de 4,0 mm, pour une largeur de maille (D) du grillage double torsion sensiblement égale à 80 mm ;
• 3,5 mm et 7,0 mm, et de préférence voisin de 4,2 mm, pour une largeur de maille (D) du grillage double torsion sensiblement égale à 100 mm.

The wire diameter (d) of the double twist wire may be substantially between:

• 2.5 mm and 3.5 mm, and preferably close to 2.7 mm for a mesh width (D) of the double twist mesh substantially equal to 50 mm;
• 2.8 mm and 4.5 mm, and preferably close to 3.0 mm, for a mesh width (D) of the double twist grid substantially equal to 60 mm;
• 3.1 mm and 6.0 mm, and preferably close to 4.0 mm, for a mesh width (D) of the double twist grid substantially equal to 80 mm;
• 3.5 mm and 7.0 mm, and preferably close to 4.2 mm, for a mesh width (D) of the double twist mesh substantially equal to 100 mm.

The filling form may advantageously have a modular structure. The modular structure can be made from panels of different sizes joined together. This structure can thus vary according to the dimensions of the desired outer envelope.

The filling material may have a particle size substantially equal to 80-130 mm. Favorably, the step consisting in providing vibration compacting of the filling material can be adapted to be optimized by implementation in two cycles at different frequencies. This implementation can be done with a vibrating table, on which is placed the filling form and the outer envelope.

The method may include a further step, sandwiched between the step of assembling the panels and the step of positioning the outer shell in the fill form. Advantageously, this step may consist in assembling at least one reinforcing tie rod intended to connect together two of the four vertical lateral faces, so as to ensure reinforcement of the container.

The method may comprise an additional step, sandwiched between the step of assembling the panels and the step of positioning the outer envelope in the fill form. This step may preferably consist of assembling at least one vertical transverse partition wall. The wall or diaphragm may be deployed between two of the four vertical side faces, so as to form at least two separate volumes inside the outer casing. The same container can include a multiplicity of volumes.
The method may comprise an additional step, sandwiched between the step of positioning the outer shell in the fill form and the step of filling the outer shell with the filler material. This step may consist in putting in tension the rectilinear part of the handling means, so as to make it pass through the filling material substantially vertically. In this way, the part that will allow the lifting remains in a position that ensures a vertical uprising of the gabion, without tilting.

Advantageously, the method may comprise an additional step, interposed between the step of positioning the outer casing in the fill casing and the step of filling the outer casing with the filling material. The building element can be temporarily protected during the filling phase against the filling material which falls inside the cage. The protection may be aimed at the upper edge of the transverse partition wall or the tie rod or rods. This step may consist in positioning removable protective means against the filling material, placed on an upper edge of the vertical transverse partition wall or walls and / or on the transverse tie rod or bars.

Advantageously in practice, the gabion can be formed by assembling two subassemblies in a generally U-shaped configuration, each formed by the combination of several panels constituting at least two vertical lateral and one bottom face, the panels of the bottom faces. two subsets being superimposed.

Preferably, the panel forming the bottom of the first subassembly comprises a double twist grid having mesh oriented perpendicular to the mesh of the double twist of the panel forming the bottom of the second subassembly.

Brief description of the figures

• la Figure 1 représente une vue synoptique en perspective éclatée de la première et de la deuxième étape du procédé de fabrication d'un élément individuel de construction conformément à l'invention ;
• la Figure 2 représente une vue en perspective de l'élément assemblé selon la Figure 1 ;
• la Figure 3 représente une vue agrandie du détail A de la Figure 1, présentant le grillage double torsion ;
• les Figures 4 à 6 représentent des vues en perspective d'un élément, avec des tirants de renfort, selon une première, une deuxième et une troisième variante de réalisation ;
• la Figure 7 représente une vue en perspective d'un élément, muni des moyens de renfort, d'une paroi de séparation transversale verticale et des moyens de protection amovibles utilisés lors du remplissage ;
• la Figure 8 représente une vue en perspective des moyens de protection amovibles selon une autre variante ;
• la Figure 9 représente une vue en perspective d'un coffrage de remplissage ;
• la Figure 10 représente une vue en perspective partielle des moyens de maintien de l'élément à l'intérieur du coffrage de remplissage ;
• la Figure 11 représente une vue en perspective partielle des moyens de manutention insérés dans l'élément ; et
• la Figure 12 représente une vue synoptique en perspective des étapes de remplissage et de compactage du matériau.
• la Figure 13 représente une vue en perspective éclatée d'un gabion construit selon une deuxième forme de réalisation ;
• la Figure 14 représente une vue en perspective de l'élément assemblé selon la forme de réalisation de la Figure 13 ;
• la Figure 15 représente une vue agrandie du fond un gabion de la figure 14 ;

The invention will be better understood and its various advantages and different characteristics will become more apparent in the following description, of the nonlimiting exemplary embodiment, with reference to the appended diagrammatic drawings, in which:

• Figure 1 shows an exploded perspective view of the first and second steps of the method of manufacturing an individual building element according to the invention;
• Figure 2 shows a perspective view of the assembled element according to Figure 1;
• Figure 3 shows an enlarged view of detail A of Figure 1, showing the double twist wire;
• Figures 4 to 6 show perspective views of an element, with tie rods, according to a first, a second and a third embodiment;
• Figure 7 shows a perspective view of an element, provided with the reinforcing means, a vertical transverse partition wall and removable protective means used during filling;
• Figure 8 shows a perspective view of the removable protection means according to another variant;
• Figure 9 shows a perspective view of a filling form;
• Figure 10 shows a partial perspective view of the means for holding the element inside the filling casing;
• Figure 11 shows a partial perspective view of the handling means inserted in the element; and
• Figure 12 is a perspective schematic view of the steps of filling and compaction of the material.
• Figure 13 is an exploded perspective view of a gabion constructed according to a second embodiment;
• Figure 14 is a perspective view of the assembled member according to the embodiment of Figure 13;
• Figure 15 is an enlarged view of the bottom of a gabion of Figure 14 ;

Detailed description of the invention

As illustrated in Figures 2 to 7, an individual building element (1) is intended to produce a civil engineering works or public works. This element (1), initially empty, will be filled with filling materials and delivered to its site of use. This element (1) is in the form of a substantially parallelepiped gabion.

The gabion includes a container in the form of an outer metal cage (2), adapted to receive the materials. The cage (2) is made of double twist wire (see Figure 3). The cage (2) comprises a bottom (3), four lateral faces (4) and a cover (6). The bottom (3), the side faces (4) and the cover (6) are each constituted by an independent panel (7). It should be noted that one can use a folded panel, so as to obtain for example simultaneously the bottom (3) and two side faces (4).

In a first step of the method of manufacturing the gabion according to the present invention, the panels (7) are made from double twisted wire (8). Due to its intrinsic structure, and as shown in FIG. 3, the double twisted mesh (8) has a repetitive hexagonal mesh (9).

Table 1 below gives the values of the maximum diameters (d) for different mesh widths (D), according to standard NF EN 10223-3 and which must be respected for the manufacture of gabion panels. <u> Table 1 </ u> Mesh width (D), in mm Max diameter of wire (d), in mm 50 2.4 60 2.7 80 3 100 3.4

According to the invention and in the choice operating in the first. step, for good mechanical performance of the cage (2), the double twisted mesh (8), used for the four vertical side faces (4) and the bottom (3), has a wire diameter (d) significantly greater to the wire diameter for a double twist wire defined by the standard NF EN 10223 - 3. This choice of diameter confers very important advantages over the fences known to date.

Indeed, comparative tests show that the tensile strength and the punching resistance are much higher than those obtained with grids made from wire in mesh / wire combinations recognized by the current standard. A similar steel composition, and similar geometric properties of mesh, these resistors are actually better than several factors compared to wire mesh according to the standard. These advantages advantageously compensate for the complexification of the process of making the screen, which requires weaving machines capable of processing large diameter wires, with therefore much higher mechanical forces developed.

The wire diameter (d), in mm, follows the following relationship, according to the mesh width (D), in mm, d = f (D): d> 1.25.10 ^-5 .D ³ - 2,875.10 ^{- 3} .D ² + 0,2325.D - 3.6.
Table 2 below gives the average and preferred values of the diameters (d) for different mesh widths (D) according to the present invention. <u> Table 2 </ u> Mesh width (D), in mm Wire diameter (d) average, in mm Preferred wire diameter (d), in mm 50 2.5 - 3.5 2.7 60 2.8 - 4.5 3.0 80 3.1 - 6.0 4.0 100 3.5 - 7.0 4.2

As a very preferred example, the meshes used for the gabions of the present invention have dimensions of the order of 4.0 mm for a width of 80 mm.

In a second step of the method of manufacturing the gabion according to the present invention, the four panels (7) constituting the four lateral faces (4) are secured (Arrows A in Figure 1) by their edges common to the bottom panel (7) ( 3). The panel (7) forming the lid is then secured to an upper edge of one of the side faces. The fastening is done through folding, stapling, ligatures, or any other manual or automatic means. The cage (2) ready to be filled with materials is now constituted.

In a third optional step of the gabion manufacturing method according to the present invention, the cage (2) comprises (see FIGS. 2 to 7) reinforcements in the form of series of transverse tie rods (11). These series (11) are formed by rods or metal rods (12), provided with a hook (13) at their ends, so as to be hooked to the double twist lattice of the side faces (4). The tie rods (12) extend between the opposite lateral faces (4). The tie rods also extend longitudinally, that is to say perpendicular to the transverse tie rods.

In a first variant embodiment (see FIG. 4), for a cage (2) having dimensions equal to 1 m in width, 1 m in height and 1 m in depth, two plies (11) of six tie rods (12) are hung, each being maintained at a level one third of the height. In this case, a sheet comprises three transverse tie rods perpendicular to three longitudinal tie rods. You can count twelve rods per m ^3.

In a second variant embodiment (see FIG. 5), for a cage (2) having dimensions equal to 1 m in width, 0.5 m in height and 1 m in depth, a ply (11) of six tie rods (12) ) is hung at a level halfway up. In this case, the sheet (11) comprises three transverse tie rods perpendicular to three longitudinal tie rods.

In a third variant embodiment (see FIG. 6), for a cage (2) having dimensions equal to 1 m in width, 1 m in height and 0.5 m in depth, two plies (11) of four tie-rods (12) ) are hung, each being held at a level one third of the height. In this case, a sheet (11) comprises three transverse tie rods perpendicular to a longitudinal tie rod.

In a fourth embodiment (see Figure 7), the tie rods (12) are deployed between two of the four opposite side faces (4).

In a fourth optional step of the gabion manufacturing method according to the present invention, a diaphragm or vertical intermediate wall (14) is assembled (see the embodiment variant of FIG. 6) inside the cage (2). This wall reported (14) serves to reinforce the gabion (1). This added wall (14) also serves to separate the cage (2) transversely into two separate compartments or volumes (16).
This intermediate wall (14) thus extends between two of the four lateral faces (4), preferably between the opposite lateral faces. The intermediate wall (14) is also made of double twist wire. The double twist grid used for the panel of this intermediate wall (14) can follow the diameters defined by the standard NF EN 10223-3.

In a fifth optional step of the method of manufacturing the gabion according to the present invention (see Figure 11), handling means (17) are positioned by being fixed at the bottom (3) of the cage (2). These handling means (17) are used to lift the cage (2) and the filled gabion (1).

These handling means (17) comprise a first rigid piece, for example a bar (18) of 30 mm diameter for 500 mm long. The bar (18) is inserted into the bottom (3) of the cage (2). A second flexible piece, for example a cable or a lifting strap (19), is attached to the first rigid piece (18). The bar (18) can be placed under the bottom wall (3) of the gabion, so that the strap wrapped around the bar forms a loop which makes it integral with the bar (18) or so that the bar simply pass through the strap then held in tension to prevent any movement. According to the methodology used for the preparation of the gabion, this bar can be held under the bottom (3) of the gabion by various means to allow the manipulation of the gabion after the establishment of the bar (18), in particular during the movement of the gabion to the filling formwork. This maintenance can be achieved by an additional portion of wire placed below the bar, and attached to the bottom wall (3).

In a sixth step of the gabion manufacturing method according to the present invention, the cage (2) is positioned in a formwork (see Figure 9) for filling (21). The formwork (21) allows to form and thus maintain the structure of the cage (2) during the filling step that follows. The formwork (21) is modular consisting of panels (22), which are assembled to each other by screws, by hinges and doors (23). The configuration of the formwork (21) makes it possible to fill one or more cages (2) of the same format or of different formats. By way of example, variations of possible formats are with the following dimensions: 1 m or 2 m wide for 0.5 m or 1 m high for 0.5 m or 1 m deep.

In an optional seventh step of the method of manufacturing the gabion according to the present invention, removable protective means (24) against the falling of the filling material are placed (arrow P in Figure 7) on areas that may be damaged. These areas are the upper edge (26) of the transverse partition wall (14) and the tie rods (12).

These protection means (24) typically metallic, can take the form of an angle iron, flat irons, bars or tubes, round or square, branched (Figure 8) or not, so as to partially or completely cover the areas fragile.

In an optional eighth step of the method of manufacturing the gabion according to the present invention, before the filling operation of the cage (2) which follows, holding means (27) make it possible to keep the four lateral faces (4) pressed against the corresponding inner walls of formwork (21), during the subsequent filling (see Figure 10). The holding means (27) are arranged at different points, for example vertically and transversely on each face (4).

The holding means (27) are in the form of bars (28) placed outside the formwork (21). These bars (28) have a plurality of hooks (29) gripping the double twisted mesh (8) of the cage (2) through slots (31) provided in the filling formwork (21). These holding means (27) thus avoid a potential curvature of the lateral faces (4) inwardly during filling.

In an optional ninth step of the method of manufacturing the gabion according to the present invention, before the filling operation of the cage (2) which follows, the strap (19) is tensioned and is held vertically by specific means tensioning. The strap (19) passes through the filling material approximately vertically and is permanently embedded in the filled gabion (1).

The tensioning means comprise a transverse bar (32) passing through a loop formed by the strap (19). The bar (32) is lifted upwards (arrows L in Figure 11) by two mechanical systems, of type foot (33), located at the ends of the bar (32) and on or outside the formwork (21).
In a tenth step of the gabion manufacturing method according to the present invention, the cage (2) is progressively filled (see arrow F in Figure 12) with filling material (34). The filling is carried out by means of a trolley (36) provided with a bucket (37). It is an efficient way to fill the place of production of filling equipment in the vicinity of different industrial sites and varied environments, such as quarries and construction sites.

The bucket (31) has a specific width adapted to the width of the formwork (21), for example 1.80 m for a formwork of 2 m. The volume of the bucket (37), for example equal to 1 m ³ , minimizes the filling time. The bucket (37) finally ensures a good distribution of the stones in the entire cage (2).

The filling material used (34) is gabion stone. In terms of hardness and gelling, the material meets the NF-EN-13383 standard. In terms of particle size, the material meets the standard entitled "Execution of gabion structures" NF-P 94 325 - 1. The particle size used is reduced to 80-130 mm, in order to increase the homogeneity of the filling and decrease the spaces being constituted during filling and compaction that follows. The filling with materials (34) must be done carefully, in successive layers and with vibro-compaction. The standard NF-P 94 325 - 1 imposes the rules of the art concerning assembly, assembly and filling of gabions. In fact, the stability of the gabion, and thus of the work formed with these gabions, depends on the way in which the materials have been chosen, and then placed inside this container.

In an eleventh step of the gabion manufacturing method according to the present invention, the cage (2) inserted into the formwork (21) and in progress and at the end of the filling process, is subjected to vibrations. To do this, the formwork (21) is placed on a vibrating table (38). The formwork (21) thus makes it possible to maintain the lateral walls (4) of the cage (2), to prevent their displacement consecutive to the vibrations necessary to compact the filling material (34).

The vibrating table (38) is dimensioned to vibrate a total mass ranging between 2 and 4 tons. The vibration cycle consists of two successive phases, each at a specific frequency. These two different levels of vibration make it possible to increase the compaction cohesion of the filling material (34), because of their impact on the different sizes and masses of the stones constituting this material (34).

In a particular embodiment, the vibrating table (38) used in the filling process has a welded structure based on profiles. The table (38) is equipped with two electric vibrators, for a load to vibrate of the order of 3.5 tons. The table top (38) is mounted on six shock absorbers of the damping rails type.

In a twelfth step of the gabion manufacturing method according to the present invention, the cage (2) is closed with the horizontal top cover (6). The double twist grid used for the panel of this cover (6) can follow the diameters defined by the standard NF EN 10223 - 3.

In a thirteenth step of the gabion manufacturing method according to the present invention, the gabion (1) is raised and removed form the formwork (21). The pre-filled gabion (1), obtained in accordance with the implementation of all or some of the steps described, is ready to be delivered to its location site.

Regardless of the manufacturing method, the gabion can be made according to a construction variant illustrated in FIGS. 13 to 15. Thus, as illustrated in FIG. 13, the gabion is constituted by the assembly of two subassemblies (52, 53) presenting each of them having a generally U-shaped configuration. The first subassembly (52) is formed by a single folded wire pan to form two lateral faces (54,58) and a bottom face (56). The second subassembly (53) is similarly constructed to form two front (57) and rear (55) faces connected by a bottom face (59), and also includes an additional face (61) for forming the lid of the gabion. This cover may however be formed of a third insert.

After assembly, and as illustrated in FIG. 14, the two subassemblies (52, 53) are arranged in such a way that their bottom faces (56, 59) overlap each other. It is possible to interpose between these two bottom faces the rigid bar (18) or more generally a portion of the handling means for lifting the gabion.

Preferably, the two faces (56, 59) forming the bottom of the gabion are assembled together so as to have meshes (62, 63), or more precisely zones of torsion of the wires, defining a direction of resistance. preferential (R), perpendicular to each other. By being positioned at right angles, the conjunction of the meshes (62) of the first subassembly (52) and the second subassembly (53) increases the resistance of the bottom obtained.

The lateral faces (54,55,57,58) have meshes all oriented in the same direction, oriented vertically, when the cage is assembled. As a result, because of the weight of the gabion filled, the forces acting on the bottom are distributed homogeneously on each of the lateral faces.

The present invention is not limited to the embodiments described and illustrated. Many modifications can be made, without departing from the scope defined by the scope of the set of claims.

Claims (14)

A method of manufacturing an individual building element (1) for producing a civil engineering structure, forming a container adapted to receive a filling material (34) delimited by an outer shell (2), substantially parallelepipedic, having a horizontal bottom (3), four vertical side faces (4) and a horizontal top cover (6), made of a double twist grid (8) of a given mesh type (9), comprising the successive steps of: - Assembling the panels together (4) to form the envelope (2); - Set up handling means (17) of the element (1), associating them with the panel forming the bottom of the envelope; - positioning said casing (2) in a filling casing (21); progressively filling said envelope (2) with the material (34), while keeping the handling means accessible by the upper face of the element; - to compact vibration of said material (34); and - To close the envelope (2) with the horizontal top cover (6). Process according to Claim 1, in which the double twisted mesh (8) has, for the given type of mesh (9), a wire diameter (d) substantially greater than the wire diameter for a double twist grid defined by the NF standard. EN 10223-3; Method according to claim 2, characterized in that the wire diameter (D) of the double twist wire (8) is a function of a mesh width (D) (9) of said double twisted wire (8), according to the relation: $$\mathrm{d}\mathrm{>}{\mathrm{x}}_{\mathrm{1}}\mathrm{.}{\mathrm{D}}^{\mathrm{3}}\mathrm{+}{\mathrm{x}}_{\mathrm{2}}\mathrm{.}{\mathrm{D}}^{\mathrm{2}}\mathrm{+}{\mathrm{x}}_{\mathrm{3}}\mathrm{.}\mathrm{D}\mathrm{+}{\mathrm{x}}_{\mathrm{4}}$$

in which x ₁ = 1.25 × 10 ^-5 ; x ₂ = -2.875.10 ^-3 ; x ₃ = 0.2325; x ₄ = -3.6; and
D and d are expressed in mm. Method according to claim 2 or 3, characterized in that the wire diameter (1) of the double twist wire (8) is substantially: between 2.5 mm and 3.5 mm, preferably substantially equal to 2.7 mm, for a width (D) of mesh (9) of the double twisted mesh (8) substantially equal to 50 mm, between 2.8 mm and 4.5 mm, preferably substantially equal to 3.0 mm, for a width (D) of mesh (9) of the double twisted mesh (8) substantially equal to 60 mm, between 3.1 mm and 6.0 mm, preferably substantially equal to 4.0 mm, for a width (D) of mesh (9) of the double twisted mesh (8) substantially equal to 80 mm, - Between 3.5 mm and 7.0 mm, preferably substantially equal to 4.2 mm, for a width (D) mesh (9) of the double twisted mesh (8) substantially equal to 100 mm. Method according to any one of the preceding claims, characterized in that the formwork (21) has a modular structure, made from panels of different dimensions joined together (22), depending on the dimensions of the envelope (2) . Process according to any one of the preceding claims, characterized in that the filling material (34) has a particle size substantially equal to 80-130 mm. Method according to one of the preceding claims, characterized in that the step of vibration compacting the material (34) is carried out in two cycles at different frequencies, with a vibrating table (38) on which is placed the formwork (21) and the envelope (2). Method according to one of the preceding claims, characterized in that it comprises a further step, interposed between the step of assembling the panels (7) and the step of positioning the envelope (2) in the formwork (21), consisting of assembling at least one reinforcing tie rod (12) intended to connect together two of the four vertical lateral faces (4). Method according to one of the preceding claims, characterized in that it comprises a further step, interposed between the step of assembling the panels (7) and the step of positioning the envelope (2) in the formwork (21), comprising assembling at least one vertical transverse partition (14), extending between two of the four vertical side faces (4), so as to form at least two separate volumes (16) inside the envelope (2). A method according to claim 1, characterized in that the handling means (17) have a rigid part (18) associated with the level of the horizontal bottom (3) and a flexible piece suitable for lifting (19), rectilinear, cooperating with the part rigid (18), and able to pass through the material (34). Method according to claim 10, characterized in that it comprises a further step, interposed between the step of positioning the envelope (2) in the formwork (21) and the step of filling the envelope (2) with the material (34), comprising tensioning the flexible part (19) so as to make it pass through the volume of the element substantially vertically. Method according to one of the preceding claims, characterized in that it comprises a further step, interposed between the step of positioning the casing (2) in the formwork (21) and the step of filling the casing (2). casing (2) with the material (34), consisting of positioning removable protection means (24) against the material (34), placed on an upper edge (26) of the vertical transverse partition (s) (14) and or on the transverse tie rod (12). Process according to Claim 1, characterized in that the element is formed by the assembly of two subassemblies in a generally U-shaped configuration, each formed by the combination of several panels constituting at least two lateral members. vertical and a bottom face, the panels of the bottom faces of the two subassemblies being superimposed. A method according to claim 13, characterized in that the panel forming the bottom of the first subassembly comprises a double twist grid (12) having meshes (13) oriented perpendicular to the mesh (13) of the double twisted mesh (12) of the panel forming the bottom of the second subset.

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