EP0824169A1 - Retention system for bulk material deposited on a sloped surface - Google Patents

Abstract

A retaining system, e.g. for soil for growing plants or a loose granular material on a sloping surface such as a roadside embankment (5), consists of a base layer (2) which is laid flat on the sloping surface and a series of supports (1) which project from the base layer and are located in rows. The supports extend through the whole thickness of the covering layer and lie perpendicular to the sloping surface. They can be made from a synthetic cellular material with hooks to engage with the base layer.

Description

The present invention relates to a restraint system of a material contribution of a certain thickness on a sloping structure. The technical area concerned is that of construction in general and in particular engineering It is sometimes useful and even necessary to cover a sloping structure built for example on the edge of road or forming the banks of a basin with a contribution of material of a certain thickness. This filler material can for example be topsoil, or a material granular not associated with a binder or whose binder will not taken only later.

In some cases, the conditions linked to the site do not not allow a direct implementation of this contribution for various reasons. For example, the slope may be too strong, so that the filler cannot hold himself on the sloping structure. Another reason may be linked to the presence of surface water, infiltration or frequent flooding of the structure. In other cases, the friction between the material of the sloping structure and the filler material may be insufficient, resulting in a risk of slipping.

A traditional technique to globally overcome this kind of disadvantages linked to the very nature of the site of the sloping structure is that of fascination consisting of planting stakes intended to retain bundles of wood. The addition of material which can be earth, is thus retained, so that the slope general is transformed into successive gentler slopes close to the stairs. We can rustically retain a material input on a work presenting a relatively steep slope.

However, due to the very non-constant nature of materials used (stakes and bundles of wood), this system traditional restraint by fascination can present weaknesses in some places. Indeed, all the stakes and all the bundles embedded in the filler material not undergo the same alteration, so that some stakes or some fagots can weaken with the time. In addition, since the bundles are made up completely heterogeneous branches by nature, all bundles do not have the same resistance. So is even for stakes, when made of wood. For these reasons, a traditional fascination using stakes and bundles of wood does not make it possible to obtain a system of reservoir with constant properties over the whole of the site of establishment.

A more modern technique to fight against erosion plans to use a geosynthetic tablecloth to increase the cohesion of the intake. This tablecloth is spread over the upper surface of the intake, which is thus armed. Over there the root system of the vegetation takes over to ensure the cohesion of the soil thus formed. This tablecloth can also be extended below the intake for the remember at the base. This increases friction at level of the structure / input interface. The tablecloth requires therefore significant tensile strength. However, in case the filler material does not have friction intrinsic and / or sufficient cohesion to form a massive sloping, there is a break in the supply. It's often the case in basins waterproofed by geomembrane where impoundment completely cancels cohesion.

There is another technique using materials alveolar synthetics to compensate for a lack of cohesion. However, their permeability and their height are limited (about 10 cm). Furthermore, in the case of application on structures with low friction, it is necessary to associate them with a system taking over the whole slip.

The prior art document WO 95/35417 defines a covering composed of a mesh placed on the ground on which is stapled a honeycomb structure. Staples thus connect the honeycomb structure to the mesh.

Document FR-2,591,064 discloses a fixing means of soil in which a honeycomb structure is arranged on a geotextile. However, for fixing the structure alveolar on the geotextile, stirrups of fixation that are planted in the ground across the geotextile. It is also the same for the geotextile. The purpose of the present invention is to overcome the disadvantages of the aforementioned prior art by defining a restraint system with features constant mechanical over the entire site of the sloping structure, regardless of the thickness of the supply of material. In addition, the restraint system according to the invention should easily be able to be implemented quickly and at low cost, regardless of the nature of the underlying soil.

• une nappe d'accrochage disposée à plat sur l'ouvrage en pente,
• des moyens de support accrochés à la nappe d'accrochage selon un réseau comprenant au moins une rangée disposée sensiblement transversalement à la pente,
• au moins un élément de retenue supporté par une, respectivement plusieurs rangée(s) de moyens de support et s'étendant sensiblement à travers la totalité de l'épaisseur de l'apport,

les moyens de support s'étendant sensiblement perpendiculairement à la pente sur une hauteur sensiblement égale à l'épaisseur de l'apport.To do this, the present invention provides a system for retaining a supply of material of a certain thickness on a sloping structure, comprising:

• a hanging ply disposed flat on the sloping structure,
• support means attached to the attachment ply according to a network comprising at least one row disposed substantially transversely to the slope,
• at least one retaining element supported by one or more rows of support means, respectively, and extending substantially across the entire thickness of the contribution,

the support means extending substantially perpendicular to the slope over a height substantially equal to the thickness of the intake.

According to one embodiment, said elements of retainers include a cellular foam material. We here uses a synthetic material with the structure alveolar of the prior art.

According to a preferred embodiment, said retainers include one, respectively, more than one fascine strip (s) supported appreciably perpendicular to the slope on one, respectively, several row (s) of support means extending substantially across the entire thickness of intake.

So compared to the traditional technique of fascination using planted stakes and bundles of wood, the present invention uses a tablecloth hooking on which the support means, which are the equivalent of traditional stakes, are not planted, but simply hung. On the other hand, instead traditional bundles of wood, the present invention provides using retaining elements arranged across the slope on the support means. With the restraint system according to the invention, the filler material is retained on the all or at least over almost its entire thickness by the retaining elements. So the filler material is so to speak compartmentalized between the retaining elements stretched across the slope. We thus improve considerably maintaining the filler material on the sloping structure. Any risk of slippage is thus completely avoided. The implementation of such a system restraint is also very simple: indeed, it does not requires the use of any suitable tool given that the fasteners of the support means on the sheet hooking and retaining elements on the means of support is carried out by simple mutual commitment without require clamping or fixing elements such as nails, screws or bolts.

Advantageously, the support means include hook means for hooking them to the tablecloth hanging. Thus, the support means are simply hooked to the hanging ply.

According to another characteristic, the support means include a base resting on the hanging ply.

Advantageously, the base comprises the hook means.

In addition, the support means comprise at least one plug extending substantially perpendicular to the slope over a height substantially equal to the thickness of intake. Thus, the hook means allow hold the base in place on the hanging ply, and the base 10 serves as a lift to hold the rod 15 approximately perpendicular to the slope. Rod 15 means support is the equivalent of the visible part of the stake of the traditional fascination technique, and the base 10 with its hook means 11 is the equivalent of the part planted with the stake of the technique of fascination traditional, but with the essential difference that the base of the support means need not be planted in force in the ground as was the case in the prior art technique, but just be crocheted to the hanging ply. This characteristic makes the implementation work much less painful given that it is no longer necessary to plant the stakes in the ground.

To facilitate the attachment of the support means to the hanging ply and the placement of the retained on the support means, the attachment ply and retainers include buckles hanging.

• une base de sustentation destinée à reposer sur une nappe d'accrochage étendue sur l'ouvrage en pente,
• des moyens de crochet pour l'accrochage de la base à la nappe d'accrochage, et
• au moins une fiche de support s'étendant sensiblement verticalement à partir de ladite base sur une hauteur sensiblement égale à l'épaisseur de l'apport pour supporter un élément de retenue.

The subject of the invention is also support means for a system for retaining a supply of material of a certain thickness on a sloping structure, comprising:

• a lifting base intended to rest on a hanging ply extended on the sloping structure,
• hook means for attaching the base to the attachment ply, and
• at least one support plug extending substantially vertically from said base over a height substantially equal to the thickness of the intake for supporting a retaining element.

• mise en place d'une nappe d'accrochage sur l'ouvrage en pente,
• accrochage de moyens de support à la nappe d'accrochage selon un réseau comprenant au moins une rangée disposée sensiblement transversalement à la pente,
• installation d'éléments de retenue supportés sensiblement perpendiculairement à la pente sur les rangées de moyens de support en s'étendant sensiblement à travers la totalité de l'épaisseur de l'apport.

The invention also relates to a method of implementing a system for retaining a supply of material of a certain thickness on a sloping structure, comprising the following steps:

• installation of a hanging ply on the sloping structure,
• attachment of support means to the attachment ply according to a network comprising at least one row disposed substantially transversely to the slope,
• installation of retaining elements supported substantially perpendicular to the slope on the rows of support means extending substantially across the entire thickness of the intake.

A detailed description will now be made in reference to the accompanying drawings, giving by way of example not limiting an embodiment of the present invention.

• la figure 1 est une vue en perspective d'une partie d'un ouvrage en pente équipé d'un système de retenue, selon l'invention ;
• la figure 2 est une vue en coupe verticale à travers un ouvrage en pente équipé d'un système de retenue selon l'invention ;
• la figure 3 est une vue de profil d'un des moyens de support selon une première forme de réalisation utilisé dans le système de retenue des figures 1 et 2 ;
• la figure 4 est une vue en perspective des moyens de support de la figure 3,
• la figure 5 est une vue en perspective d'un matériau synthétique alvéolaire,
• la figure 6 est une vue en perspective d'un moyen de support selon une seconde forme de réalisation préférée, et
• la figure 7 est une vue en perspective d'un ouvrage en pente équipé d'un système de retenue utilisant des moyens de support de la figure 6.

In the drawings:

• Figure 1 is a perspective view of part of a sloping structure equipped with a restraint system according to the invention;
• Figure 2 is a vertical sectional view through a sloping structure equipped with a restraint system according to the invention;
• Figure 3 is a side view of one of the support means according to a first embodiment used in the restraint system of Figures 1 and 2;
• FIG. 4 is a perspective view of the support means of FIG. 3,
• FIG. 5 is a perspective view of a cellular synthetic material,
• FIG. 6 is a perspective view of a support means according to a second preferred embodiment, and
• FIG. 7 is a perspective view of a sloping structure equipped with a restraint system using the support means of FIG. 6.

The restraint system which will now be described consists of three essential building blocks, namely, a fastening ply 2, support means 1, 1 ' attached to the hanging ply and one or more bands of fascine 3 mounted on the support means. Over there following, the support means will be more simply designated under the term "supports". The restraint system filler material can be used on any type of sloping structure on which the filler material does not cannot hold itself in place, for example for reasons for insufficient friction between the slope and the contribution or also of a lack of stability proper to intake.

A sloping structure, as there is on the edge of road, and designated in Figure 2 by reference 5, is first covered with a sheet 2 which is fixed by its upper edge at the top of the sloping structure 5 using any anchoring elements 22. Thus, the ply 2 extends flat over the entire slope of the structure 5. The sheet 2 can rest directly on the material of work 5, or possibly on a waterproof plastic film himself lying on the slope of the work. The tablecloth 2 can be a geosynthetic such as a geomembrane, a geocomposite, a geotextile or a geogrid. Tablecloth 2 is provided with hooking loops 21 or any other system allowing rapid attachment of elements. For example, in the case of a geogrid, the grid meshes will be used to hang the supports. For this reason, the tablecloth will be designated by the term of hanging ply 2. It must take up all the constraints exerted by the filler material 4 which will cover it.

According to a first embodiment, the supports 1, as can be seen more precisely in Figures 1, 3 and 4, include a base 10 forming a plane of lift and a plug 15 extending upwards starting from base 10 in a substantially orientation perpendicular to base 10. Base 10 should form a plane enough lift to give it sufficient stability considering the length of the rod 15, which, as will be seen if after, is a function of the thickness of the filler material covering the web attachment 2. The base 10 is formed of three sections of rods 12, 13 and 14 substantially forming a triangle so to have the most distant lift points possible. In addition, the base 10 includes means hooking in the form of a hook 11 formed at the end of the rod 12 in the form of a curved rod. The hook 11 of the base 10 is intended to be engaged in a hooking loop 21 of the hooking ply 2, as it can be seen in Figure 1. By this means, the support 1 is held in place on the hanging ply 2 with the plug 15 extending substantially perpendicular to the slope of the structure 5. Of course, the sheet 15 can have an orientation which deviates appreciably from the perpendicular to the slope if the nature of the filler material permits. In Figure 3, we see that sheet 15 of support 1 makes an angle of about 20% with respect to the vertical. As will be seen below, the orientation of the sheets 15 of the supports 1 determines the inclination of the strips fascinates 3, and for reasons of efficiency, it is obvious that the angle makes the card 15 with respect to the vertical should not be too large.

Referring to Figure 6, we see a support 1 ' according to another embodiment. In this case, the support 1 'includes a support base 10' closed by two rods 13 'forming an angle of about 90 ° between them so as to form a square. The two rods join in a point 11 'which forms the angle of the square and which serves off hook means for hanging the support 1 'to the hanging ply 2, as can be seen in the figure 7. The two free ends of the two rods 13 'are extend upwards by two 15 'plugs which make a right angle to base 10 '. So with a simple square forming the base 10 'with two 15' plugs, we obtain a support 1 'which allows a double support of the retaining element 3. In other words, there are two support points for a single attachment on the sheet. We thus doubles the carrying capacity without increasing the hooking points and without weighing down the operation of installation of the supports on the tablecloth. As we can see in Figure 7, the supports 1 'are hooked to the ply 2 at the angle 11 'of the square 10' which passes through the loop 21 of the sheet, the angle 11 'serving as hook being of course oriented towards the top of the slope. The larger the square forming the base 10 ', the greater the stability is increased and the more the cards are regularly distributed on the tablecloth. By planning by example of loops every two meters, we can get a regular distribution of cards every meter in using supports having 13 '70 square brackets cm in length.

The support 1 'shown in Figure 6 constitutes a preferred form, because it is simple to manufacture and also allows a doubling of the files for the same implementation work. However, the support of the figure 4 is also usable in certain cases. We can well heard yet imagine other forms of support fulfilling the same functions of attachment to the sheet attachment 2 and support for fascine strips 3. We can for example imagine a kind of square whose base is provided with textile attachment means 2.

The supports 1 or 1 'are arranged on the sheet attachment 2 preferably in a substantially network regular with a number of rows of support arranged substantially transversely to the slope. Number of support rows is a function of height and the inclination of the slope as well as the nature and the thickness of the filler material 4. The densities of the supports on the hanging ply 2 is also a function density and thickness of the filler material. It is the same for the height of the 15, 15 'plugs of the support 1, 1' which preferably should extend vertically over a height substantially equal to the thickness of the material input 4. Depending on all these parameters, supports specific to the type of intake chosen are hung on the attachment ply 2 according to the network defined above.

Fascinating bands 3 which may be of the same nature that the attachment ply 2, are preferably provided with hooking loops 31, as shown in FIG. 1. A instead of the hooking loops 31, it is also possible provide simple passage holes for 15, 15 'plugs support 1, 1 '. In the case of geogrids, these holes passage are formed by the mesh of the grid. Groups of fascine 3 advantageously have a width which is substantially equal to or preferably somewhat less than the thickness of the filler material 4. The different strips of fascine 3 are then mounted on the different rows parallel transverse support 1, 1 'formed by the network defined above. The mounting of fascine bands 3 is carried out by engagement of the sheets 15, 15 ′ of the supports 1, 1 'through the hooking loops 31 formed on the fascinating bands. So the fascine 3 bands are arranged transversely to the slope of the structure 5 in extending substantially perpendicular to this slope. We can also consider other configurations or arrangements of fascine bands 3, for example in rafters, if the nature of the material so requires or allows.

Thanks to the restraint system according to the invention, achieves real compartmentalisation of the filler material on the slope in rows extending transversely to this slope. This is made possible because the tapes of fascinates 3 extend over the entire thickness of the filler material. Because the hanging ply and the fascine bands exhibit characteristics of perfectly uniform resistance over the entire surface, and that the supports 1 are all identical, we obtains a finished work which shows no weakness or resistance discontinuity. In addition, since the filler material is truly compartmentalized, we avoid any risk of slipping or stalling of filler material.

The different stages will now be described. allowing the implementation of a restraint system according to the invention. The first step is to set up and to fix the hanging ply 2 on the slope of the structure 5. Then the supports 1, 1 'are put in place by hooking on the hanging ply 2. As mentioned above, their density and their height depend on the slope, the density and the thickness of the filler material. Finally, the tapes of fascinates 3 are mounted on the supports 1, 1 'so that extend transversely to the slope. Finally, the successive transverse rows are filled with filler material 4 until it comes flush with the edges upper fascine bands 3.

Instead of fascine bands, we can also use thick foam material substantially equal to that of the intake. In this case, the supports serve as holding means more than support, since the foam material stands on its own. An example of a usable foam material is shown in Figure 5.

Claims (12)

System for retaining a supply of material (4) of a certain thickness on a sloping structure (5), characterized in that it comprises: a hanging ply (2) placed flat on the sloping structure (5), support means (1; 1 ') attached to the attachment ply (2) in a network comprising at least one row arranged substantially transversely to the slope, at least one retaining element (3) supported by one, respectively several row (s) of support means and extending substantially across the entire thickness of the intake, characterized in that the support means (1; 1 ') extend substantially perpendicular to the slope over a height substantially equal to the thickness of the intake. The system of claim 1, wherein said retainers include one, respectively, several fascinated strip (s) (3) substantially supported perpendicular to the slope on one, respectively, several row (s) of support means extending substantially across the entire thickness of intake. The system of claim 1, wherein said retainers include material alveolar synthetic. System according to any of the claims previous, in which the support means (1, 1 ') include hook means (11; 11 ') for their attachment to the attachment ply (2). System according to any of the claims previous, in which the support means comprise a base (10; 10 ') resting on the attachment ply (2). The system of claims 4 and 5, wherein the base (10; 10 ') comprises the hook means (11; 11 '). System according to any of the claims previous, in which the support means (1) have at least one plug (15; 15 ') extending substantially perpendicular to the slope over a height substantially equal to the thickness of the intake. System according to any of the claims previous, in which the attachment ply (2) and the retainer (3) includes loops attachment (21, 31). The system of claims 7 and 8, wherein the plugs (15; 15 ') of the support means (1; 1') are engaged in the hooking loops (31) of the element restraint (3). System according to claims 4 and 8, in which the hook means (11; 11 ') means for support (1; 1 ') are engaged in the loops (21) of the hanging ply (2). Support means (1; 1 ') for a system for retaining a supply of material (4) of a certain thickness on a sloping structure (5), characterized in that it comprises: a lift base (10; 10 ') intended to rest on a hanging ply (2) extended on the sloping structure (5), hook means (11; 11 ') for attaching the base to the attachment ply (2), and at least one support plug (15; 15 ') extending substantially vertically from said base (10; 10') over a height substantially equal to the thickness of the intake (4) for supporting a retaining element fascinating (3). Method for implementing a system for retaining a supply of material (4) of a certain thickness on a sloping structure (5), characterized in that it comprises the following steps: installation of a hanging ply (2) on the sloping structure, attachment of support means (1; 1 ') to the attachment ply (2) in a network comprising at least one row disposed substantially transversely to the slope, which comprise a plug (15; 15') extending substantially perpendicularly to the slope over a height substantially equal to the thickness of the intake. installation of retaining elements (3) supported substantially perpendicular to the slope on the rows of support means extending substantially across the entire thickness of the intake.

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