WO2011117790A1

WO2011117790A1 - Structure for the protection and/or consolidation of slopes

Info

Publication number: WO2011117790A1
Application number: PCT/IB2011/051141
Authority: WO
Inventors: Alberto Santorum; Gabriele Santorum
Original assignee: Lasar S.R.L.
Priority date: 2010-03-26
Filing date: 2011-03-18
Publication date: 2011-09-29
Also published as: EP2575423A1; EP2575423B1

Abstract

An umbrella-shaped structure for the protection and/or consolidation of slopes comprises at least one structure (3) for holding back material and a main rod (4) connected to a central portion (5) of the structure (3) for holding back material. The structure (3) for holding back material comprises a plurality of supporting arms (2) extending from the central portion (5), and which, at least in an operating condition, extend substantially radially relative to the main rod (4), and means (8) for holding back material which are substantially flexible and are supported by the supporting arms (2). The supporting arms (2) are rotatably connected relative to the main rod (4) in such a way that they can rotate at least between a first position in which they lie in a plane transversal to the main rod (4), and a second position in which they are arranged so that they are substantially parallel with a main direction of extension of the rod, the means (8) for holding back material being coupled to the supporting arms (2) in both positions. Preferably, in the second position the supporting arms (2) are positioned adjacent to the main rod (4). There are also selective locking means (18) for, in practice, selectively preventing rotation of the arms (2) towards the second position.

Description

STRUCTURE FOR THE PROTECTION AND/OR CONSOLIDATION OF

SLOPES

* * *

DESCRIPTION

This invention relates to a structure for the protection and/or consolidation of slopes of the type normally used both as an avalanche barrier and to secure land at risk of landslides and the like.

In particular, this invention was conceived with reference to the type of protection and consolidation structures, invented by this Applicant, characterised by an umbrella shape. Such structures were initially described in patent EP 828 897. Therefore, hereinafter reference is mainly made to that type of structures.

Despite that, some aspects of this invention, described in more detail below, may apply to all types of structures comprising flexible means (such as net or the like) for holding back material which are supported at the periphery by a perimetric cord fixed to a rigid frame.

The umbrella-shaped structures comprise a mainly flat structure for holding back material at the centre of which a first end of a rigid rod is connected. The second end of the rod can be fixed to the ground. The structure for holding back material in turn comprises a plurality of arms extending radially from the central rod and means for holding back material which are supported by the arms. In general, the means for holding back material comprise a pair of superposed metal nets, one for support having large links made with thick cords, and one for actually holding back material having smaller links and made of thinner cords or the like. Each arm is also connected to the main rod by a metal tie rod.

Moreover, advantageously, the arms are hinged to the main rod, independently of each other, in such a way that they can oscillate freely (although always and only for a limited angle) to allow improved adjustment of the structure once loaded with the material to be held back. Some alternative embodiments of such a type of structures are described in patents EP 1 921 210 and EP 1 728 924. However, in said patents the arms are rigidly fixed to each other in such a way that any adjustment of the structure is inhibited. However, again in this case, in the partly assembled condition, it is possible to rotate the arms relative to each other in the plane in which they lie.

The main disadvantage of all of the prior art umbrella-shaped structures is the fact that their installation is complicated and requires relatively lengthy periods of time.

The first aspect to consider is the size of the structures which may have a surface for holding back material that measures as much as four metres by four metres, with consequent sizing of the rod and the arms, making the structure very heavy.

Second, it is important to consider that the structures usually have to be installed in inaccessible places (for example at high altitude) which cannot be reached by road. Moreover, the installation sites may be very far from the production sites.

Consequently, given the large dimensions, the structures cannot be transported assembled, which means that their assembly must be completed directly at the installation site or close to it.

At present, in most cases, the structures are sent by lorry to a base site close to the installation site where, once finished, they are picked up one by one by a helicopter and carried to the actual installation site. During transportation on the lorry, the structure for holding back material is normally separate from the central rod and, if it is too large, it is even partly disassembled to reduce its overall surface area.

Therefore, once at the base site, the structure for holding back material must first be put back together, then its main rod and tie rods must be connected. Given the dimensions and weight of the whole structure, such steps, which at first sight appear simple, prove lengthy and laborious. Moreover, to avoid assembly errors it is always necessary to have specialised personnel available at the base site.

As regards fixing of the perimetric cord to the supporting arms, at present various solutions are used, all more or less improvised.

To guarantee correct arrangement of the means for holding back material as time passes it is essential to fix the perimetric cord to the rigid frame in such a way that it cannot slide along its own extension. In the most common solutions this is done by mounting on each arm an element which together with the arm forms a slot in a plane transversal to the plane in which the cord extends. Therefore, during assembly, before being closed on itself, the cord is inserted through the various slots (one per arm). Moreover, at the same time, it must also be threaded through the links of the means for holding back material. Once it has been rigidly closed on itself, the cord is locked in position by means of clamps which interact with the slots.

However, this prior art fixing technology has several disadvantages.

In particular, said construction method is complicated because it requires cord tensioning before it can be fixed in the closed configuration. Indeed, being already inserted in the slots, to be able to fix it at the correct length, a strong pulling action must be applied to the cord.

Second, according to the prior art solutions, it is not possible to remove the cord and the means for holding back material from the supporting arms without opening and completely taking out the cord from the means for holding back material.

In this context, the technical purpose which forms the basis of this invention is to provide an umbrella-shaped structure for the protection and/or consolidation of slopes which overcomes the above-mentioned disadvantages.

In particular, the technical purpose of this invention is to provide an umbrella-shaped structure for the protection and/or consolidation of slopes which can be transported in an easier way than the prior art structures. It is also a technical purpose of this invention to provide an umbrella-shaped structure for the protection and/or consolidation of slopes which can be easily brought to its operating condition in a short period of time and without the need for specialised personnel.

In addition or as an alternative, it is also the technical purpose of this invention to provide a structure for the protection and/or consolidation of slopes which is easier to assemble than the prior art structures also as regards the means for holding back material.

The technical purpose specified and the aims indicated are substantially achieved by an umbrella-shaped structure for the protection and/or consolidation of slopes as described in the appended claims.

Further features and the advantages of this invention are more apparent in the detailed description, with reference to the accompanying drawings which illustrate several preferred, non-limiting embodiments of an umbrella- shaped structure for the protection and/or consolidation of slopes, in which:

- Figure 1 is a schematic axonometric view of a first type of structure for the protection and/or consolidation of slopes made in accordance with this invention, with the main rod pointing upwards, and with part of the hooking means removed for clarity;

- Figure 2 is a schematic side view, with some parts cut away to better illustrate others, of a detail of the structure of Figure 1 ;

- Figure 3 illustrates a second embodiment of the detail of Figure 2;

- Figures 4 and 5 illustrate a third embodiment of the detail of Figure 2;

- Figure 6 illustrates a fourth embodiment of the detail of Figure 2;

- Figure 7 illustrates a fifth embodiment of the detail of Figure 2;

- Figure 8 illustrates a sixth embodiment of the detail of Figure 2;

- Figure 9 illustrates a seventh embodiment of the detail of Figure 2;

- Figure 10 illustrates an eighth embodiment of the detail of Figure 2;

- Figure 11 illustrates a ninth embodiment of the detail of Figure 2;

- Figure 12 illustrates a second type of structure made in accordance with this invention, that is to say, a double umbrella-shaped structure which is otherwise the same as the single umbrella-shaped structure illustrated in Figure 1 ;

- Figure 13 is a schematic axonometric view of a detail of a structure made in accordance with this invention, in which a first part of the hooking means is visible; and

- Figure 14 is a schematic side view, with the cord in cross-section and other parts cut away for clarity, of a detail of a structure corresponding to that of Figure 13, with all of the parts of the hooking means visible.

The two innovative aspects of this invention are now described separately one after the other. First, the innovative aspects of the umbrella-shaped structures are described. Then, the innovative aspects relating to fixing of the means for holding back material.

With reference to the accompanying drawings, the numeral 1 denotes in its entirety an umbrella-shaped structure for the protection and/or consolidation of slopes made in accordance with this invention. It should also be noticed that for the sake of clarity, in Figures 2 to 11 only some of the arms 2 are illustrated, and that arms 2 may be shown in different positions in the same figure.

The umbrella-shaped structure 1 in its entirety is visible in Figure 1 .

In general it comprises two main parts, a structure 3 for holding back material (positioned horizontally in Figure 1 but which in practice is arranged at an angle or perpendicular to the ground) and a main rod 4 connected to a central portion 5 of the structure 3 for holding back material (the rod extending vertically in Figure 1 ). Depending on requirements, in practice, the main rod 4 may be substantially perpendicular to the plane defined by the structure 3 for holding back material, or just at an angle to it.

In the embodiment illustrated, the structure 3 for holding back material in turn comprises, first a plurality of supporting arms 2 extending from the central portion 5 and which, at least in the operating condition (such as that illustrated in Figure 1 ), extend substantially radially relative to the main rod 4. Again in the embodiment illustrated, the arms 2 are mainly girders with an '-shaped cross-section which have an inner end 6 rotatably connected to the main rod 4 and a cantilever-style free outer end 7. The method with which the arms 2 are connected to the main rod 4 is described below.

In general, there may be any number of arms 2 provided that their outer ends 7 form the corners of a polygon.

The supporting arms 2 support means 8 for holding back material which are substantially flexible, and suitable for creating in use a barrier for holding back snow, earth or the like.

In Figure 1 the means 8 for holding back material are schematically illustrated as a metal net with large links. However, according to the applications, in the known way, there may be either alternative means provided, or a second net with smaller links (metal or not) which is fixed to the metal net.

Moreover, as is schematically shown in Figure 1 , to guarantee improved support for the metal net the umbrella-shaped structure 1 also comprises an annular perimetric metal cord 9 fixed to the supporting arms 2 close to their free ends 7 and to which the metal net is fixed.

As regards the central portion 5 of the structure 3 for holding back material, in the embodiment in Figure 1 it is a tubular central body 10 in which the main rod 4 is inserted and fixed, and a plurality of fixed flanges 11 which are fixed to the central body 10 and extend radially from it. Each arm 2 is rotatably connected to one of these fixed flanges 11. However, in other embodiments, the central portion 5 of the structure 3 for holding back material may also have other forms or consist directly of the main rod 4. Preferably, there is a plurality of tie rods 12 which, at least in practice, are each connected between a supporting arm 2 of the structure 3 for holding back material 3 and the main rod 4. In the embodiment in Figure 1 , in particular, the tie rods 12 are connected to the supporting arms 2 approximately two thirds of the way along the latter. The tie rods are connected to the main rod 4 at its end opposite that connected to the structure 3 for holding back material, by means of a shaped element 13 for fixing the end of the main rod to the ground. With regard to this, it should also be noticed that although in the embodiments illustrated the main rod 4 ends at the structure 3 for holding back material, in other embodiments the main rod 4 may even extend, directly or indirectly, beyond the structure 3 for holding back material.

As already indicated, the supporting arms 2 are rotatably connected relative to the main rod 4 ("relative" to in the sense that they can be hinged directly to the main rod 4 or to another element which is fixed to it, such as the central body 10).

In particular, according to this invention, the arms 2 can rotate relative to the main rod 4 in such a way that they can rotate at least between a first position in which they lie in a plane transversal (and generally substantially perpendicular) to the main rod 4 (such as in Figure 1 ), and a second position in which they are arranged substantially parallel with a main direction of extension of the rod (as shown in Figures 3, 4, 6 to 11 ).

Advantageously, thanks to their flexibility, the means 8 for holding back material remain coupled to the supporting arms 2 in both positions (even if in the accompanying drawings they are not shown in the second position). In the case of Figures 1 to 3 and 6 to 12, when the supporting arms 2 are in the second position, the means 8 for holding back material are contained between the supporting arms 2 and the main rod 4.

In many embodiments illustrated, the supporting arms 2 as well as being able to rotate, can translate relative to the central portion 5 or to the main rod 4 in such a way that a portion 14 of them for connection to the central portion 5 or to the main rod 4 can move between a position close to the main rod 4 and a position distanced from the main rod 4. In all of the embodiments illustrated the connecting portion 14 is a pair of shaped flanges fixed to the inner end 6 of the respective supporting arm 2 (the two shaped flanges contain between them one of the radial fixed flanges 11 fixed to the central portion 5 or to the main rod 4). In all of the embodiments illustrated the connection between the various flanges is obtained by means of a pin 15 perpendicular to their main surface of extension (a pin 15 which may be fixed to the arm 2 or to the central portion 5/to the main rod 4 or to none of them, as in the case when it is a bolt or a through peg).

At least in the case of the embodiments in which the arms 2 can both rotate and translate, at least one out of the arm 2 and the central portion 5 (or the main rod 4) comprises a slot-shaped hole 16 in which in an engagement element for connection to the other part (the above-mentioned pin 15) is slidably inserted. The translation and rotation are obtained by the sliding of the engagement element in the slot-shaped hole 16 (in the case in Figures 4 and 5 both comprise slot-shaped holes 16 and the engagement element is free relative to both).

The aim of making arm 2 translation possible is to allow their rotation even in the case of dimensions which, in themselves, are such that they prevent it. Thanks to the translation, it is possible to move the point of rotation away from the main rod 4.

It should be specified that the extent of the rotation may normally range from 90° to 180°, depending on requirements.

Finally, it should be specified that the possibility of rotating the arms 2 towards the main rod 4, where provided, must be guaranteed during the step of preparing the umbrella-shaped structure 1 but must be inhibited once the structure is in operation, to prevent accidental re-closing of the umbrella-shaped structure 1 . Consequently, the umbrella-shaped structure 1 must comprise suitable selective locking means 18, described in more detail below.

However, among the various embodiments illustrated in the accompanying drawings, the preferred embodiment is that adopted in Figure 1 and illustrated in Figure 2, in which, in the second position, the supporting arms 2 are positioned adjacent to the main rod 4. The same arrangement is also provided in the embodiments in Figures 3 and 6 to 11 (as well as 12, described in more detail at the end of this text).

In contrast, regarding the embodiment illustrated in Figures 4 and 5, when the supporting arms 2 are in the second position (Figure 4), they extend, relative to the central portion 5, on the side opposite to the main rod 4. Relative to the orientation of the Figures, the main rod 4 is connected to the central portion 5 at its lower part. In this case, the central portion 5 is a horizontal plate 19 (relative to the drawings) which may be circular or square. Coupled to the two sides of the plate there are two groups of four flanges 20, 21 arranged in a cross shape (for each group two flanges are visible in side view and one in front view). The substantially triangular flanges 20 are designed for coupling to the main rod 4, whilst the substantially rectangular flanges 21 are provided with a horizontal slot- shaped hole 16 in which the engagement element slides. The engagement element is simultaneously inserted in a slot 22 made in the connecting portion 14 of the supporting arm 2. As shown in Figure 4, when the arms 2 are in the second position, the engagement element is positioned at the outer radial end of the slot 16 in the fixed flange 11 and at the inner radial end of the slot 22 made in the connecting portion 14. In contrast, when the arm 2 is in the first position, the engagement element is positioned at the opposite ends. Moreover, in this position the horizontal plate 19 forms the selective locking means 18, since it prevents rotation of the arm 2 towards the main rod 4 (advantageously there may be means not illustrated which are designed to prevent the movement of the arms 2 from the close position).

However, as already indicated, the preferred embodiment is that illustrated in Figures 1 , 2 and 12. In this case, the hinging point 23 of the arms 2 to the central portion 5 is located off centre relative to the direction of extension of the dimensions of the arm 2, on the side towards which the rotation must occur. In this way, following the rotation, the arm 2 also moves outwards to a certain extent. In this case, as in the cases in Figures 3 and 6 to 11 , the selective locking means 18 in practice selectively prevent rotation of the arms 2 towards the second position.

In particular, in this embodiment the selective locking means 18 comprise at least one removable element 24 which can be mounted between an arm 2 and the central portion 5 of the supporting umbrella-shaped structure 1 (or, in other similar solutions, the main rod 4 connected to it). The removable element 24 is advantageously a peg, appropriately comprising an enlarged head and/or split pin head, which can be inserted in two through holes 25 made respectively in the supporting arm 2 (in particular in its connecting portion 14) and in the central portion 5 (or rather in a fixed flange 11 belonging to it) - or, in other embodiments, in the main rod 4. The holes 25 are aligned when the supporting arm 2 is in the first position (right-hand part of Figure 2).

However, preferably, despite preventing the arms 2 from returning to the second position, the selective locking means 18 allow limited oscillations of the arm 2 around its first position. As shown in Figure 2, this can be achieved by shaping at least one of the holes 25 into a slot (the one in the fixed flange 11 in the accompanying drawings) in such a way as to allow oscillation when the peg is inserted in it. For that purpose the slot must extend along an arc of a circle centred at the hinging point 23.

As regards the embodiment illustrated in Figure 10, it is similar to that of Figure 2, the differences being that the hinging point 23 is not off centre but radially shifted outwards relative to the main rod 4 (not illustrated), and that the peg is inserted in two circular holes which prevent any oscillation.

In the case of the embodiments in Figures 3 and 6 to 9, the arms 2 are able to rotate and translate according to the methods described above, and the selective locking means 18 comprise, for each supporting arm 2, at least one contact element 26, fixed relative to the main rod 4, against which the arm 2 interacts if, when it is simultaneously in the first position and in the close position, it is pushed to rotate towards the second position. In contrast, the fixed contact element 26 does not prevent oscillations of the supporting arms 2 beyond the first position. Such oscillations are limited by the tie rods 12. The movement of the arms 2 from the close position to the distanced position causes disengagement of the selective locking means 18.

In the case in Figure 11 , the rotation is similar to that of Figures 3 and 6 to 9, whilst the selective locking means 18 comprise at least one removable collar 27 which can be removably mounted on the main rod 4 at the central portion 5. The collar 27 may be open or openable in such a way that it can be mounted on the rod radially, or closed. In this latter case, it must be able to slide along the rod in such a way that it can be moved from a position beyond the zone affected by the supporting arms 2 located in the second position, to a position close to the central portion 5. There will also be suitable means, not illustrated, provided for keeping the collar in the latter position with the umbrella-shaped structure 1 in the operating condition. Finally, Figure 12 shows a double umbrella-shaped structure 1.

In this case, the umbrella-shaped structure 1 also comprises a second structure 3 for holding back material, with respective tie rods 12, substantially mirroring the first and fixed to the opposite end of the main rod 4. The distance between the two umbrella-shaped structures is not less than twice the length of the arms 2, in such a way that all of the arms 2 can be simultaneously brought into the second position. Moreover, in this case, the tie rods 12 of each structure 3 for holding back material are fixed to an intermediate portion of the main rod 4. However, in other embodiments, the tie rods 12 may even be fixed to any other portion of the main rod 4, for example to its ends.

As regards operation of the umbrella-shaped structures according to this invention, in practice, they have the supporting arms 2 arranged in the first position and behave exactly like the prior art structures. However, they differ from the prior art structures during the set-up and transportation step.

The umbrella-shaped structures may be completely, or almost completely, assembled directly at the production site. In particular, they may be completely assembled when the selective locking means 18 are fixed to one of their parts (Figures 3, 6 to 9), the locking depending exclusively on the position of the arms 2, whilst they may be almost completely assembled when the selective locking means 18 comprise removable parts (removable element 24 as in Figures 1 , 2, 10 and 12, or removable collar 27) which must be mounted only during the step of opening the umbrella-shaped structure 1. In contrast, in the case of embodiments similar to those illustrated in Figures 4 and 5, it is definitive fixing of the tie-rods 12 which must be delayed.

In accordance with this invention, once the set-up has been completed, or almost completed, the arms 2 can be moved to the second position with the means 8 for holding back material fixed to them, transforming a very large umbrella-shaped structure 1 into an elongate object with limited cross- section. Therefore, the umbrella-shaped structures can easily be packaged and transported to the base site (a single lorry can transport a large quantity of them).

Having reached the site, they can simply be unpacked, the arms 2 opened and fixed in the first position, and the umbrella-shaped structures are ready. At that point they can be picked up (for example by a helicopter) and carried to the installation point.

As already indicated, a second innovative aspect of this invention relates to the method for assembly of the means 8 for holding back material. Hereinafter that aspect is described mainly with reference to an umbrella- shaped structure 1 of the type described above (single, as in Figure 1 , or double, as in Figure 12). Despite that, it shall be considered applicable to any type of structure 1 for the protection and/or consolidation of slopes in which the means 8 for holding back material are substantially flexible and supported at the periphery by a supporting cord 9.

Therefore, in general, this aspect of this invention is applied to structures 1 for the protection and/or consolidation of slopes which comprise at least one structure 3 for holding back material which in practice extends mainly flat, and which in turn comprises a plurality of rigid supporting elements 28, at least one perimetric cord 9 fixed to at least one of the rigid supporting elements 28 by means of hooking means 29, and means 8 for holding back material which are substantially flexible and are supported by the perimetric cord 9 and, directly or indirectly, by the rigid supporting elements 28 for in practice creating a barrier for holding back snow, earth or the like. The perimetric cord 9 also extends along a closed trajectory which is generally polygonal.

In the case in which the structure is an umbrella-shaped structure 1 , as seen, it also comprises a main rod 4 connected to a central portion of the structure 3 for holding back material transversally to its main plane of extension. The structure 3 for holding back material in turn comprises a plurality of arms forming the rigid elements 28 (and which therefore hereinafter are labelled with the same reference number 2), extending substantially radially from the central portion 5 and which are also connected to the main rod 4 by means of a plurality of tie-rods 12. According to requirements, in practice, the arms 2 may be rigidly fixed both to the main rod 4 and to each other, or they may be free to oscillate relative to each other and/or relative to the main rod 4 (as described above). However, advantageously, to take full advantage of the potential of this invention, preferably at least in a semi-assembled condition, the supporting arms 2 should be able to move relative to each other and/or relative to the axis in such a way as to reduce the length of the path passing through the points for constraining the cord 9 to the arms 2, relative to the operating condition. This point is also referred to below.

As already indicated, the umbrella-shaped structure 1 may be a single structure (as shown in Figure 1 ) or double (as shown in Figure 12). In the latter case, in a known way, the only difference is generally the presence of a second structure 3 for holding back material, which substantially mirrors the first and is positioned at the opposite end of the main rod 4.

In accordance with this invention, in the most simple embodiment, the means 29 for hooking the cord 9 to a rigid element 28 comprise a pair of shaped elements 30 and a clamping element 31 (only illustrated in Figure

14).

The shaped elements 30 are fixed to the rigid supporting element 28 in such a way that each forms, in a plane substantially perpendicular to the main plane of extension of the structure 3 for holding back material (that is to say, in the plane of the drawing of Figure 14), a recess 32 facing outwards relative to the closed path identified by the extension trajectory of the perimetric cord 9. As shown in Figures 13 and 14, the perimetric cord 9 is { transversally inserted in said recess 32.

In contrast, the clamping element 31 is rigidly clamped on the perimetric cord 9 and is positioned between the shaped elements 30 (Figure 14 shows in the foreground a shaped element 30 and behind it the clamping element

31. The other shaped element 30 is further back, behind the clamping element 31 ). In addition, the clamping element 31 has an extension, transversally to the cord 9 (that is to say, parallel with the plane of the drawing of Figure 14), greater than the size of the recess 32, thus preventing movements of the cord 9 along its own extension (perpendicular to the plane of the drawing of Figure 14) beyond the shaped elements 30

(thanks to the interference of the clamping element 31 against the shaped elements 30).

Advantageously, the distance between the shaped elements 30 is slightly greater than the width of the clamping element 31 substantially for preventing significant movements of the cord 9 both ways along its own direction of extension.

As shown in Figure 13, the shaped elements 30 extend cantilever-style from the rigid element 28, along a trajectory which lies in a plane substantially perpendicular to the main plane of extension of the structure 3 for holding back material and which is angled towards the outside of the closed trajectory defined by the cord 9. In particular, in the preferred embodiments this is achieved thanks to the fact that the shaped elements 30 are substantially "C"-shaped, with one side of the "C" directly associated with the rigid element 28 (for example by welding).

However, in the most complete embodiment of this invention, the hooking means 29 also comprise at least one closing element 33 mounted between the shaped elements 30 for preventing the clamping element 31 from shifting outwards relative to the closed trajectory defined by the cord 9. The closing element 33 may be of any type, provided that it can constitute an obstacle to the cord 9 exiting the recesses once the clamping element 31 has been mounted on it.

Consequently, the closing element 33 may be fixed either to one of the shaped elements 30 or to the rigid element 28.

However, in the preferred embodiment, the closing element 33 connects the cantilever-style free ends of the shaped elements 30. More particularly, as Figure 13 clearly shows, the shaped elements 30 and the closing element 33 are made from a single piece of shaped material (overall having the shape of a hook). In this way, shifting of the cord 9 out of the recess 32 according to the arrow in Figure 14 is impossible, since the clamping element 31 remains locked between the closing element 33 and the rigid arm 2.

With reference to the clamping element 31 , in particular in the most complete embodiment, it is advantageously an openable clamp comprising a "U"-shaped element 34 with threaded ends, a bar 35 with two through holes in it, through which the ends of the "U"-shaped element 34 are inserted and two locknuts 36 which are screwed onto the threaded ends. More particularly, the "U"-shaped element 34 is sized in such a way that it does not interfere with the closing element 33, whilst the bar 35 has greater dimensions, such that it does interfere. In this way, the clamping element 31 is easily mounted even when the cord 9 is already inserted in the recesses. The "U"-shaped element 34 can simply be inserted on the cord 9 from the outside to the inside of the closed trajectory, and locked with the bar 35 and the two nuts 36.

Moreover, advantageously, the structure comprises a plurality of hooking means 29 of the type described above, which are distributed along the entire extension of the cord 9.

In the case illustrated, in particular, the cord 9 extends along a polygonal trajectory substantially passing at the outer ends of the supporting arms 2 and the hooking means 29 are positioned at least at one of the vertices of the polygon, advantageously at all of them.

In the case of application of fixing of the means for holding back material in accordance with this invention, operation of the structures is obviously the same as that of prior art structures. What changes is the assembly method, in particular in the case in which the rigid elements 28 can move according to the methods indicated above (reduction of the path for the cord 9). In the case of umbrella-shaped structures 1 of the type illustrated, this may be achieved either by rotating all of the arms 2 in the plane defined by the arm 2 itself and by the main rod 4 in such a way as to bring the outer ends of the arms towards the main rod 4, or by rotating one or more of the arms 2 in the plane in which they lie (if the supporting arms 2 are arranged in a cross shape, varying the angle changes the length of the rectangle which inscribes it).

In this case, the cord 9 may be closed on itself at the correct length with the means 8 for holding back material already fixed to it, before being installed on the rigid elements 28. For subsequent installation, the arms 2 simply have to be brought to the rotated configuration, the cord 9 inserted in the recesses and the arms 2 returned to the operating position, thus tensioning the cord 9. At that point, the clamping elements can be fixed, so that any further movement of the arms 2 can no longer cause any shifting of the cord 9 and of the means 8 for holding back material from the correct position. This invention therefore brings important advantages.

First, the umbrella-shaped structures according to this invention may be transported much more easily than the prior art umbrella-shaped structures. Second, thanks to the fact that they are completely or almost completely assembled at the production site, the times needed to bring them to the operating condition at the base site can be minimised. Moreover, there is no need for specialised personnel, since completing assembly may require at most the fixing of several movable pieces.

As regards the method for fixing the perimetric cord to the supporting arms, this invention allows the structures to be assembled in a way that is much simpler than for conventional solutions. It also allows, in a quite simple way, any necessary separation of the cord and the means for holding back material from the rigid elements without requiring their disassembly.

Finally, it should be noticed that this invention is relatively easy to produce and that even the cost linked to implementing the invention is not very high. The invention described above may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted with other technically equivalent elements and the materials used, as well as the shapes and dimensions of the various components, may vary according to requirements.

Claims

1. An umbrella-shaped structure for the protection and/or consolidation of slopes comprising:

at least one structure (3) for holding back material;

a main rod (4) connected to a central portion (5) of the structure (3) for holding back material;

the structure (3) for holding back material in turn comprising a plurality of supporting arms (2) which extend from the central portion (5), are rotatable relative to the main rod (4) and which, at least in the operating condition, extend substantially radially relative to the main rod (4), and means (8) for holding back material, these means being substantially flexible, supported by the supporting arms (2), and suitable for creating in use a barrier for holding back snow, earth or the like;

characterised in that the supporting arms (2) are rotatably connected relative to the main rod (4) in such a way that they can rotate at least between a first position in which they lie in a plane transversal to the main rod (4), and a second position in which they are arranged so that they are substantially parallel with a main direction of extension of the rod, the means (8) for holding back material being coupled to the supporting arms (2) in both positions.

2. The umbrella-shaped structure according to claim 1 , characterised in that in the second position the supporting arms (2) are positioned adjacent to the main rod (4).

3. The umbrella-shaped structure according to claim 2, characterised in that it also comprises selective locking means (18) for selectively preventing, during operation, rotation of the arms (2) towards the second position.

4. The umbrella-shaped structure according to claim 3, characterised in that the selective locking means (18) comprise at least one removable element (24) which can be mounted between an arm (2) and the central portion (5) of the structure (3) for holding back material or the main rod (4) connected to it.

5. The umbrella-shaped structure according to claim 4, characterised in that the removable element (24) is a peg which can be inserted in two through-holes (25) made respectively in the supporting arm (2) and in the central portion (5) or in the main rod (4), the holes being aligned when the supporting arm (2) is in the first position.

6. The umbrella-shaped structure according to any of the claims from 3 to 5, characterised in that the selective locking means (18) also allow limited oscillations of the arm (2) around its first position.

7. The umbrella-shaped structure according to claims 5 and 6, characterised in that at least one of the holes is slot-shaped, allowing said oscillation when the peg is inserted in it.

8. The umbrella-shaped structure according to any of the foregoing claims, characterised in that the supporting arms (2) are also able to translate relative to the central portion (5) or to the main rod (4) in such a way that their portion (14) for connection to the central portion (5) or to the main rod (4) can move between a position close to the main rod (4) and a position distanced from the main rod (4).

9. The umbrella-shaped structure according to claim 8, characterised in that for each arm (2), the arm (2) itself and/or the central portion (5) or the main rod (4) comprise a slot-shaped hole (16) and also being characterised in that there is an engagement element connected to the other part and slidably inserted in the slot-shaped hole (16), said translation and rotation of the arms (2) being obtained through sliding of the engagement element in the slot-shaped hole (16).

10. The umbrella-shaped structure according to claims 3 and either 8 or 9, characterised in that the selective locking means (18) comprise, for each supporting arm (2), at least one contact element (26) which is fixed relative to the main rod (4), against which the arm (2) interacts if, when it is simultaneously in the first position and in the close position, it is pushed to rotate towards the second position.

11. The umbrella-shaped structure according to any of the foregoing claims, characterised in that the selective locking means (18) comprise at least one removable collar (27) which is open, openable or closed and can be mounted around the main rod (4) at the central portion (5) for locking the supporting arms (2).

12. The umbrella-shaped structure according to claim 1 , characterised in that in the second position the supporting arms (2) extend, relative to the central portion (5), on the side opposite to the main rod (4).

13. The umbrella-shaped structure according to any of the foregoing claims, characterised in that it also comprises a plurality of tie rods (12) which, at least in practice, are each connected between one of the supporting arms (2) and the main rod (4).

14. The umbrella-shaped structure according to any of the foregoing claims, characterised in that it also comprises a second structure (3) for holding back material which substantially mirrors the first and is fixed to the main rod (4) at a predetermined distance from the first structure (3) for holding back material.

15. The structure for the protection and/or consolidation of slopes according to any of the foregoing claims, wherein the structure (3) for holding back material also comprises at least one perimetric cord (9) fixed at least to one of the supporting arms (2) by means of hooking means (29), the perimetric cord (9) extending along a closed trajectory, the means (8) for holding back material also being supported by the perimetric cord (9), and wherein the hooking means (29) comprise:

a pair of shaped elements (30) which are fixed to a supporting arm (2) in such a way that, in a plane substantially perpendicular to the main plane of extension of the structure (3) for holding back material, each forms a recess (32) facing towards the outside of the perimetric cord (9) trajectory, the perimetric cord (9) being transversally inserted in the recess (32); and a clamping element (31 ) which is clamped on the perimetric cord (9) and positioned between the shaped elements (30), the clamping element (31 ) having an extension, transversally to the cord (9), which is greater than the size of the recess (32);

the distance between the shaped elements (30) being slightly greater than the width of the clamping element (31 ) for substantially preventing significant movements of the cord (9) along its extension thanks to interference of the clamping element (31 ) with the shaped elements (30).

16. The structure according to claim 15, characterised in that the shaped elements (30) extend cantilever-style from the arm (2) along a trajectory lying in a plane which is substantially perpendicular to the main plane of extension of the structure (3) for holding back material and which is angled towards the outside of the closed trajectory defined by the cord (9).

17. The structure according to claim 16, characterised in that the shaped elements (30) are substantially "C"-shaped with one side of the "C" directly associated with the arm (2).

18. The structure according to any of the claims from 15 to 17, characterised in that the hooking means (29) also comprise at least one closing element (33) which is mounted between the shaped elements (30) to prevent shifting of the clamping element (31 ) outwards relative to the closed trajectory defined by the cord (9).

19. The structure according to claims 16 and 18, characterised in that the closing element (33) connects the cantilever-style free ends of the shaped elements (30).

20. The structure according to claim 18 or 19, characterised in that the shaped elements (30) and the closing element (33) consist of a single shaped piece.

21. The structure according to any of the claims from 15 to 20, characterised in that the clamping element (31 ) is an openable clamp.

22. The structure according to any of the claims from 15 to 21 , characterised in that it comprises a plurality of the hooking means (29) distributed along the extension of the cord (9).

23. The structure according to any of the claims from 15 to 22, characterised in that the cord (9) extends along a polygonal trajectory, the hooking means (29) being positioned at least at one of the vertices of the polygon.

24. A structure for the protection and/or consolidation of slopes comprising at least one structure (3) for holding back material which extends mainly flat, in turn comprising

a plurality of rigid supporting elements (28);

at least one perimetric cord (9) fixed to at least one of the rigid supporting elements (28) by hooking means (29), the perimetric cord (9) extending along a closed trajectory; and

means (8) for holding back material which are substantially flexible and supported by the perimetric cord (9) and by the rigid supporting elements (28) so that in practice they create a barrier for holding back snow, earth or the like;

characterised in that the hooking means (29) comprise:

a pair of shaped elements (30) which are fixed to a rigid supporting element (28) in such a way that, in a plane substantially perpendicular to the main plane of extension of the structure (3) for holding back material, each forms a recess (32) facing towards the outside of the perimetric cord (9) trajectory, the perimetric cord (9) being transversally inserted in the recess (32); and

a clamping element (31 ) which is clamped on the perimetric cord (9) and positioned between the shaped elements (30), the clamping element (31 ) having an extension, transversally to the cord (9), which is greater than the size of the recess (32);

25. The structure according to claim 24, characterised in that the shaped elements (30) extend cantilever-style from the rigid element (28) along a trajectory lying in a plane which is substantially perpendicular to the main plane of extension of the structure (3) for holding back material and which is angled towards the outside of the closed trajectory defined by the cord (9).

26. The structure according to claim 25, characterised in that the shaped elements (30) are substantially "C"-shaped with one side of the "C" directly associated with the rigid element (28).

27. The structure according to any of the claims from 24 to 26, characterised in that the hooking means (29) also comprise at least one closing element (33) which is mounted between the shaped elements (30) to prevent shifting of the clamping element (31 ) outwards relative to the closed trajectory defined by the cord (9).

28. The structure according to claims 25 and 27, characterised in that the closing element (33) connects the cantilever-style free ends of the shaped elements (30).

29. The structure according to claim 27 or 28, characterised in that the shaped elements (30) and the closing element (33) consist of a single shaped piece.

30. The structure according to any of the claims from 23 to 29, characterised in that the clamping element (31 ) is an openable clamp.

31. The structure according to any of the claims from 23 to 30, characterised in that it comprises a plurality of the hooking means (29) distributed along the extension of the cord (9).

32. The structure according to any of the claims from 23 to 31 , characterised in that the cord (9) extends along a polygonal trajectory, the hooking means (29) being positioned at least at one of the vertices of the polygon.

33. The structure according to any of the foregoing claims, characterised in that it is a single or double umbrella-shaped structure (1 ), and it also comprises a main rod (4) connected to a central portion (5) of the structure (3) for holding back material transversally to its main plane of extension, and also being characterised in that the structure (3) for holding back material comprises a plurality of arms (2) forming the rigid elements (28) and extending substantially radially from the central portion (5).