AU2012202940B2 - A lightweight protection element and filter of the mattress type - Google Patents

Abstract

A lightweight protection element and filter of the mattress type comprises an external containment structure (10, 20), a three-dimensional internal structure (30) with a high cavity index and a granular filler material which is inserted inside the containment structure. Engagement means (50,52) of the mechanical type and distributed over the external containment structure in order to engage predetermined portions of those structures with each other.

Description

1 AUSTRALIA Patents Act 1990 OFFICINE MACCAFERRI S.P.A. COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A lightweight protection element and filter of the mattress type The following statement is a full description of this invention including the best method of performing it known to us:- IA A LIGHTWEIGHT PROTECTION ELEMENT AND FILTER OF THE MATTRESS TYPE The present invention relates to a lightweight protection element and filter of the mattress type, and in particular, though in a non-limiting manner, to a ballasted filtering 5 mattress for protecting and covering terrain, more preferably a seabed. Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, 10 integer or step, or group of elements, integers or steps. It is known from various documents, also including some from the same Applicant, to use flexible protection elements of parallelepipedal form in order to immobilize and protect, for example, underwater pipes, canal banks and beds. Those elements comprise 15 a flexible external cover which coats a gabion which is constructed from metal material and is filled with a mixture composed of bitumen, sand and stones or pebbles, so as to obtain elements having a high unit weight. Those protection elements, once made up, must be lowered into water by means of handling machines, such as cranes, mechanical arms, and the like, In order to facilitate the above-mentioned laying, operations are 20 known for producing mattress type protection elements comprising support elements which facilitate, when in use, the handling thereof. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or 25 all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application. One of the main limitations of the elements of known type is constituted by their great 30 thickness and their heaviness, which make the installation operations extremely complex and troublesome. Another limitation of the elements of known type is constituted by their limited overall dimensions, which are linked to the dimensions of the gabions and/or the forms which 35 are used for constructing them.

2 An embodiment of the present invention is to provide a protection element and filter of the mattress type which has significantly reduced weight, which allows easier installation, which has overall dimensions which are variable in accordance with the type of application necessary and which can successfully constitute protection elements 5 and a filter without longitudinal discontinuities, for example, but in a non-limiting manner, up to 200 linear metres. Another embodiment of the present invention is to provide a protection element and filter which is economical, easy and rapid to construct and which therefore allows a 10 substantial saving in terms of the time and cost of installation. In order to achieve the above-mentioned embodiments, the present invention relates to a lightweight protection element and filter of the mattress type as defined in the main claim below. 15 Summary of the Invention In one aspect of the invention there is provided a lightweight filtering mattress for protecting and covering terrains, comprising an external containment structure having 20 one or more sheets of material which define an internal space, a three-dimensional internal structure with a high cavity index comprised of non-woven geotextile disposed throughout the internal space, a granular filler material inside the three-dimensional internal structure, the granular filler material disposed to assist the three-dimensional internal structure in the filtering action and to maintain the thickness of the three 25 dimensional internal structure under load; and engagement means distributed over the external containment structure in order to engage predetermined portions of that external structure with each other. In another aspect of the invention there is provided a lightweight protection element 30 comprising: a containment structure comprising a bottom sheet and an upper portion disposed above the bottom sheet, the bottom sheet and upper portion being disposed to define a space therebetween, the bottom sheet and the upper portion being constructed from at least one of the following synthetic materials: woven geotextiles, woven geogrilles, 35 geomembranes, and geonets; a plurality of engagers each ornprising members on the bottom sheet and upper portion and engaging predetermined portions of the containment structure with each other; a three-dimensional interal structure with a high cavity index disposed 5 throughout the space in the containment stucte and comprising nonofilamns of hea-sensitve material distributed throughout the spacewihin the containment stucture wherein tihe engagerare distributed over the entire extent ofthe bottomseeet and upper portion and extend throughlhe three-dimensionalinternai structure between the bottom sheet and the upper portion so as to f same (to each other and stablze the 10 element; and graular filler matedal in the space within the conainment strucure. wherein ends of the bottom sheet and the upper option are fixed to each other so as to close thc element and retain inside it the three-dimensional structure 1 5 One of the main advantages of the present invention is constituted in that the protectin element further comprises a three-dimensional internal structure with a high cavity index, in which filler material is inserted, such as gravel silt, finely crushed stone, or any other natural granular element which is available in situ. That advantageous feature avoids the need to create internal diaphragm openings for stabilizing the miller material. According to another particularly advantageous feature, the mattress type element also comprises a double layer of geotextile material, for example, an upper layer and a lower layer, which, being connected to the three-dimensional internal structure, allow the protection element to act as a filering element and, at the same tine, to remain 25 fitted closely against the terrain to which it is applied owing to the ballast weight of the granular 1511c material.

3 Further features and advantages will be appreciated from the following description of one of the preferred embodiments, with reference to the appended drawings, given purely by way of non-limiting example, in which: - Figure 1 is a schematic perspective view of a lightweight protection element and filter of the mattress type according to the present invention; and - Figure 2 is a schematic sectioned view along line A'-A' of the element illustrated in Figure 1. With reference now to the Figures, a lightweight protection element and filter of the mattress type according to the present invention comprises an external containment structure. The external containment structure comprises a lower portion, for example, a bottom sheet 10, and an upper portion, for example, a cover sheet 20. Both the sheets 10 and 20 can be constructed from synthetic material, preferably geosynthetic material, for example, woven geotextiles or woven geogrilles, geomembranes, geonets. Alternatively, the sheets 10 and 20 can be constructed from natural material, preferably a biomat and/or a biodegradable bionet, for example, of straw, coconut fibre or wood shavings, and generally natural fibres. Preferably, a reinforcement element 48, for example, a metal net and/or a geogrille, can be engaged with the bottom sheet 10 so as to increase the resistance to traction of the whole mattress. Between the lower portion 10 and the upper portion 20, there is arranged a three-dimensional internal structure 30 with a high cavity index, preferably a non-woven goetextile, even more preferably a three-dimensional structure comprising monofilaments of heat-sensitive material, for example, synthetic polymers and/or polyamides. In accordance with a 4 particular embodiment of the present invention, the monofilaments of heat-sensitive material can be extruded onto the reinforcing metal net and/or geogrille 48. Granular filler material, for example, gravel, sand, silt, finely crushed stone or any other natural element which is preferably available in situ, is inserted inside the three dimensional internal structure 30 with a high cavity index. The granular filler material serves as an auxiliary in the filtering action of the three-dimensional draining structure 30, to maintain the thickness of the three-dimensional geosynthetic even under great loads and to weigh down the whole lightweight protection element and filter. The bottom sheet 10 and the cover sheet 20 are engaged with each other by way of engagement means, preferably of the mechanical type, for example, but in a non-limiting manner, a pair of plates 50, or continuous strips, constructed from synthetic and/or metal materials. The plates 50 are arranged, in an aligned, opposing state, on the external surfaces of the bottom sheet 10 and the cover sheet 20 and distributed over the surfaces in the region of respective openings formed in the surfaces of the two sheets 10 and 20. Each plate 50 comprises a through-hole, inside which there is passed a fixing bar 52 with a thread 54, scarfed in the plate 50 or lower strip. Two blocks 56 are screwed to the ends 54 of the bar 52 so as to secure the position of the two plates 50 along the bar 52 and to engage the bottom sheet 10 and the cover sheet 20 with each other. Naturally, a person skilled in the art could develop, without any inventive step, different engagement means, mechanical or non-mechanical, with respect to those described above without thereby departing from the scope of the present invention.

5 As is clearly visible in Figure 1, the engagement means are distributed uniformly over the entire extent of the bottom sheet 10 and cover sheet 20 so as to bring about through fastening of the protection element and filter. The ends of the sheets 10 and 20 are fixed to each other, for example, by means of continuous seams 53 so as to close the protection element and filter and retain inside it the three-dimensional structure with a high cavity index and the filler material. In accordance with another of the preferred embodiments of the present invention, the external containment structure of the protection element and filter comprises, for example, but in a non-limiting manner, a pouch or a container of synthetic or natural material, as described above, which is open at one side and inside which there is inserted the three-dimensional structure with a high cavity index and the filler material. Similarly, the open ends of the external structure are fixed to each other, for example, by means of continuous seams 53 so as to close the protection element and filter and retain inside it the three-dimensional internal structure and the filler material. In accordance with another of the embodiments of the present invention, the filler material may comprise fertile soil, seeds and/or other similar material, should the sheets 10 and 20 have been constructed from geosynthetic materials of natural fibres. The lightweight protection element and filter can thereby be used for covering terrain, embankments and inclinations which have to be renewed. The embodiments of the invention may change in accordance with the various dimensions and pieces of equipment of the finished mattresses. In particular, for finished mattresses of great linear extent, generally over from 6 to 7 metres in length, there can be used pontoons or rollers on which the elements roll, whilst for single shorter mattresses there can 6 be used lifting frames of various forms and dimensions. in that last case, the fixing bars 52 can be provided with engagement means, for example, end ring bolts, so as to be able to allow them to be connected to the lifting frame during the installation operations. Naturally, the principles of the invention remaining the same, the forms of embodiment and details of construction may vary widely with respect to those described and illustrated without thereby departing from the scope of the invention.

Claims (12)

1. A lightweight filtering mattress for protecting and covering terrains, comprising an external containment structure having one or more sheets of material which define an 5 internal space, a three-dimensional internal structure with a high cavity index comprised of non-woven geotextile disposed throughout the internal space, a granular filler material inside the three-dimensional internal structure, the granular filler material disposed to assist the three-dimensional internal structure in the filtering action and to maintain the thickness of the three-dimensional internal structure under load; 10 and engagement means distributed over the external containment structure in order to engage predetermined portions of that external structure with each other.

2. The mattress according to claim 1, wherein the external containment structure comprises a lower portion and an upper portion, the engagement means engaging the 15 lower portion with the upper portion.

3. The mattress according to claim 2, wherein the engagement means comprise mechanical engagement means. 20

4. The mattress according to claim 3, wherein the mechanical engagement means comprise at least a pair of plates, at least a fixing bar and at least a pair of blocks which can selectively be engaged with the ends of those fixing bars.

5. The mattress according to claim 4, wherein the ends of the external containment 25 structure are fixed to each other so as to close the mattress and to retain the three dimensional structure with a high cavity index and the filler material.

6. The mattress according to any one of claims 1 to 5, wherein the three-dimensional internal structure with a high cavity index comprises a non-woven goetextile and/or 30 monofilaments of heat-sensitive material. 8

7. The mattress according to claim 2, wherein the lower portion and the upper portion of the external containment structure are constructed from at least one of the following synthetic materials: woven geotextiles, woven geogrilles, geomembranes, geonets. 5

8. The mattress according to claim 2, wherein the lower portion and the upper portion of the external containment structure are constructed from at least one of the following natural materials: reed matting, biodegradable bionet, straw, coconut fibre, wood shavings. 10

9. The mattress according to any one of the preceding claims, further comprising a reinforcement element in order to increase, during use, the resistance to traction of the mattress.

10. A lightweight protection element comprising: 15 a containment structure comprising a bottom sheet and an upper portion disposed above the bottom sheet, the bottom sheet and upper portion being disposed to define a space therebetween, the bottom sheet and the upper portion being constructed from at least one of the following synthetic materials: woven geotextiles, woven geogrilles, geomembranes, and geonets; 20 a plurality of engagers each comprising members on the bottom sheet and upper portion and engaging predetermined portions of the containment structure with each other; a three-dimensional internal structure with a high cavity index disposed throughout the space in the containment structure and comprising monofilaments of 25 heat-sensitive material distributed throughout the space within the containment structure, wherein the engagers are distributed over the entire extent of the bottom sheet and upper portion and extend through the three-dimensional internal structure between the bottom sheet and the upper portion so as to fix same to each other and stabilize the element; and 30 granular filler material in the space within the containment structure, 9 wherein ends of the bottom sheet and the upper portion are fixed to each other so as to close the element and retain inside it the three-dimensional structure.

11. The element according to claim 10, wherein each engager comprises two opposing 5 plates, a fixing bar attached to the plates and having a first end and a second end, and a first block attached to the first end of the fixing bar and a second block attached to the second end of the fixing bar.

12. A lightweight filtering mattress according to claim I or a lightweight protection 10 element of claim 10 substantially as hereinbefore defined with reference to the Examples, excluding any comparative Examples.