WO2022023606A1

WO2022023606A1 - Tool and method for the decompaction of the surface of slopes

Info

Publication number: WO2022023606A1
Application number: PCT/ES2021/070551
Authority: WO
Inventors: Saturnino de Alba Alonso; Jose Francisco MARTIN DUQUE; Ignacio Mola Caballero de Rodas
Original assignee: Universidad Complutense De Madrid
Priority date: 2020-07-31
Filing date: 2021-07-22
Publication date: 2022-02-03
Also published as: WO2022023606A8

Abstract

A tool and method for the decompaction of the surface of slopes. The present invention relates to a tool for preparing the soil during the completion stage of the construction of slopes and other slope maintenance operations, particularly that of aiding revegetation and reducing erosion. The tool presents a roller (1) into which diametrically symmetric rods (8) are inserted, forming pairs of spikes (2), asymmetric diametrical rods (7) or radial rods (6) that generate spikes (2) that project from the surface of the roller (1). The roller is inserted into a fork (4) by means of bearings (3) that enable it to rotate freely, with no need for mechanical traction and elements for the coupling thereof to the articulated arm of a civil works or agricultural machine. The invention likewise relates to a method for preparing or maintaining the surface of slopes that includes the use of the tool of the invention.

Description

IMPLEMENT AND METHOD FOR DECOMPACTING THE SURFACE OF

SLOPES

TECHNICAL SECTOR

The present invention falls within the field of devices for treating the surface of the earth. More specifically, it refers to devices for preparing the soil during the finishing phase in the construction of slopes and for other slope maintenance operations, especially to promote revegetation and reduce erosion.

BACKGROUND OF THE INVENTION

The construction of a linear infrastructure —such as a highway or a railway—, the operations of a mining exploitation or other activities that involve earthworks, generate severe alterations in the environmental conditions of the space in which they are developed. These modifications cause the destruction of the soil as a structured and functional system (in the edaphological sense), capable of hosting different and diverse biological communities, among which the plant cover stands out, which is also eliminated. For the successful ecological restoration of these new spaces, it is essential that the new exposed surface be capable of housing biological communities (vegetation cover included), so that surface runoff and its erosive effect are properly managed (Forman et al. 2002 -Road Ecology Science and Solutions, Island Press, Washington DC 481 pp. 171-199).

In Spain, regarding the construction process of new surfaces (clearings, embankments and esplanades), the general technical specifications for both roads (General technical specifications for road and bridge works (PG-3), in force on June 1 of 2019, of the Secretary of State for

Infrastructures, Transport and Housing, of the Ministry of Public Works) and railways (General specification of standard technical specifications for platform projects, PGP-2011, June 2011 edition, ADIF) specify the activities or work units that make up the construction of a linear infrastructure, as well as the way to verify its execution (measurement and payment).

Both specifications face the description of the construction units separating excavations and drainages. It is assumed that the runoff produced in the slope plane is handled by external drainage elements (ditches, downspouts, etc.). No section mentions how to manage runoff within the slope. On the contrary, in the sections that identify the finishing works of the slopes (refining of slopes) it is indicated textually: “it consists of the operations necessary to achieve the geometric finish” . That is to say, the concern at this point is purely morphological, directed by the operability of the machinery and the final aesthetic, and under a framework of non-natural geometries. It is indicated that these works will be carried out after the construction of drains and other works. In particular, emphasis is placed on "removing any soft, unsuitable or unstable material that cannot be adequately compacted, as well as filling voids". Reference is also made to how to proceed in the event of a landslide (filling and returning to the initial situation.) Therefore, it is assumed that the drainage systems are adequately sized to capture and channel both the runoff generated on the slope and the erosion and emission of sediments.

On the other hand, in those specific spaces in which, due to their singularity, the occurrence of landslides, erosive phenomena or deposition of materials cannot be assumed, due to the serious risk that it would pose to the safety of people (for example at the mouth of tunnels , as well as other specific points of the infrastructure), special slope protection treatments are carried out, normally using techniques based on containment. That is, acting on the negative effects of the process, and not reversing its causes. Among these treatments we can highlight: shotcrete (projecting concrete on the surface of the slope), bolts and deep type drainage (carried out perpendicular to the surface of the slope and towards the interior of the land), metallic meshes, geotextiles, three-dimensional meshes, geocells (different techniques that completely cover the surface of the slope), among others. All these techniques, as has been indicated, are applied in a punctual and extraordinary way, given the enormous cost that their application entails.

In the field of slope treatment, and as a preventive measure, frequently steel wire meshes that are deployed from the upper part of the slope, so that they guide the small landslides towards the ditches or catchment areas on the sides of the road or area to be protected. This type of mesh is also used in flexible slope stabilization and protection systems, combined with anchoring systems to the stable area of the ground. There are also a large number of variations when preparing slope protection meshes, depending on the type of terrain. For example, patent EP2264247B1 describes a network, and the process for making it, for use as a geogrid in geotechnical applications. Patent ES2690731T3 protects a seamless geotextile network with a cellular structure for soil stabilization that can be used to reinforce slopes, embankment cones, retaining walls in constructions for transportation or hydraulic engineering, among others. Document ES1071411 U proposes a protective covering for land comprising a layer of weft and warp fabric intended to be spread and fixed on the land to be protected and tubular wefts of natural fibers that contain seeds. The procedure is specially designed for arid and uncultivated land (devoid of plant cover), such as slopes, embankments, clearings, dunes or areas adjacent to infrastructures, affected by works; all this to protect them from erosion and facilitate the growth of a plant cover.

Finally, once the new surfaces are finished, revegetation techniques are developed with two fundamental objectives: to produce landscape integration and minimize erosion. These techniques are mainly based on amendments to try to remedy the lack of soil (extensions of topsoil or fertile substrate, contributions of organic matter, nutrients, etc.) and introduce propagules (seeds) or individuals (plantations) of different plant species, to form a vegetative cover. If there is intense water erosion, the plant cover cannot be installed, due to the loss of soil, water available for plants, nutrients and seeds, and due to soil compaction, either due to loss of disaggregated surface material, or due to its 'sealed'. Vegetative cover can attenuate erosion, but if there is intense erosion, it cannot develop, a dilemma that the usual revegetation techniques are not capable of adequately solving. Increasing the quality of the microsite, and therefore its capacity to host biological communities, is revealed as a successful way to promote more efficient revegetation (Mola, I., Jiménez, MD, López-Jiménez, N., Casado, MA, Balaguer L. 2011. broadside claim outside the revegetation season: Management options under schedule pressure. Restoration Ecology 19: 83-92).

The contents of the aforementioned specifications, although they are Spanish national documents, do not differ much from those that can be found in similar documents of other nationalities as regards the specific aspect of erosion control within the slope plane. . For example, in countries like Australia, where there are certified technicians in erosion control and where the approval of the works plan is necessary, they also do not have specific measures for the treatment or finishing of the slope surface. But they are very demanding with the rapid revegetation of the slope, up to coverages greater than 50%. In the event that the rainy season arrives, and if the slope does not have significant vegetation cover, there may be an obligation to cover it entirely with blankets and/or meshes that prevent erosion. Erosion control, in this case, presents an approach very marked by bioengineering (mesh, nets, hydromulching, etc.).

At an international level, the use of soil erosion models (USLE type, Universal Soil Loss Equation, that is, Universal Soil Loss Equation) applied to slopes of linear infrastructures has been very common. With them, the objective has been to evaluate their erosion rates, which, if high, were addressed through revegetation. For example, Meyer and Rómkens (Meyer, LD, Rómkens, JM 1976. Erosion and sediment control on reshaped ¡and. In: Proceedings, Third Interagency Sediment Conference, PB-245-100, 2-75, 2-76, Water Resources Council, Washington DC), after applying the USLE, they propose the use of mulching techniques, revegetation, construction of sedimentation ponds and modification of the general topography of the slope (concave, convex...) to reduce water erosion . Seutloali and Beckedahl (Seutloali, KE, Beckedahl, HR 2015. A Review Of Road-Related Soil Erosion: An Assessment Of Causes, Evaluation Techniques And Available Control Measures. Earth Sci. Res. J. vol.19 no.1) perform a synthesis of the methods used to control erosion on road embankments, and conclude that vegetation has been and is the most widely used measure at the international level.

On the other hand, the emission of sediments, especially intense in the first rain events after the construction of slopes, causes the drainage systems to collapse with the deposition of eroded materials (ditches underground, clogged drains, etc.). In the case of linear land transport infrastructures, this effect is especially important, given that the space must allow the infrastructure to operate, and the collapse of the drainage systems can cause flooding and other incidents that undermine its functionality (cuts of traffic or decrease in capacity) and the corresponding associated costs. To these economic items should be added the maintenance costs (cleaning gutters, unblocking drains, manholes and other drainage elements) which can also be very high. In Mediterranean environments, in particular, around €3,000 per linear kilometer have been established for state-of-the-art motorways during the first 5-10 years after their construction.

In short, the conventional procedures currently applied for the finishing and maintenance of artificial slopes have been shown to be ineffective in controlling the surface erosion processes that develop on them and, therefore, in minimizing the set of negative effects caused by water erosion. the slope surface.

EXPLANATION OF THE INVENTION

Tool and method for decompacting the surface of slopes.

To promote soil stability against water erosion and facilitate revegetation processes, an implement is presented to perform mechanical decompacting operations on the slope surface. The implement is designed to be installed on standard models of conventional civil engineering machinery, only needing to adapt the connection bracket in each case.

In this descriptive report, we understand slopes to be inclined planes generated artificially by activities that involve earthworks (Civil Works, Building, Mining, etc.). These can be by excavation, called clearing, or by accumulation and compaction of materials, called embankments.

One aspect of the present invention relates to an implement that includes a roller arranged as a central axis, from which a series of spikes or needles radiate out. Each pair of tines is built from a diametral bar that crosses the central axis of rotation and protrudes on both sides of it, forming two opposite tines that are equal in length, which is why we call it a symmetrical diametral bar. Alternatively, each tine may be made up of a radial bar which is inserted into the roller long enough to be securely fastened. In this specification, the part of the diametral bar or the radial bar that protrudes from the roller is called a spike. The spikes protrude from the surface of the roller perpendicular to its diameter and are distributed around the roller in such a way that when rolling on the ground they produce a spatial pattern of impacts on the surface of the ground, as irregular and random as possible. In the surface of the roller, holes are made through which the radial bars or the symmetrical diametral bars are inserted. In this second case, the symmetrical diametral bars traverse the roller diametrically, generating two tines, one tine on each side of the roller. The arrangement of the radial bars and the symmetrical diametral bars can be totally random or it can follow some pattern. For example, using symmetrical diametral bars and taking as reference the circumference that delimits the surface of the roller, the tines can protrude every 45°, that is, being 0 ^o the vertical, a symmetrical diametral bar would be inserted at 0 ^o , another at 45 °, another at 90° and another at 135°, which would generate spikes at 0 ^o , 45°, 90°, 135°, 180°, 225°, 270° and 315°, preferably avoiding repeating the same angle in consecutive spikes.

The present invention includes the necessary means and elements to keep the bars that form the pins held in position. For example, in the case of symmetrical diametral bars, they can have two holes, arranged on each side of the external diameter of the roller, next to the surface of the same, to insert pins or bolts with which to fasten the bar to the roller. In the case of radial bars, other fastening elements to the roller can be used, such as threads. An intermediate option is the asymmetrical diametrical bars that, on the one hand, protrude from the roller, forming the corresponding prong _T and, on the opposite end, have the necessary length to be able to fasten them to the roller, by means of suitable elements. For example, holes can be made that are located next to the surface of the roller, in which pins or bolts will be inserted. Another option is to generate a thickening of the asymmetrical bar material at the end that does not generate a barb, thickening of the type of the bolt heads or type thumbtack, which acts as a stop, and, at the opposite end, fasten the asymmetrical diametral bar using the necessary holes and pins.

In this way, the bars can be removed in case the tines need to be replaced, either due to deterioration or to change them for others of a different length. The pins preferably have a length of between 20 and 45 cm and a diameter of between 20 and 35 mm. The end of each pick is carved in the shape of a chisel with a flat, conical or pyramidal tip, which can be between 2 and 3 cm long.

Along the length of the roller, the number of holes made to insert radial bars, symmetrical diametrical bars, or asymmetrical diametrical bars can be variable. They can be practiced, for example, every 50, 100, 120 mm or at any other distance. In the case of radial bars, several bars can be inserted at the same distance from one of the ends of the roller, but at angular distances between 90° and 270°. In addition, when preparing the implement for use, radial bars, symmetrical diameter bars or asymmetrical diameter bars can be included in all the holes present in the roller, or a certain number and distribution of bars can be selected to give rise to to the desired tine pattern.

Preferably, the roller is made of hardened metals or metal alloys (including steel), with a diameter between 100 and 200 mm and a length of up to 2 m. The bars that form the spikes are also preferably made of metal or metal alloys, forming resistant structures.

The implement also includes the necessary elements to be able to attach it to an articulated arm of civil works machinery such as a backhoe or Pathfinder articulated hydraulic crane, or to agricultural machinery. Preferably, these elements refer to a Y-shaped fork in which the roller axis is installed in two bearings, installed in the lateral arms of the fork, in such a way that the implement can rotate freely, without any mechanical traction. The Y of the fork can take various shapes: hemioctagonal, hemirectangular, semicircular or any shape that provides two support points for the roller and allows it to rotate freely. The implement allows for decompacting the soil or substrate, spatially distributed in a non-continuous way (in a mosaic) on the surface of the space to be treated. Due to the steep slopes that can result from creating new ground surfaces due to human activities, generally greater than 30°, it could be thought that a decompaction treatment applied continuously over the entire surface of the slope could cause a critical increase in its instability, due to the loss of cohesion in the surface layer of the soil. However, the punctual and mosaic decompaction treatment achieved with the use of this tool increases the stability of the slope as its physical heterogeneity increases.

Another aspect of the invention relates to a method of decompacting the surface of a slope that includes making punctual, isolated breaks in the surface crust of the soil, creating micro-depressions characterized by having a small central hole, with an ovoid plane and lateral slightly raised, as 'microcraters', affecting a variable surface of between 25 and 50 cm ² . These punctual ruptures of the surface crust of the soil are distributed spatially on the plane of the slope, in an isolated and discontinuous way, and in the form of a mosaic.

To carry out punctual and discontinuous breakages of the ground surface, one aspect of the invention refers to the method of decompacting the surface of a slope that includes the use of an implement such as the one described in this specification, coupled to the arm articulated from a civil works machine such as a Palfinger backhoe or articulated hydraulic crane, or to agricultural machinery, rolling it on the surface of the slope so that the tines dig into the surface of the slope to an average depth of 5 to 10 cm .

This method is preferably indicated for lithological substrates that, although they may be slightly consolidated or cemented, are not hard rocks. Examples of substrates for which it is indicated are: gravel, sand, silt and slightly consolidated or cemented clay; arkose; shales; plasters; loams; different types of slope debris; regoliths and soils (edaphic) of all kinds. Examples of rocky substrates for which it is not indicated are: all types of igneous and metamorphic rocks that are not weathered (for example: basalts, granites, gneisses, schists, slates or quartzites) and highly lithified sedimentary rocks (limestone or dolomites, among others).

In turn, this treatment has effects on the physical fertility of the slope, which include: a) the breaking of the superficial crust of the soil, which increases permeability and infiltration, and with it the availability of water for plants; b) the creation of a mosaic of runoff ‘micro-sinks’, which reduces water losses and erosion; c) increased surface roughness, which reduces the rate and speed of material transport (water, soil particles, nutrients, seeds); and d) the generation of microroughness that act as traps for capturing seeds and nutrients (such as organic matter in the form of litter, for example).

The implement can be used both in the finishing phase, that is, during the construction of the slope terrain, and in its maintenance operations, during the exploitation/operation phase. In the latter, the tool will allow mosaic decompaction treatments to be carried out on the surface layer of soil, minimizing damage to pre-existing vegetation. Unlike other decompaction tasks of an agricultural type, which remove the surface layer of the soil, with this implement, the decompaction is applied in a punctual manner and distributed discontinuously on the slope. This minimizes the impact that this operation could produce on the existing vegetation on the slope. On the other hand, the very design of the tool, which means that the central roller is always raised above the ground, at a minimum height of 15 cm, reduces damage to the existing vegetation cover.

The effects of the use of the tool on the final density of microdepressions that remain on the surface of the slope will depend on various factors, such as the nature of the lithological material that constitutes it, texture, presence of gravel, compaction, initial roughness of the surface; or the conditions of application of the treatment, such as the humidity in the soil, the number and direction of the passes that are applied, etc.; also of the physical characteristics and specific dimensions of the implement model used.

BRIEF DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, it is attached as part An integral part of said description is a set of drawings where, by way of illustration and not limitation, the following has been represented:

Figure 1. Schematic view with a possible embodiment of the implement.

Figure 2. Schematic view of a possible embodiment of the roller (1) and longitudinal section.

Figure 3. Schematic side view of a possible implementation of the implement.

Figure 4. Scheme of bar types and fastenings.

A. Radial bar (6), attached to the roller (1) by thread.

B. Asymmetrical diametral bar (7) fastened to the roller (1) by drilling for pins at the end that generates the spike and thickening of the opposite end.

C. Asymmetrical diametral bar (7) fastened to the roller (1) by means of holes for pins.

D. Symmetrical diametral bar (8) fastened to the roller (1) by means of holes for pins.

Figure 5. Average density of microdepressions generated by the implements of examples 9-12.

A list of the different elements represented in the figures that make up the invention is provided below:

1 = roller

2 = spike

3 = bearing

4 = fork

41 = fork side arms (4)

5 = roller hole (1)

6 = radial bar

7 = asymmetric diametric bar

8 = symmetrical diametric bar

PREFERRED EMBODIMENT OF THE INVENTION The present invention is illustrated by the following examples, which are not intended to limit its scope.

Example 1.

A hollow tube roller (1) was made of 4140 steel (low alloy steel of the Cr-Mo series -chromium molybdenum-), 1000 mm long and with external and internal diameters of 130 and 109 mm, respectively. A series of holes (5) of 20 mm diameter (figure 2) were made in the roller (1) in which 19 symmetrical diametrical bars (8) were inserted, perpendicular to its axis, to give rise to 38 spikes (2 ) 30 cm long and 20 mm in diameter each, made of tempered steel. As can be seen in figure 1, the 38 tines (2) were made from 19 diametral bars that cross the central axis of rotation and protrude on both sides of it (figure 4D), each symmetrical diametral bar (8) forming two (2) opposite tines of equal length. The distance between tines along the length of the roller (1) was set at 53 mm. The end of each point was ground into a 2.5 cm long flat chisel. To fix the symmetrical diametral bars (8), and to be able to change them for others if necessary, two holes were made in them 65.5 mm from the center of each bar, through which two pins were inserted.

In the implement design, the incision angles, along the roller (1), of the 19 symmetrical diametral bars (8), and the corresponding pairs of tines, were randomly distributed considering 4 possible orientations: 0 ^or , 45°, 90° and 135°. Same addresses on consecutive tines were avoided. Figure 3 shows how the tines (2) come out radially from the roller (1). The distribution of the 19 symmetrical diametral bars (8) along the axis was as reflected in the following sequence in which, from the left end to the right end of the roller (1), the incision angles of the diametral bars are indicated symmetrical (8) on the roller (1) itself. The first 8 values constitute a module that repeats to the right. The orientation of 0 ^o corresponds to the vertical direction that the roller (1) crosses from 0 ^o to 180° of its circumference:

0 ^or 135° 45° 0 ^or 90° 45° 135° 90° 0 ^or 135° 45°

0 ^or 90° 45° 135° 90° 0 ^or 135° 45° A fork (4) was also manufactured in tempered iron, 10 mm thick. At the ends of the roller (1) two pieces were welded that served as a cover and shaft for the bearings (3) which, once mounted on the roller (1), were fixed to the side arms (41) of the fork (4 ).

Example 2.

An implement like the one described in example 1 was made but, in this case, the length of the tines (2) was 20 cm, their diameter 25 mm and the distance between them 42 mm; In addition, 24 symmetrical diametral bars (8) and their corresponding 48 spikes were inserted. On the other hand, the roller (1) was made with an outer diameter of 150 mm. In this case, the elements used were made of steel. The sequence of the symmetrical diametral bars (8), from the extreme left to the extreme right of the roller, is indicated by the incision angles of the symmetrical diametrical bars (8) on the roller (1) itself and, in this example, it was the following sequence repeated four times:

0 ^or 30° 60° 90° 120° 150°

Example 3.

An implement like the one described in example 1 was made but, in this case, the external diameter of the roller (1) was 200 mm and its length was 1200 mm; the length of the spikes (2) was 25 cm with a diameter of 35 mm and the distance between them was 63 mm. In this example, 38 radial rods (6) with a total length of 28 cm were inserted into the roller, in which a thread was made at the blunt end to fix them to the roller (1) (figure 4A) and thus give rise to 38 picks (2) of 25 cm. In order for the radial bars (6) to give rise to the 38 tines (2) in the same positions as the symmetrical diametral bars (8) of example 1, the following sequence was followed, in which each pair of radial bars is located at the same distance from the ends of the roller:

0 ^or 180° 135° 315° 45° 225° 0 ^or 180° 90° 270° 45° 225° 135° 315° 90° 270° 0 ^or 180° 135° 315° 45° 225° 0 ^or 180°

90° 270° 45°225° 135° 315° 90° 270° 0 ^or 180° 135° 315°

45° 225°

Example 4. An implement like the one described in example 1 was made, with an external diameter of roller (1) of 200 mm and a length of 1200 mm; with a total of 48 tines (2) 20 cm long and 30 mm in diameter, placed 50 mm apart along the roller (1). Their distribution followed the same sequence as in example 2.

Example 5.

An implement like the one described in example 1 was made. In this case, asymmetrical diametric bars (7) were used with the fastening end thickened like a screw head (figure 4B) and a hole on the opposite side with respect to the roller diameter

(1) to reinforce the fastening of the asymmetrical diametral bar (7). 19 asymmetric diametric bars (7) were inserted to obtain 19 tines (2) with the following distribution:

0 ^or 60° 120° 180° 240° 300° repeating this pattern until all 19 positions are completed

Examples 6-9.

The implements described in examples 1-4, coupled to a backhoe, were used to loosen the surface of a 1 or 1.2 meter wide slope strip. Once the implement was installed on the tail end of a Palfinger articulating hydraulic crane, movement of this crane caused the implement to roll across the surface of a slope, up and down, or from side to side, forcing for the spikes (2) to dig into the surface of the slope to average depths of 5 to 10 cm. In this way, during the rolling of the tool, small earth movements were created, located at the insertion points of the tines.

(2), which we call microdepressions.

The action of the spikes (2) generated, on the surface of the slope, a series of small isolated areas, in which the superficial crust of the soil was broken, the surface layer was loosened up to the depth of insertion of the spike (2) and, locally, a new microrelief was generated. In the surroundings of the insertion points of the tines (2), a microtopography was created characterized by presenting a central depression with an ovoid plane, elongated in the rolling direction of the implement, and slightly raised sides, in the form of very large 'microcraters'. small diameter, affecting a variable area of between 25 and 50 cm ² . At the end of the intervention, the small areas of modified soil were spatially distributed on the surface of the slope in an isolated and discontinuous way, and almost randomly. The final density of these small areas depended on the specific configuration of the implement used, according to the different implements described in examples 1-4, in terms of the total number of tines (2), their distribution and their separation; but also depending on the number of application passes of the implement and the address(es) with which the operations were carried out on the slope. Table 1 shows the characteristics of each implement and the results obtained with a single pass of the implement over the ground.

Table 1. Characteristics of each implement according to examples 1-4 and its effects on a slope making a single pass, application or pass of the same, according to examples 6-9.

medium microdepressions.

Example 10-13.

Four implements were used with the same distribution and dimensions of the tines (2) as in the implements of examples 1-4, in which the roller (1) had a diameter of 15 cm, a length of 180 cm and, at Along the length of the roller, the tines (2) were set at 4, 5, 6 and 7 cm distance, respectively. With each of these four implements coupled to the articulated arm of a backhoe, the surface of a 1.8 meter wide slope strip was loosened, following the same steps as those described in examples 6-9. Figure 5 shows the relationship between the density of microdepressions, as a function of the effective length of the tines (2) on the implement, and the distances (d) between tines (2) on the roller (1). In this figure, the effective length of the tines (2) in meters (m) refers to the sum of the length of the tine (2) plus 1/2 of the diameter of the roller (1) and minus the average depth of incision of the tine in the ground (7.5cm); Num/m ² refers to the number of microdepressions per square meter and per pass. As indicated in examples 6-9, the surface of each microdepression ranged between 25-50 cm ² (Table 1), therefore, the surface decompacted by the implement in each pass ranged between 3.5-15 cm2. % of the total, depending on the distribution of the tines (2) of the implement used. It can be verified how the density of microdepressions per surface unit increases the smaller the distance between spikes and the shorter their length. Local characteristics such as climate, soil type, slope, presence of vegetation, previous surface treatments (spreading of topsoil and others), will determine the convenience of carrying out one or more passes.

Claims

1. Tool for loosening the surface of slopes that includes:

- a roller (1) that constitutes the bearing axis, - symmetrical diametrical bars (8) that cross the roller (1) giving rise to pairs of tines (2) that protrude from the roller (1), protruding each tine (2) of a pair at opposite ends of the diameter of said roller (1), or asymmetrical diametrical bars (7) or radial bars (6) inserted in the roller (1) and each of them giving rise to a spike (2) that protrudes of the roller (1) perpendicular to the diameter of said roller (1),

- a fork (4) in which the roller (1) is inserted by means of bearings (3) that allow its free rotation,

- elements for coupling the fork 4 to the arm of a civil works and/or agricultural machine, in which, taking as reference the circumference that delimits the surface of the roller (1), two prongs (2) contiguous along the length of the roller (1) protrude without repeating the same angle with respect to said circumference.

2. Implement according to claim 1, in which the tines (2) are between 20 and 45 cm long.

3. Implement according to any of the preceding claims, in which all the tines (2) have the same length,

4. Tool according to any of the preceding claims, in which the end of each prong (2) is chisel-shaped with a flat, conical or pyramidal tip.

Implement according to any of the preceding claims, in which the symmetrical diametrical bars (8), the asymmetrical diametrical bars (7) or the radial bars (6) are replaceable.

6. Tool according to any of the preceding claims whose elements are made of tempered metals and/or metal alloys.

7. Implement according to any of the preceding claims, in which the bars The symmetrical diametral bars (8) have two holes arranged in such a way that they are located one on each side of the surface of the roller (1) to which the symmetrical diametral bars (8) are fixed by means of pins or bolts.

8. Implement according to any of claims 1-6, in which the asymmetric diametral bars (7) have two holes arranged in such a way that they are located one on each side of the surface of the roller (1) to which the diametral bars are fixed. (7) by means of pins or bolts, or else, the end that does not generate a spike (2) has a greasing in the form of a screw head to fix the asymmetric diametral bar (7) to the roller (2).

9. Implement according to any of claims 1-6 that includes a thread on each radial bar (6) to fix said radial bar (6) to the roller (1).

10. Method for decompacting the surface of slopes that includes rolling an implement defined according to any of claims 1-9 along the surface of the slope, in a vertical and/or horizontal direction, so that the tines (2) are nailed into the slope surface to an average depth of 5-10 cm.