EP0786035B1 - Device for anchoring the foundation of a structure in the ground - Google Patents

Abstract

PCT No. PCT/FR95/01316 Sec. 371 Date Apr. 4, 1997 Sec. 102(e) Date Apr. 4, 1997 PCT Filed Oct. 9, 1995 PCT Pub. No. WO96/12068 PCT Pub. Date Apr. 25, 1996Device for anchoring the foundation of a structure in the ground comprising an anchor (1) and a pull line (8) along an axis (ZZ'), the end (19) of a terminal portion (18) thereof being integral with a fastener (9) secured to the body of the anchor (1). The body comprises a front wing element (2) shaped to go into the ground along an axis (XX') and a rear wing element (3) opposing the pull of the line (8) by abutment in the ground once the anchor is tilted in the ground. In one embodiment, the fastening location (9) is offset to the axis (ZZ') of pull in the direction of the axis (XX') of the anchor body (1). The anchoring device comprises a component (7) for guiding the terminal portion (18) of the pull line (8) between the fastening location (9) and the axis of pull (ZZ'), whereby the fastener is offset. The anchor body (1) comprises a fin-shaped element (6) located on the other side of the plane of the front wing element (2) in relation to the guide component (7).

Description

The present invention relates to a new device anchor of structural foundation in the ground.

The technical sector of the invention is the field of realization of anchors that we drive into any terrain, either from the surface of an underground gallery or gallery wall or other, by threshing, vibratory driving, launching or other, up to a certain depth or distance from said. surface and then on which by a pulling device which can be a cable, a chain, a strap or other deformable rod provided the connection with the anchor either flexible and / or articulated, a traction is applied from this surface so that said anchor tilts into a position transverse to the direction of traction and that it then allows resist by opposing a maximum surface area of its sails to this pulling and thus immobilizing the pulling up to a certain value of effort of this traction.

The main applications are, as in all Known devices of the same type, anchoring guy stakes, cables, massifs, structural support plates, etc ... and more especially when you want to obtain a foundation resistance even in case of poor tensile strength of the soil alone, creating then a massif formed by the soil itself which is put in prestressed for this, as taught in patent EP 317458 published on May 24, 1989 and deposited by the Company T.S.I. and which describes also the whole technique of implementing an anchoring of a foundation, whose principles we will not recall here known.

There are also many devices allowing anchors in the ground following the implementation described above for define the technical sector of the invention although it is not of course to realize then a solid mass constituted by the soil itself prestressed, subject of the above patent; some of these anchor devices have been the subject of patent applications in particular for devices intended to ensure tilting or the inclination of the anchor: we can cite for example the request FR 2470823 published June 12, 1981 by Mr. CARGIOLLI Pierre who describes a device for soft ground which allows the tilting of the anchor by placing the anchor point of the anchor line in front of the surface center so that during the tensioning, the effort of opposition of materials which applies to the rear part of the airfoil either, thanks to the larger surface concerned, greater than the one opposed by the front part which thereby rises. However this method is not reliable because the anchor can go up a lot and even get out of the ground before the rear of the wing can place it in abutment and the planned process then takes place: thus the planned anchoring depth is no longer respected.

To avoid the above uncertainty, the EP patent application 161 190 published on November 13, 1985 of the I.F.P. has a shutter articulated on the rear of the anchor wing to initiate more quickly block before tilting. Such a device does not cannot, however, prevent a significant rise in the anchor during tensioning especially in cases where to facilitate the sinking, a pilot hole was made with an auger: part of the flap is in a vacuum and its stop action is reduced and delayed. In addition, given the efforts involved, the flap joints break. On the other hand, when driving the anchor, materials can get caught between the flap and its stop and to prohibit its movement therefore its office. This brings back to the case previous.

We can also cite the patent GB 2089862 published on June 30 1982 by WISE E.G. which describes an articulated device for causing after sinking the tilting of the wing by rotation around a axis eclipsable under the thrust force of the threshing rod previously changed position by a 180 ° rotation: this device is complicated and cannot prove reliable in situation.

Finally, we know different anchoring systems with ribs and fins on the front part of the anchor to facilitate sinking in the desired direction, combined with systems of articulation of the traction point offset from the axis the anchor, firstly to release the cable from the rod jacking so as not to damage it and on the other hand for facilitate the tilting of the anchor after its insertion: such device is described for example in patent EP 313936 published on 3 May 1989 of FORESIGHT INDUSTRIES INC. ; however, if actually control of the direction of digging into the ground is thus better ensured, the pivoting of the anchor itself in the ground is not, at least to the desired depth, and is not performed reliably.

Thus, it is observed that most of the current anchors, except to associate with them complex, mechanical devices and themselves therefore unreliable and / or complicated to use, actually go back a lot, and even to the point of being above ground, without having tipped over when a tensile force is applied to the anchor line which must connect to the surface: the tilting and blocking are not done more or less safe than in terrain which must close behind the anchors after their passage and are fairly dense; this limits the cases of figures and use. In too compact clayey soils whose footprint the anchor remains open behind it, or in too soft sands of muddy type, the known anchors do not immediately fall over or not even at all when subjected to traction, which goes back too far and of course does not guarantee a anchoring depth.

However, when we want to ensure a good performance of it, especially for the application to the soil prestressing as described in the previously cited patent EP 317458, it must be possible to be sure of this tilting depth to guarantee the existence of the volume of land necessary for the constitution of the foundation, and this whatever the nature of the soil, the anchoring depth being depending on it and the effort you want to resist.

The problem is therefore to be able to make a device anchor, comprising an anchor and a line of traction, and the implementation essentially allows the tilting of the anchor as soon as the desired depth reached to then ensure said anchoring to a given depth and this in any type of terrain; another objective of the invention is also to achieve the insertion of said anchor in said soil by controlling the direction without risk of great deviation.

One solution to the problem posed is a device for anchoring foundation of structure in the ground comprising an anchor and a line tensile along an axis ZZ 'offset preferably with respect to that XX 'of the anchor, and whose end of one end is integral a point, or a fastening piece, fixed to the body of the anchor, which body includes a profiled front wing to penetrate the ground along its axis XX 'and a rear wing to oppose the effect of traction of said line by abutting in the ground after the anchor has penetrated therein by pressing along its axis XX 'and tilted; according to the invention, the anchoring device comprises a piece of guidance and support relative to the body of the anchor, of said end of the line between said attachment point and its axis of ZZ 'traction, which support piece transmitting an effect to the body of the anchor transverse to the axis, creating a tilting torque when said end is energized by the line tensile along this axis (ZZ ') and said anchor body includes a fin located the other side of the front wing plan, with respect to said part of guiding and comprising a heel which leans and locks in the ground as soon as the tensioning of the traction line along the axis (ZZ ') and tending to raise the anchor.

In an embodiment in which the line of traction is deformable, such as a cable, said attachment point of the line of traction being offset with respect to the axis ZZ 'of traction thereof towards the axis XX 'of the body of the anchor, said guide piece ensures said offset and is a part of the body of the anchor on which rests on said end of the traction line or cable, fixed said attachment point.

According to another preferred embodiment, in especially when the anchoring depth is reduced, of the order of less than a meter, as in urban areas and for limited traction, said guide piece is constituted by a piece rigid which forms the end of the line of traction, which is articulated around said point of attachment and which rests on the body of the anchor by a spring housed therein and which is compressed in threshing position, between the rigid end of said line of traction and said body of the anchor. The pull line can be itself fully rigid, and therefore in one piece, articulated directly in the anchor body, around a point of attachment secured to its end such as a pin which can either be offset from the traction axis XX ', the end of the part rigid then bent, be aligned with it.

In an embodiment which can be one of those cited previously, said anchor also comprises another fin of protection in front of said guide piece perpendicular to the plane of the front wing and of a height h with respect thereto greater than the offset distance from the axis ZZ 'of said cable traction relative to the front wing of the body of the anchor; of preferably, said fins respectively called protection and tilt, are symmetrical with respect to said sail plane front, identical and both located in front of said piece of guidance.

The result is new foundation anchors structure in the ground comprising an anchor as defined previously which makes it possible to solve the problem posed and to reach the objectives of the invention, which the devices do not allow known to date.

Indeed, one of the great innovations and originalities of the present invention is to define well the connection of the end of the anchor line with the anchor itself following a well position determined whereas so far all the known anchors at contrary included flexible and free connections without guidance nor forced support because we were always looking for the alignment of the line of traction and its point of attachment to the anchor as soon as it is placed under tension: this absolutely does not create a support force voluntary R, transverse to the direction of traction ZZ ', such that shown in particular in Figures 2 and 8 illustrative described below, thus allowing according to the present invention a instant pre-tilting of the anchor, either when power is applied of the traction line, i.e. as soon as the threshing rod is removed, whatever the nature of the terrain. Many tests have moreover proved that with anchors according to the invention, one obtains said tilting to the desired depth, which the current devices; these indeed were not looking for such precision in depth since it is essentially in these known devices for obtaining an anchorage to withstand a force traction without considering the participation of the surrounding soil, whereas here, for the application to an anchorage as defined in the patent application No. EP 317458 mentioned in the introduction, the depth is essential to obtain sufficient participation from the ground and then resist a given effort.

Thus, according to the examples described below, it will be noted that the end of the anchor line is always intentionally set in contact by a guide and support piece with the body of the anchor, directly or by an intermediate spring, which part is one of the essential elements of the present invention, whereas in known anchor lines, even articulated and offset by relative to the axis of the anchor, it is only transmitted to the body of the anchor force aligned in the applied direction of tension without causing a transverse force of reaction on the anchor.

In addition, the presence of the fin which can therefore be called pre-tilt, as indicated above, perpendicular to the plane main sail of the anchor, and located on the other side in relation to to the line of traction, allows, in addition to better guidance during sinking the anchor in a given direction, to constitute a almost instant stop heel from the start of the effort traction; this creates a real immediate pre-tilt couple anchor, in combination with the specific line layout anchor according to the invention, as described in one of the modes of embodiment of Figure 2 or Figure 8, and shown in implementation work in Figures 7 and 11 below.

In known anchors, the tilting moment constituted only by the traction applied to the lever arm formed by the offset of the line of traction relative to the axis of the anchor is not sufficient to ensure said tilting according to the terrain encountered as said before, except waiting for some raising the anchor in its hole until the friction allow to obtain a tilting torque, when the rear of the wing has the good fortune to come to a stop. In fact, this shift is due to the need to release the penetration axis of the anchor in the soil to let the threshing rods pass, and various solutions have been proposed, like those mentioned in the introduction to ensure really the tipping, proving that the moment of the above forces is considered insufficient, but these solutions have not has produced convincing results to date.

The results obtained with the elements of this invention, however allow automatic pre-tilting immediate and irreversible placing the anchor in immediate abutment, said stop being achieved thanks to the complementary fin and the part aft wing, with little or no lift and so systematic.

In addition, the addition of another symmetrical fin of the first on the other side of the sail plan, allows line protection anchor located behind, while assisting in guiding when the anchoring of the anchor in the ground.

The embodiment described in Figure 8 below, with a rigid traction line which can be in one piece between the attachment point and surface, avoids having to base and attach a cable or other deformable line to an anchor and / or binding on the anchor, which of course limits the cost of manufacturing.

In this embodiment, the existence of the recessed spring in the body of the anchor and bearing on the end of the line anchor, allows you to get, when you decide and immediately then, the pre-tilting of said anchor and accompanying the tilting it up to an angle of around 30 °, allowing irreversibly, hooking the back of the airfoil in the ground at a determined and desired height, which is all the more necessary, when we are shallow in the soil, and we want to obtain optimum tensile strength; the movement is then independent of the shape of the anchor and allows give it all the more favorable forms of penetration anchor in the ground.

Other advantages of the present invention could be cited but those cited above already show enough to prove novelty and interest. The description and figures below represent examples of embodiment of the invention but are in no way limiting: other embodiments are possible within the scope and scope of this invention, in particular by changing the shape of the anchor body which can be carried out, either in mechanical parts added in mechanically welded, or in molded or forged parts, or in other materials, etc ...

Figure 1 is an overall perspective view of an example of realization of an anchoring device according to the invention.

Figure 2 is a longitudinal sectional view of a device according to Figure 1.

Figure 3 is a simplified view of the same device as that shown in Figure 2.

Figure 4 is a sectional view along CC 'of the device of the Figure 3.

Figure 5 is a longitudinal sectional view of a device according to the invention, according to another embodiment.

Figure 6 is a cross-sectional view along DD 'of Figure 5 device.

Figure 7 is a representation of the different phases of tilting during the implementation of a device according to the Figures 1 to 6.

Figures 8 to 10 show another embodiment of a device according to the invention: FIG. 8 is a sectional view longitudinal along VIII / VIII 'of the top view according to the figure 10 and FIG. 9 is a sectional view along line IX / IX 'of FIG. 8.

Figures 11 and 12 are representations of implementation operation of a device according to FIGS. 8 to 10.

The structure foundation anchoring device in the ground indeed comprises in a known manner an anchor 1 and a line of traction 8, which is applied along an axis ZZ '.

The body of the anchor 1 is made up of various elements such as that in particular a profiled front wing 2 to penetrate the ground and which can consist of two bevelled wings their ends and symmetrical on either side of the plane defined by the axes of the traction line ZZ 'and of the direction XX' of anchor penetration: said profiled front wing 2 thus allows the anchoring of the anchor in the ground along said axis XX 'thanks to the thrust transmitted by a threshing element 20 which is pressed from the surface of the ground or the wall of the ground in which one wants to make penetrate said anchor and which is housed along the axis XX 'to the rear of the anchor in a housing 4 provided for this.

Said body of the anchor 1 also comprises on either side of this housing 4 a rear wing 3 in the extension of the front wing 2 and of sufficient area to allow oppose the traction effect of line 8, in the position anchor, making a stop in the ground and as shown in the Figure 7, after the anchor has entered and after a first step tilting, said stop being represented by the force F'2 on this Figure 7, while the front wing 2 also ensures the other side of the axis ZZ 'a reaction by stop in the following soil force F'3: it is the combination of these two reaction forces in the ground which ensure the balance of the anchor and the restraint of the traction line 8 subjected to the traction force T4 desired after placing the anchor at the given depth.

The end of one of the ends 18 of the traction line 8 is secured to a point or attachment piece 9 located in the middle of the body of anchor 1, which attachment point 9 must be offset from the ZZ 'axis of traction thereof towards the XX' axis of the body of the anchor 1 for the embodiments of Figures 1 to 7, and even preferably located along said axis to obtain a torque the highest possible tilt, while in the realization of Figures 8 to 12, this offset may be nonexistent or at least less important since the desired tilting torque and necessary is then ensured by the power of the spring 24 put in compression.

In Figures 1 to 7, said guide and support piece 7 is part of said body of anchor 1 and on which said base is based end 18 of the pull line, which is then necessarily deformable, such as a cable, which will be cited as reference in the following description of Figures 1 to 7, which end 18 is fixed to said attachment point 9: this piece of guide and support 7 allows the end 18 of the traction line 8 to be guided between said attachment point 9 and the traction axis ZZ ' proper, ensuring said offset and in shape such that said end 18 of the traction cable 8 forms an angle β of more than 10 ° and less than 90 ° with the axis XX 'of the anchor, and preferably between 60 and 90 °.

According to the embodiment of Figures 2 or 3 or 4, said point or attachment piece 9 consists of a hinge end of in this case cylindrical shape of revolution at least along an axis perpendicular to said axes XX 'and ZZ', fixed and integral with the end 19 of the end 18 of the cable 8 on which it is breeched: said end piece 9 can thus be a cylindrical part or a spherical part: it can also be a fastener in the body of the anchor; the room constituting the end piece 9 may include a hollow appendage in which pass the end 18 of the cable 8: it is this appendage which then comes resting against the guide piece 7 of the anchor body. Said end piece 9 is housed and articulated in a housing 10 in the body of the anchor in which it can rotate at least along the perpendicular axis to said axes XX 'and ZZ' and communicates with an orifice 20 in the form of trunk through which said end 18 of the cable passes. Of preferably, this accommodation is located in front of the surface center of the entire wing 2, 3 of said anchor.

As can be seen in the representation of Figure 2, when we then pull along the axis ZZ 'by a force T on the line of traction and anchoring 8, said force is transmitted to the end 18 from said traction cable 8 to the end-piece or attachment point 9 along the axis YY 'forming with the axis ZZ' an angle α which, in the original position of the pre-tilting of the anchor, when this is at the bottom of the hole, for example, is equal to the angle β defined above.

The combination of the tensile force T and the force R1 of reaction generated by the nozzle 9 to oppose the transmission of this traction on the end 18 of the cable, creates a resulting force R transversely to said axes XX 'and ZZ', creating a couple of immediate tilting thanks to said support of the end 18 of the line 8 on the support piece 7: the inclination of this force reaction R of course depends on the initial angle β; we take preferably an angle of 60 to 90 ° but a very small angle of the order 10 ° would always have a reaction force; we limit the angle at 90 ° maximum because beyond, a higher angle would create a unnecessary tilting force during the actual anchoring of the anchor in final position in the ground in which it must be maintain, which even would be possibly unfavorable for an effect prestressing of the soil in which we want a symmetrical distribution on the wing without any additional tilting effort.

Said body of the anchor 1 may also include a fin 5 of protection in front of said support piece 5 to protect it and the cable when sinking into the ground, perpendicular to the plane of the front airfoil 2 and a height h relative to the latter, greater than the offset distance d of the axis ZZ 'of said cable traction 8, as well as a fin 6 located on the other side of the plane of front wing 2 with respect to this first fin 5.

The two so-called fins 5 and 6 are preferably symmetrical by compared to sail plan 2 and identical in order to balance the forces when hitting the anchor and so and thanks to their combination with the front wing 2, make it possible to guarantee the direction of threshing.

As illustrated in Figure 7, said fin 5 or rib upper which is profiled on the front to allow penetration in the ground cuts it and protects the cable 8, while the rib lower or fin 6, also profiled on the front of the same way, cuts the ground like the upper rib, and moreover, by its heel effect 16, made tilting stop as illustrated on the Figure 7.

Figure 3 is therefore a representation of the device according to the Figure 2, in section AA 'according to Figure 4, while the latter is a section along CC 'of the same device in Figure 3: the housing 10 end piece 9 and the latter are cylindrical in shape.

According to the representation of the examples of Figures 5 and 6, the end 19 of end 18 of cable 8 can be directly breeched in a housing 17 of the body of the anchor 1 and said support piece 7 is extends beyond the support area of the end of the cable 8 at 90 ° with axis XX 'up to said housing 17 to constitute therewith said attachment point 9.

According to Figure 7, three positions of the anchor after its installation for example by threshing leaving behind it a well 15 of axis PP 'in the soil 11 in which it has been pushed to the desired depth from which it will tilt, the tilting stroke being known; according to the types of ground, it represents half the length of the anchor. There is a slight slip due to the settlement of ground around the anchor. The axis PP 'of the well 15 is combined during the entire phase of the anchor being pushed in with the axis XX 'thereof.

The first step is that of the immediate, immediate and irreversible, when tensioning the cable or line anchor 8 subjected to the T2 force, thanks to the composition of the parallelogram of action and reaction forces as described according to Figure 2. As an example, we can give values of the resultant force R of pre-tilting and then tilting following the angle of the anchor for a tensioning force T2 for example constant of one ton: at the start, if the angle α or β is 90 °, R = 1.4 tonnes; then when the angle decreases with tilting, such as in position 13 of Figure 7 for example, at 60 ° but which could also be the case of an α and β position of 60 ° initial, R = 10,000 Newtons or approximately one tonne; then in the third stage of tilting or in the initial position such as in position 14 by example where α would be 40 °, R = 6,840 Newtons; then even beyond, when α decreases to 20 °, the resulting force R also decreases to 3480 Newtons but it doesn't really matter anymore since then, the engagement of the airfoils, in particular the rear airfoil, is sufficient to finish the rotation from position 14 to position final anchoring.

This force R is therefore of course the most important at the start of rotation during this pre-tilt step in which this force, if we take a sufficiently large angle α, causes a tilting torque, due to the distance of this resultant R to rotation point G, large enough to ensure the tilting in the field, whatever the nature of it.

In position 12 of Figure 7 just after pre-tilting, the force transmitted T2 in the anchor line continues to cause a force and therefore a tilting torque on the workpiece support 7 as indicated above, which will therefore decrease gradually as the anchor swings and therefore of the reduction of the angle α, knowing that the angle β will of course remain constant until the end of the changeover. From an angle a sufficient, it is the lower fin 6 which comes into play by forming a support and blocking point in the ground by its heel 16, and creating a reaction force F1 which opposes the raising of the anchor: from position 12 thus indicated, a couple of additional tilting between this reaction force of soil F1 and T2 traction.

In the next tilting phase 13, while the heel 16 of the lower fin 6 will disappear and therefore reduce the force of reaction F'1 in the ground, it is then the aft wing 3 of the anchor who engages completely in it, whereas at the beginning, only his heel 22 clings and creates a significant F2 reaction force which takes, if you will, the change in force F1, F'1, while the force reaction of the ground to the front wing F3 begins to also gain importance, but of a lower value than the force rear F2 due to the fact that the front wing has an apparent surface in the ground, lower, allowing the anchor to continue to to toggle.

The end of the tilting illustrated for example in position 14 is continues by balancing the reaction forces of the ground F'3 and F'2, which also compensate for the tension force T4 applied to the cable 8, relative to the position of the pull point of it, which is preferably in front of the surface center of gravity, until you have a stability of this balance: the two couples generated by these two reaction forces in the soil to compensate and therefore cancel each other out to obtain this balance at the desired final angle of the axis XX 'by relative to the initial threshing axis PP 'or traction ZZ' of the cable 8.

As indicated in the introduction, it is obvious that the cable 8 used in this description can be replaced by any deformable and / or flexible line allowing the transmission of tensile forces, such as a chain, belt or any other device such as a deformable rod.

Figures 8 to 12 show another embodiment of the invention, the main application of which is anchoring at low depth up to about one meter, and in which said piece of guide and support 7 is not part of the anchor body as previously, but of the traction line 8: it is constituted by a rigid part forming the end 18 of the traction line 8, is supported by a spring 24 on the body 1 of the anchor and is articulated around point 9. In this case, the actual traction line 8, can be in one piece to the ground surface, understand end 18 and be made in one piece up to and including the joint and attachment point 9; the line of traction up to surface can also consist of a deformable line as in Figures 1 to 7, and be fixed near the anchor 1 on the other end, relative to the attachment point 9, of said part end 18 which is then only rigid.

We naturally find in this embodiment, the elements already described above, such as the main body 1 of the anchor, comprising a bulge forming a fin, in which is located the joint and anchor point 9, and a fin forming spur-stop 6 on the other side; the rear part of the body 1 of the anchor has a bore 4 for guiding the end of the threshing rod 20, the rear 22 of the body 1 serving inter alia anvil to said threshing rod as shown in Figure 11. The sail of the anchor is in its rear part 3 of constant section, and in its front part 2 of tapered section, for penetration into the ground 11 with two lateral heels 23, favoring the attachment in the ground during traction T on the anchor line 8; the mode of implementation shown in Figures 11 and 12, corresponds to same phases described as in the representation of FIGS. 7 to which we will refer, in particular for the pre-tilt positions 12 and 13 of Figures 7a and 7b.

Such an anchor is designed to offer less resistance to soil penetration, although pilot holes can be made beforehand, these shapes being tapered in arrowheads, and all the wing elements connecting to the actual body of the anchor by large radii of curvature of form.

In the main body 1 of the anchor, a housing is practiced 10 in which the end attachment point 9 of the line is embedded anchor 8, such as by a tenon joint or along an axis or a cylindrical journal forming part of said anchor line; which housing 10 opens with a light 20 on the face which is can call dorsal of the anchor, for passage and rotation relative to the anchor, about 90 ° for example, from the rigid piece 7 at the end 18 of the anchor line 8 between the threshing position and the final anchoring position; this anchor line can be put on during its assembly by the ventral side of the anchor where said housing 10 opens.

The articulation 9 is located slightly in front of the center surface of anchor 1, and another bore 25 located on the rear of this articulation 9 contains the spring 24 and can communicate with that of the threshing rod: this spring 24 gives an impulse of pre-tilting and therefore attachment of the anchor when it is set place when removing the threshing rod 20. As far as the entire traction line 8 is rigid to the surface, we can maintain this righting compression from the surface for the duration of the threshing, otherwise, if the pull line is at less partially deformable, a lug or any means of support can be integral with the threshing rod 20 to keep the end 18 against it until it is withdrawn. The spring 24 is of the sausage and works on compression: it is well protected from the environment around 11 during threshing because it can be fully accommodated in the bore 25, which is then closed by the rigid part 7, preventing any ingress of gravel or other particles from the ground which could then hinder its expansion.

The bent bent shape of the end portion 18 of the anchor line, makes it possible to make up for the traction offset ZZ 'by relative to hinge axis 9: this offset can be useful for embed the pin 9 in the anchor body without having to overdo it magnify it, but may not exist due to the existence of the spring 24 which gives the tilting torque by its force of reaction R. We could even consider a rigid traction line 8, arranged and articulated along the threshing axis XX ': either then it is the traction line 8 itself which ensures threshing, or the threshing rod 20 is hollow and surrounds the traction line 8; the spring 24 would be located in a bore offset from the axis XX '.

In tests carried out with an anchor 200 millimeters long by 70 millimeters wide, with a sail area of 105 cm ² , made of mechanically welded steel, and weighing around 1.2 kilograms, with a resistance of the rigid anchor line of approximately 14,000 Newtons, and an anchor resistance of 30,000 Newtons, immediate tilting is obtained with a spring force of at least 150 Newtons, at the desired depth and an anchor capacity nominal in hard soil around 7,000 Newtons.

Claims (10)

1. Device for anchoring the foundation of a structure in the ground, comprising an anchor (1) and a traction line (8) for traction along an axis (ZZ'), the tip (19) of one end (18) of the line being secured to a point (9) or attachment piece that is fixed on the body of the anchor (1), which body includes a front wing unit (2) shaped to penetrate into the ground along its own axis (XX'), and a rear wing unit (3) for opposing the effect of traction on said line (8) by coming into abutment with the ground after the anchor has penetrated therein and has tilted, characterized in that it includes a piece (7) for guiding and supporting said end (18) of said traction line (8), which bearing piece (7) disposed between said attachment point (9) and the traction axis (ZZ') transmits to the body of the anchor (1) a force transversal to the axis (ZZ'), thereby creating tilting torque when said end (18) is put under tension by the traction line (8) along said axis (ZZ'), and said body of the anchor (1) includes a fin (6) situated on the other side of the plane of the front wing unit (2) relative to the guide piece (7) and including a heel (16) which bears against and jams in the ground once the traction line (8) is put under tension along the axis (ZZ') and tends to cause the anchor to be raised.
2. Device according to Claim 1, characterized in that said guide piece (7) is constituted by a rigid piece forming the end (18) of the traction line (8) hinged about the point (9), and bearing against the body (1) of the anchor via a spring (24).
3. Device according to Claim 2, characterized in that said rigid piece (7) is angled and its end (18) terminates in a journal constituting said attachment point (9) of the traction line (8).
4. Anchor device according to Claim 1, characterized in that said attachment point (9) of the traction line is offset from the traction axis (ZZ') thereof towards the axis (XX') of the body of the anchor (1), said guide piece (7) ensuring said offset and being a portion of the body (1) of the anchor on which said end (18), fixed to said point (9) of the traction line (8), which is deformable, bears.
5. Device according to any one of Claims 1 to 4, characterized in that said attachment point (9) is constituted by an endpiece of cylindrical form of revolution at least about an axis perpendicular to said axes (XX') and (ZZ'), which endpiece is stationary and secured to the tip (19) of said end (18) of the traction line (8) and is hinged in a housing (10) formed in the body of the anchor, in which housing it can rotate.
6. Device according to Claim 4, characterized in that the tip (19) of said end of the line (8) is directly socketed in a housing (17) of the body of the anchor (1) and said bearing and guide piece (7) extends beyond the bearing zone for the end (18) of the line (8) at 90° to the axis (XX') as far as said housing (17) to constitute therewith said attachment point (9).
7. Anchor device according to any one of Claims 3 to 6, characterized in that said attachment point (9) is situated on the axis (XX') of the body of the anchor.
8. Device according to any one of Claims 3 to 7, characterized in that the angle β between the end (18) of the traction line (8) and the axis (XX') of the anchor (1) is included between 10 to 90°.
9. Device according to any one of Claims 1 to 8, characterized in that said anchor (1) includes a protective fin (5) in front of said guide piece (7) and extending perpendicularly to the plane of the front wing unit (2) over a height h therefrom that is greater than the offset distance of the axis (ZZ') of said traction line (8).
10. Device according to Claim 9, characterized in that the two fins (5, 6) are symmetrical about said plane of the front wing unit (2), are identical, and are both situated in front of said guide piece (7).

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