EP0161190A2 - Anchoring device comprising a hinged angular part - Google Patents

Abstract

The invention relates to a high performance anchoring device for any soil and easy to implement by known threshing or propulsion methods.

• a) une forme coudée dudit élément articulé et
• b) une localisation du centre de gravité entre le point d'attache de la ligne d'ancrage et l'articulation dudit élément articulé, ladite articulation et ledit point d'attache étant situés de part et d'autre du plan d'enfoncement (Δ).
  

It comprises a rigid main body having at least one end for attacking the ground at least one articulated element pivotally connected to said main body at least one anchoring line connected to said main body by a flexible connection. It also includes the following combination:

• a) a bent shape of said articulated element and
• b) a location of the center of gravity between the point of attachment of the anchoring line and the articulation of said articulated element, said articulation and said point of attachment being located on either side of the driving plane ( Δ).
  

Description

The present invention relates to a new anchoring device with articulated element having a bent shape for any soil, easy to implement by known methods of positioning (threshing, vibrofonishing, propulsion, launching and suction in the case of loose soils ...).

This technique is applicable both for anchoring on land and for making fixed anchor points in water, in particular in port facilities (marinas, mooring pontoons, etc.).

Patent FR 2,424,846 defines an anchoring system with free rotation of the attachment point, the latter being located in front of the center of gravity relative to the attacking end of the ground, but the installation of the system is done by pulling on the cable.

US Patent 3,282,002 presents an anchoring device with free rotation of the attachment point provided with a flat plate capable of tilting, the angular movement of this plate being limited by a stop. But this plate does not rotate by itself, it needs the help of a spring, or even an explosive, so that it blocks the anchoring.

The US patent. 3.888.057 defines a device where one must exert a traction on the eye of a free moving part located in the middle of the anchoring plate so that a lug perpendicular to the plate and located in the near front part from the leading end of the ground, can stand up and then tilt the anchor plate. Under these conditions and particularly in hard soils, the torque on the movable part may be too small for the device to be able to open and the plate will slip backwards without tilting.

The patents GB-A-2,089,862 and FR-A-2,470,823, FR-A-1,453,190 and US-A-1,982,963 also illustrate the prior art.

• Il s'agit de réaliser des points d'ancrage de haute tenue à terre et en mer pouvant supporter avec fiabilité une force de traction horizontale, inclinée vers le haut et même verticale vers le haut, de la tonne à la centaine de tonnes. Tout en étant susceptible d'être positionné de manière précise, le système d'ancrage doit être acceptable pour tous les types de sols (argiles, sables, sols rocheux par exemple).

The problem to be solved is therefore the following:

• It is a question of realizing anchor points of high resistance on land and at sea that can reliably withstand a horizontal pulling force, inclined upwards and even vertical upwards, from the ton to the hundred tons. While being capable of being positioned precisely, the anchoring system must be acceptable for all types of soil (clay, sand, rocky soil for example).

Anchor piles or generally groups of anchor piles generally solve such a problem, but they have the disadvantage of tearing off when the applied vertical force is too great.

Certain special anchors based on the principle of pivoting due to the eccentricity of the cable traction on the plate offers very poor reliability because the probability of correct operation is too low.

The invention consists of a new anchoring system making it possible to solve the problem posed.

• a) une forme coudée dudit élément articulé (9),
• b) une localisation dudit centre de gravité (G) entre ledit point d'attache (11) de la ligne d'ancrage (3) et l'articulation (10) dudit élément articulé (9), et
• c) un excentrement par rapport au plan d'enfoncement (A) d'une part dudit point d'attache (11) qui est fixe et d'autre part de ladite articulation (10), celle-ci étant située suivant un axe perpendiculaire audit plan dans la partie opposée à l'extrémité d'attaque du sol, de telle façon que l'application d'une traction sur la ligne d'ancrage (3) amorce le basculement de l'élément articulé (9) et le pivotement de l'élément d'ancrage.

It relates to an anchoring device comprising an anchoring element adapted to penetrate into the ground under the action of driving forces, in particular percussion, this anchoring element comprising at least one rigid main body having at least one end ground attack, said driving forces being exerted substantially along a driving plane passing through said ground attack end and a threshing or propulsion axis linked to the main body, at least one articulated element connected to pivotally to said main body and having a limited angular movement, at least one anchoring line connected to said main body by a flexible connection at at least one attachment point situated between said leading end and the center of gravity of the surface bearing of the main body, said attachment point being in front of the center of gravity, said sinking plane passing through said center of gravity, characterized by the following combination:

• a) a bent shape of said articulated element (9),
• b) a location of said center of gravity (G) between said point of attachment (11) of the anchoring line (3) and the articulation (10) of said articulated element (9), and
• c) an eccentricity with respect to the driving plane (A) on the one hand of said attachment point (11) which is fixed and on the other hand of said articulation (10), the latter being situated along a perpendicular axis to said plane in the part opposite to the leading end of the ground, in such a way that the application of traction on the anchor line (3) initiates the tilting of the articulated element (9) and the pivoting of the anchor.

The forces in particular of percussion communicate to the anchoring element an energy known as of threshing.

The angled shape of the articulated element (9) can advantageously have a concavity turned on the side opposite to said leading end (2).

The stated combination is capable of providing the best locking position for the anchoring device during the traction T exerted by the anchor line. It is adapted to make it move in the ground when it undergoes these efforts and to orient it to present an optimal master torque in order to mobilize the maximum stop of the earths.

By master-torque is meant the outline of the cross sections to the axis of movement of the anchoring element.

By flexible connection is meant here a connection which does not introduce substantially any moment of rotation at the point of attachment to the plate, such as a connection by wire, chain, ball joint or by an articulated threaded rod.

The burial in the ground is carried out by, driving forces F _E brought into play thanks to techniques for example of threshing, vibrofonishing, propulsion, launching, even suction in the case of loose soils, all known from the skilled in the art. The choice will depend on the nature of the soil.

The angular movement of the bent articulated element can be understood from 30 to 60 ° and preferably close to 45 ° relative to the driving plane (Δ).

• - les figures 1 et lA représentent schématiquement un premier type d'élément d'ancrage selon l'invention, vu de dessus et de côté respectivement,
• - les figures 2, 3, 4, 5, 6 et 7 illustrent la séquence de mise en place et blocage du dispositif selon l'invention dans différents sols,
• - les figures 8 et 9 montrent un autre mode de réalisation du dispositif selon l'invention et,
• - la figure 10 présente un autre mode de réalisation de l'élément articulé.

Examples of embodiments of the invention are illustrated by the drawings and diagrams annexed below where:

• FIGS. 1 and 1A schematically represent a first type of anchoring element according to the invention, seen from above and from the side respectively,
• - Figures 2, 3, 4, 5, 6 and 7 illustrate the setting sequence place and blocking of the device according to the invention in different floors,
• FIGS. 8 and 9 show another embodiment of the device according to the invention and,
• - Figure 10 shows another embodiment of the articulated element.

According to FIG. 1, the anchoring device, to resist a tensile force T at all height angles (horizontal, inclined and vertical upwards) implements at least one anchoring element designated as a whole by the reference 1, which is generally driven into the ground along the vertical by one of its ends constituting its attack end of the ground 2. An anchoring line 3 constituted in particular by a wire, a chain or a rod articulated thread, intended to transmit the tensile force T to be supported, by means of a traction pin 11, is attached to said element at at least one point by a flexible connection 5 such as, for example, a ball joint n ' introducing substantially no bending or twisting moment, at said point of attachment to the axis of traction 11.

The position of the latter on the anchoring element is chosen such that the point of application of the traction force to said element is located in front of the barycenter, or center of gravity G, of the bearing surface buried in the ground, or master torque of said anchoring element, towards said leading end 2. The anchoring element is characterized by a main body comprising a rigid dorsal part 6, on which a sole plate 4 provided with deflectors 15 rests on the inner side. This rigid dorsal part supports and transmits the threshing energy up to the leading end 2.

It is transmitted first of all on the anvil 7 which rests on the rigid part 6 and which is surmounted by a guide pin 8 intended to receiving the threshing element, this stud having a length h of 2 to 6 times its transverse dimension d. It is preferable to have a male stud to avoid any risk of jamming of the threshing element resulting from a mating phenomenon during the impact on the anvil. This nipple can have any shape (square, rectangular, round, oval or diamond for example).

In its part opposite to the leading end of the ground 2, the anchoring element is equipped with a bent articulated element 9 provided with stiffeners 18 in its internal part facing the stud 8, which pivots on a perpendicular axis 10 to the axis of the anchoring element along the driving plane A to a maximum position fixed by a stop 17 defining an angular movement α of 30 ° to 60 ° relative to the axis of the anchoring element which is in the driving plane A and which passes through the stud 8. The articulated element 9 has a flat part on the part of the elbow furthest from said articulation 10. According to another embodiment illustrated by FIG. 10, the part of the articulated element 9 furthest from said articulation axis 10 has a curved shape whose radius of curvature r is at least equal to the distance separating said articulation axis 10 from the ground attack end 2.

The length of this articulated element which separates the articulation 10 from the free end 9a of said element is between half and one tenth of the total length of the anchoring element and particularly interesting results have been noted with a value substantially equal to one third of the total length of the anchoring element.

The articulated element is such that the elbow in a vertical position at the time of insertion, that is to say aligned along the sole 4 is in the shadow of the master torque of the device, that is to say of the contour of the cross sections to the axis of movement of said anchoring element.

The distance from the attacking end of the ground 2 to the traction axis 11 constituting the point of attachment of the anchoring line 3 is between a quarter and a half of the total length of the element anchoring. Good performance was obtained when the distance was preferably equal to one third.

The ratio of the length of the anchoring element defined according to the driving plane (A) to the width of said element is between 1/3 and 10 and preferably between 1 and 5.

It has been noted that the distance from the leading end of the ground 2 to the axis of traction 11 or point of attachment is between a quarter and a half of the total length of the anchoring element and preferably equal to a third.

Good results have been recorded when the length of the articulated element 9 taken from the articulation 10 to its free end 9a, the distance separating the articulation 10 from said element at the attachment point 11 of the anchor line 3 and the distance separating said attachment point 11 at the attacking end of the ground 2 from the anchoring element 1 are each substantially equal to one third of the total length of the anchoring element 1.

The leading end of the ground can have an asymmetrical shape with respect to the driving plane (Fig. LA). It can also have a symmetrical shape with respect to the same penetration plane (Fig. 9).

It must also be symmetrical about a plane perpendicular to the driving plane passing through the threshing axis: its shape can then be for example pointed, straight (Fig. 8), or even trapezoidal such as that shown in the figure 1.

The leading end of the ground is extended by a blade 16, which can be for example steel or plastic, which puts "in the shadows * the sensitive elements of the device, in particular the bent articulated element, the anchoring line and the flexible connection. This blade extends over the sole 4 in order to properly guide the movement of the anchor.

• a) avant d'enfoncer l'élément d'ancrage 1, on attache audit élément la ligne d'ancrage 3 dont le diamètre est choisi inférieur à la dimension dudit élément en section par un plan perpendiculaire à la direction d'application de la force d'enfoncement, et on applique le long de l'élément, du côté opposé à son extrémité d'attaque, la portion de cette ligne d'ancrage voisine du point d'attache, de manière à le faire pénétrer dans le sol en même temps que l'élément,
• b) l'élément d'ancrage est conçu de façon telle que le maître-couple soit le plus faible possible pour profiter au mieux de l'énergie de battage. Il est préférable qu'il soit positionné en avant de tous les organes articulables (câble 3 et élément articulé 9) de sorte qu'ils soient protégés au cours du battage puisqu'ils sont dans "l 'ombre" de ce maître-couple.
• c) après avoir enfoncé ledit élément à la profondeur désirée, une traction sur la ligne d'ancrage 3 en surface, sous n'importe quelle hauteur vers le haut induit une composante verticale vers le haut qui fait immédiatement et spontanément basculer l'élément articulé 9 et pivoter l'élément d'ancrage 1.

The anchoring device according to the invention is implemented by the combination of the following steps:

• a) before driving in the anchoring element 1, the anchoring line 3 is attached to said element, the diameter of which is chosen to be less than the dimension of said element in section by a plane perpendicular to the direction of application of the force of penetration, and one applies along the element, on the side opposite to its leading end, the portion of this anchoring line close to the point of attachment, so as to make it penetrate into the ground at the same time time that the item,
• b) the anchoring element is designed in such a way that the master torque is as low as possible to make the most of the threshing energy. It is preferable that it be positioned in front of all the articulated members (cable 3 and articulated element 9) so that they are protected during threshing since they are in the "shadow" of this master-couple.
• c) after having pressed said element to the desired depth, a pull on the anchor line 3 on the surface, at any height upwards induces a vertical component upwards which immediately and spontaneously rock the articulated element 9 and pivot the anchoring element 1.

• - l'élément articulé 9 présente une forme coudée, la concavité du coude est tournée du côté opposé à ladite extrémité d'attaque 2. L'extrémité 12 de l'élément articulé 9 présente à son extrémité libre 9a un chanfrein dont le tranchant est dirigé vers l'extérieur.
• - les axes de traction 11 et de pivotement 10 de l'élément articulé 9 sont excentrés (Fig. 2) par rapport au plan d'enfoncement A passant par le centre de gravité G de l'élément d'ancrage. Cet excentrement favorise l'amorce du basculement de l'élément d'ancrage par rapport à un axe horizontal.
• - la position du centre de gravité entre le point d'attache sur l'axe de traction 11 et l'axe de pivotement 10 favorise le couple moteur dû à la traction sur la ligne d'ancrage 3 et à la pression des terres P sur l'élément articulé 9. La figure 3 schématise l'amorce du pivotement de la partie basculante.

Three inherent characteristics of the device according to the invention make it possible to trigger this tilting mechanism when these characteristics are used in combination:

• - The articulated element 9 has a bent shape, the concavity of the elbow is turned on the side opposite to said leading end 2. The end 12 of the articulated element 9 has at its free end 9a a chamfer whose cutting edge is directed outward.
• - The traction axes 11 and pivot 10 of the articulated element 9 are eccentric (Fig. 2) relative to the driving plane A passing through the center of gravity G of the anchoring element. This eccentricity promotes the initiation of the tilting of the anchoring element relative to a horizontal axis.
• the position of the center of gravity between the point of attachment on the traction axis 11 and the pivot axis 10 favors the engine torque due to the traction on the anchoring line 3 and to the pressure of the earths P on the articulated element 9. Figure 3 shows schematically the initiation of pivoting of the tilting part.

The tilting stops (Fig. 4) when the barycentric resultant R of the earth pressures at the start on the master-couple of the anchoring element aligns with the traction T on the cable. In this case, T is less than R.

If the anchoring element has been installed at a depth greater than the critical depth (2 to 4 times the largest dimension of the anchoring element), the mechanism for the abutment of underground soil is perfectly stable in meaning that there is a flow of soil material from the compressed side M _C to the decompressed side M _D. In such a situation, the static anchoring resistance or permanent anchoring strength F is perfectly stable (Fig. 5).

In the case of saturated soil (at the bottom of the sea) (Fig. 6), a rapid pull in relation to the flow of pore water in the pores causes a suction effect F _D which is added to the static resistance F previously mentioned to resist the dynamic forces on the anchor line.

S étant l'aire de l'élément d'ancrage, P_l et P₂ étant les pressions de l'eau interstitielle à l'avant et à l'arrière de l'élément d'ancrage, S son aire.This force F _{O is} written:

S being the area of the anchoring element, P _l and P ₂ being the pressures of the pore water at the front and at the rear of the anchoring element, S its area.

At shallow burial depth (Fig. 7), the anchoring resistance is limited by the driving force F of a volume of soil having the approximate shape of an inclined inverted cone situated above the system of anchoring (hatched area).

The device can optionally be removed from the ground. For this purpose, it will for example be provided with at least one extraction cable or any other known extraction means, fixed at at least one point 13 on the articulated element 9 and which optionally makes it possible to extract from the ground the anchor by vertical or backward pull from the surface.

A particularly advantageous embodiment of the anchoring device according to the invention is illustrated by FIGS. 8 and 9. Its more compact shape, its end for attacking the ground 2 symmetrical with respect to the driving plane and its main body 6 cut in an IPN or HPN profile on which rests a larger anvil 7 allow the anchoring device, due to a smaller master torque, good burial in hard soils as well as in soft rocks and good blocking position.

The types of anchors according to the invention can be arranged in series or in parallel while being interconnected by anchor lines. This device then increases the anchoring force.

Laboratory tests have been carried out with a device anchor weighing 2.8 kg. The anchor was hammered into sand saturated with water 1.35 meters deep. The characteristics of the anchor were as follows:

Under these conditions, a horizontal traction of 3 tonnes and a vertical traction of 1.5 tonnes were exerted without the anchor coming out of the ground.

The device according to the invention is suitable for work at sea and provides a very high anchoring strength for floating or semi-floating supports whatever the ground encountered. It can keep the structure rigorously in position and also ensure the longevity of the anchoring.

Claims (12)

1. - An anchoring device comprising an anchoring element adapted to penetrate into the ground under the action of driving forces, in particular percussion, this anchoring element comprising at least one rigid main body having at least one end ground attack, said driving forces being exerted substantially along a driving plane passing through said ground attack end and a threshing or propulsion axis linked to the main body, at least one articulated element connected to pivotally to said main body and having a limited angular movement, at least one anchoring line connected to said main body by a flexible connection at at least one point of attachment situated between said leading end and the center of gravity of the surface bearing of the main body, said attachment point being in front of the center of gravity, said sinking plane passing through said center of gravity, characterized by the following combination: a) a bent shape of said articulated element (9), b) a location of said center of gravity (G) between said point of attachment (11) of the anchoring line (3) and the articulation (10) of said articulated element (9), and c) an eccentricity with respect to the driving plane (A) on the one hand of said attachment point (11) which is fixed and on the other hand of said articulation (10), the latter being situated along a perpendicular axis to said plane in the part opposite to the leading end of the ground, in such a way that the application of traction on the anchor line (3) initiates the tilting of the articulated element (9) and the pivoting of the anchor. 2. - An anchoring device according to claim 1, characterized in that the bent shape of said articulated element (9) has a concavity turned on the side opposite to said leading end (2). 3. - An anchoring device according to claim 1, characterized in that the element (9) has a planar articulated part on the part of the elbow furthest from said articulation (10). 4. - An anchoring device according to claim 1, characterized in that the part of the articulated element (9) furthest from said articulation axis (10) has a curved shape whose radius of curvature r is at least equal to the distance separating said articulation axis (10) from the attacking end of the ground (2). 5. - An anchoring device according to any one of claims 1 to 4, characterized in that the articulated element (9) has at its free end a chamfer (12) whose cutting edge is directed outwards. 6. - An anchoring device according to any one of claims 1 to 5, characterized in that the angular angular movement of said articulated element (9) relative to the driving plane (A) is between 30 ° to 60 ° and is preferably close to 45 °. 7. - An anchoring device according to any one of claims 1 to 6, characterized in that the length of the articulated element (9) separating the articulation (10) from the free end (9a) of said element ( 9) is between half and one tenth of the total length of the anchoring element. 8. - An anchoring device according to any one of claims 1 to 7, characterized in that the anchoring element (1) comprises a guide member (8) of the driving forces, this member (8) having a length (h) of between 2 and 6 times its transverse dimension (d). 9. - An anchoring device according to any one of claims 1 to 8, characterized in that the attacking end of the ground (2) of the anchoring element (1) has an asymmetrical shape relative to the sinking plan (A). 10. - An anchoring device according to any one of claims 1 to 8, characterized in that the attacking end of the ground (2) of the anchoring element (1) has a symmetrical shape relative to the sinking plan (A). 11. - An anchoring device according to claim 1, characterized in that the length of the articulated element (9) taken from the articulation (10) to its free end (9a), the distance separating the articulation (10) of said element at the point of attachment (11) of the anchor line (3) and the distance separating said point of attachment (11) from the leading edge of the ground (2) of the element anchor (1) are each substantially equal to one third of the total length of the anchor (1). 12. - An anchoring device according to claim 1, characterized in that the ratio of the length of the anchoring element measured along the driving plane (Δ) to the width of said element is between 1/3 and 10 and preferably between 1 and 5.

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