EP0193513A1 - Method for making a pile of concrete or a similar material using a drilling tube having wings, and drilling tube therefor - Google Patents

Abstract

The invention relates to a method for making a pile of concrete or a similar material in the ground and to a drilling tube for carrying it out. This drilling tube is characterised in that it comprises a hollow tube (1) open at least at its lower drilling end (1a) and equipped externally and longitudinally with at least two wings (4), the lower edge (4a) of which is adjacent to the open lower end (2) of the tube (1) coming into direct contact with the ground, the tube being equipped on its periphery with orifices (6) on either side of each wing (4). This ensures a very low drilling resistance making it easier to obtain a better drilling rate. <IMAGE>

Description

The present invention essentially relates to a method for producing a pile of concrete or similar material using a finned tube and a driving tube for its implementation. Already known from Belgian patent n ° 885 931 a driving pile comprising fins 4 fixed or not fixed to the external surface of the tube 1. These fins are welded to a plate 3 directly or by means of a cylinder 15 forming a driving sole which is of a section larger than the section of the tube itself.

The arrangement described in this prior patent is provided so as to provide large outlet orifices 7 between the lower end 4a of the tube and the plate 3 so as to facilitate the injection of the concrete into the space cleared by the insertion of the sole formed by the plate 3 of larger section than the section of the tube itself.

The drawback of such a structure lies in the fact that the driving sole offers a relatively high resistance to sinking, slowing down the driving operation.

On the other hand, the presence of the driving sole repels the earth and therefore there is no intimate mixing of the concrete or similar material with the earth near the driving tube while it is important to achieve an intimate mixing. between earth and concrete or similar material to make a very large lift pile.

The present invention therefore relates to the new technical problem consisting in the production of a pile of concrete or similar material of great lift even in soft soils and with great ease of penetration allowing high driving speeds.

This technical problem is solved for the first time by the present invention in a satisfactory manner.

Thus, the present invention relates according to a first aspect to a method of making a pile of concrete or similar material in the ground, comprising the insertion of a hollow tube in the ground provided externally with fins, allowing the injection of '' a curable fluid material, for example a mortar, around said tube as the tube is pushed in, for example by threshing, said tube being left permanently in the ground, - characterized in that a hollow tube open at least at its lower driving end, provided externally and longitudinally with at least two fins whose lower edge borders the open lower end of the tube coming into contact directly with the ground, said tube being provided at its periphery with 'openings allowing the injection of said fluid material at least on either side of each fin; and in that said fluid material is injected as and when said tube is inserted inside it under sufficient pressure to overcome the

force of penetration of the soil inside the tube resulting from driving, so that said fluid material flows outside the tube on either side of said fins.

According to a preferred embodiment, this method is characterized in that transverse elements are provided which are shaped as troughs, the base of which faces towards the ground, arranged at the base of the tube substantially perpendicular to the tube, in which troughs are housed. lower edge of a fin, thereby facilitating the flow and guiding of said fluid material along the fins and at a distance from the tube.

According to a preferred embodiment, a non-return valve is provided inside said tube, preferably towards its base making it possible to limit the penetration of the earth from the ground inside the tube.

According to another preferred characteristic, the section of the fins is constant over most of their length.

According to another characteristic, a cylindrical envelope can be provided around the fins, which is preferably welded to the longitudinal edges of the fins, thereby further stiffening the structure.

According to another characteristic, the fins are shaped as light half-beams, preferably with a T-section.

The present invention relates, according to a second aspect, also to a driving tube as defined above, that is to say characterized in that it comprises a hollow tube open at least at its lower driving end, externally and longitudinally provided with at least two fins, the lower edge of which borders on the open lower end of the tube intended to come into direct contact with the ground, said tube being provided at its periphery with openings allowing the injection of a material fluid at least on either side of each fin.

Likewise, preferably, transverse elements shaped as a trough, the base of which is arranged closest to the lower end of the tube, are fixed substantially perpendicular to the tube in the vicinity of its base, the lower edge of a fin coming from lodge inside a corresponding trough, thus facilitating the flow and guiding of the material along the fins and away from the tube.

Also, it is possible to arrange, and preferably fix, a cylindrical envelope around said fins, thereby further stiffening the structure.

Also, preferably, the fins have a constant section over most of their length.

Also, the fins can be shaped into light half-beams, preferably with a T-section.

Finally, the tube is also preferably provided inside a non-return valve.

The previously announced technical advantages are thus obtained, namely a low resistance to penetration of the tube and a better intimate mixture between the soil and the injected curable fluid material, for example constituted by mortar or a curable synthetic resin.

Furthermore, preferably the height of the fins is two to three times the diameter of the lower end of the tube, and usually this height will be 30 to 60 cm.

On the other hand, the fins cut out the ground when driving in. In addition, the friction forces are reduced by the flow of the fluid material covering the tube and the fins during sinking.

Finally, after hardening of the curable fluid material, as indicated above, the soil, intimately mixed with the hardened material, such as concrete, is locked between the fins and the tube by increasing the bearing capacity of the pile thus formed. Typically, the width of the fins will be such that the maximum wheelbase will be three times the diameter of the tube.

• - la figure 1 représente un premier mode de réalisation d'un tube ou pieu'de fonçage selon l'invention pourvu d'ailettes;
• - la figure la représente une vue en coupe selon la ligne de trace I-I de la figure 1;
• - la figure 2 représente un deuxième mode de réalisation d'un tube ou pieu de fonçage selon l'invention;
• - La figure 2a représente une vue en coupe selon la ligne de trace II-II de la figure 2;
• - la figure 3 représente encore un autre mode de réalisation d'un tube ou pieu de fonçage selon l'invention;
• - la figure 3a représente une vue en coupe selon la ligne de trace III-III de la figure 3; et
• - la figure 4 représente une vue en coupe partielle d'encore un mode de réalisation d'un tube ou pieu de fonçage selon l'invention pourvu d'un clapet anti-retour.

Other characteristics and advantages of the invention will appear in the light of the explanatory description which follows, given with reference to the appended drawings in which:

• - Figure 1 shows a first embodiment of a driving tube or pile according to the invention provided with fins;
• - Figure la shows a sectional view along the trace line II of Figure 1;
• - Figure 2 shows a second embodiment of a driving tube or pile according to the invention;
• - Figure 2a shows a sectional view along the trace line II-II of Figure 2;
• - Figure 3 shows yet another embodiment of a driving tube or pile according to the invention;
• - Figure 3a shows a sectional view along the trace line III-III of Figure 3; and
• - Figure 4 shows a partial sectional view of another embodiment of a driving tube or pile according to the invention provided with a non-return valve.

With reference to FIGS. 1 and 1a, according to a first embodiment of a sinking tube or pile according to the invention, designated by the general reference number 1, said tube is hollow and is open at least at its lower end. for driving by presenting an opening 2. According to the embodiment shown, it can be seen that the tube 1 is provided externally and longitudinally with at least two fins 4, and here four fins arranged at 90 °, the lower edge of which is close to 4a. the lower open end of the tube 1 which is intended to come into direct contact with the ground.

According to the invention, said tube 1 is advantageously provided at its periphery with openings 6 cut in the mass of the tube in the vicinity of its lower end 1a so as to allow the injection of a curable fluid material such as for example mortar or a curable synthetic resin, at least on each side of each fin 4.

In other words, the openings 6 can be made beforehand by cutting at the lower end 1a of the tube 1 and then the fins 4 will be fixed, for example by welding, so that their plane is substantially parallel to a plane of symmetry passing by a diameter of the tube, as clearly visible in Figure la, the fin being substantially arranged in the center or symmetrically relative to the opening 6 and with its lower edge 4a in the vicinity of the lower end la. Here, the fins 4 are flush with the lower end of the tube 1.

On the other hand, and as can be seen in FIGS. 1 and 1a, the section of the fins 4 is constant over most of their length, this section being decreasing towards the tube only at the end and being able to end at a some distance from the edge of the tube, as shown, so as not to end the fin at a point.

Preferably, the height of the fins is 2 to 3 times the diameter of the tube, in particular in the vicinity of its lower end. On the other hand, preferably, the width of the fins is such that the total wheelbase of the tube 1 with the fins 4 is at most three times the diameter of the tube.

Thus, during driving, the resistance to sinking is reduced. This resistance to penetration is all the more reduced as curable fluid material, such as a mortar or a curable synthetic resin is injected under pressure inside the tube for example by a bypass 10 and flows out. outside along the tube 6 and on either side of the fins 4 through the openings 6.

Thus, after hardening, taking into account the constant injection of the curable fluid material during sinking, a pile having a total diameter at most three times the diameter of the tube is obtained; so, about twice the diameter, the ground is locked between the fins 4 and intimately mixed with the cured injected material, such as concrete or a cured synthetic resin.

The realization of such a pile is particularly suitable when there are limited working heights and when working in soft soil.

With reference to FIGS. 2 and 2a representing an alternative embodiment of the embodiment of FIG. 1, the same reference number has been used for the identical parts.

It can here be observed that the only difference with respect to the embodiment of FIG. 1 lies in the fact that transverse elements 12 are also provided, shaped as a trough, the base of which is arranged closer to the end of the tube 1, that is to say facing the ground. In addition, these trough elements are preferably arranged substantially perpendicular to the tube as clearly visible in Figure 2a. Also, these trough elements 12 are arranged so that the lower edge 4a of a fin 4 is housed inside the trough, preferably substantially in the middle of the latter as clearly visible in the figure. 2a.

It is thus understood that during the insertion of the tube 1 into the ground, the curable fluid material will have an easy flow and guidance along the fins 4 and at a distance from the tube 1 so as to ensure an intimate mixing of this curable fluid material. over the entire dimension of the fin. Thus, the width of the trough 12 is at least equal to the width of the opening 6. On the other hand, the resistance to sinking will only be slightly increased by the presence of these transverse elements in the shape of a trough. All the advantages of the first embodiment of FIG. 1 are thus obtained with the additional advantage indicated above of a distribution of the curable fluid material over the entire transverse dimension or width of the fins 4.

With reference to FIGS. 3 and 3a, an alternative embodiment of the embodiment of FIG. 1 is shown for which the same reference numbers have been used for the identical parts. It can also be seen that, according to this variant, a cylindrical envelope 14 is provided around the fins 4. This cylindrical envelope is preferably welded to the fins 4, this making it possible to stiffen the device and limit the torsional forces exerted on the fins 4 .

It will be noted, as can be seen in FIG. 4, that a slight annular rim 16 may preferably be provided at the base of the cylindrical envelope 14 so as to minimize the forces exerted on the welding of the cylindrical envelope on the fins 4.

On the other hand, this rim 16 being of a limited dimension, the resistance to penetration will only be slightly modified compared to the first embodiment of FIG. 1.

On the other hand, and as can be seen in Figure 1, the fins can be shaped into light half-beams, preferably with a T-section.

Finally, with reference to FIG. 4, the driving tube can be provided inside with a non-return valve 18 formed here by the combination of a flat element 20 here substantially circular provided in its center with an opening 22 which can be closed by a closure element 24 held captive and guided by an inverted conical element 26 provided with suitable openings 28 for the correct passage of the curable fluid material.

It is thus understood that this non-return valve 18 makes it possible to avoid the penetration of the ground inside the tube during the sinking of the latter.

Naturally, the invention is not limited to the embodiments described and shown which have been given only by way of examples. The invention therefore includes all the means constituting technical equivalents of the means described as well as their various combinations.

It will also be understood that the tube is preferably left permanently in the ground and is filled with hardened material, such as mortar or concrete made of synthetic resin, thus obtaining maximum bearing capacity even at shallow depths.

Claims (13)

1. Method for producing a pile of concrete or similar material, in the ground, comprising the insertion of a hollow tube (1), provided externally with fins (4), allowing the injection of a fluid material hardenable, for example a hardenable mortar or synthetic material, around said tube, as the tube is driven in, for example by beating, said tube being left permanently in the ground, characterized in that a hollow tube (1) open at least at its lower driving end (la), provided externally and longitudinally with at least two fins (4), whose lower edge (4) borders on the open lower end (2) of the tube coming into direct contact with the ground, said tube being provided at its periphery with openings (6) allowing the injection of said curable fluid material at least on either side of each fin (4), and in that said material is injected as the tube (1) is inserted inside said tube with u no pressure sufficient to overcome the force of penetration of the soil inside the tube (1) resulting from driving, so that the curable fluid material flows outside the tube (1) on either side of said fins (4). 2. Method according to claim 1, characterized in that provision is made for transverse elements (12) shaped as a trough, the base of which is arranged closest to the lower end (la) of the tube (1), arranged substantially perpendicularly relative to the tube, in which troughs (12) are housed the lower edge (4a) of a fin (4), facilitating the flow and guiding of the curable fluid material along the fins and at a distance from the tube . 3. Method according to claim 1 or 2, characterized in that there is a cylindrical envelope (14) around the fins (4). 4. Method according to one of claims 1 to 3, characterized in that the fins have a constant section over most of their length. 5. Method according to one of claims 1 to 4, characterized in that the fins are shaped as half-beams, preferably T-section. 6. Jacking tube for making a pile, characterized in that it comprises a hollow tube (1) open at least at its lower jacking end (la), provided externally and longitudinally with at least two fins (4) the lower edge (4a) of which borders on the open lower end (2) of the tube (1) coming into direct contact with the ground, said tube (1) being provided at its periphery with openings (6) allowing the injection of 'A fluid material curable at least on either side of each fin (4). 7. jacking tube according to claim 6, characterized in that it is provided with transverse elements (12) shaped as a trough, the base of which is disposed closer to the lower end (la) of the tube (1), and substantially perpendicular to the tube, in which troughs (12) are housed the lower edge (4a) of a fin (4). 8. Jacking tube according to claim 6 or 7, characterized in that the aforesaid fins (4) have a constant section over most of their length. 9. Jacking tube according to claim 7 or 8, characterized in that the fins (4) have a light half-beam shape, preferably with a T section. 10. Jacking pipe according to one of claims 6 to 9, characterized in that a cylindrical envelope (14) is arranged around the fins (4) being preferably fixed by welding thereto. 11. driving tube according to one of claims 6 to 10, characterized in that the length of the fins (4) is two to three times the diameter of the tube (1). 12. Driving tube according to one of claims 6 to 11, characterized in that the total wheelbase of the driving tube at the fins (4) is at most two to three times the diameter of the tube (1). 13. Jacking tube according to one of claims 6 to 12, characterized in that it comprises a non-return valve (18) inside the tube (1) in the vicinity of its lower part.

Images