BE1006194A5 - Drilling device and process for the formation of piles or the like - Google Patents

Abstract

The invention relates to a drilling device, including an active part (1)mainly consisting of a tube (6) around which is anchored a tubular helix (1)for insertion in the ground, said tubular helix being intended to be screwedin the ground during the drilling operation, while liquid passing throughsaid tube (6) and the helix (1) is simultaneously injected into the groundthrough holes (8) provided at least in one part of the lower end coil joiningsaid tube (6) in such a way that said injection liquid is mixed on the groundduring each rotation of the shaft (2) by the mashing action of the helix (1).<IMAGE>

Description

       

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  "Drilling device and methods for forming piles or the like".



   This invention relates essentially to a drilling device and methods for providing piles or similar anchoring structures.



   There is a known method of inserting an anchor tie into the ground described in document NL-8403178, and which consists in screwing into the ground a central rod comprising at its end. nity of insertion of a blade wound helically around said end, and at the end of the screwing operation, to inject a hardening liquid through orifices provided along said hollow rod.



   Such a method is also known from document NL-9000498 which describes a method for inserting or forming a stake in the ground, using a tool driven in rotation and pushed axially into the ground, said tool being equipped with a blade part in spiral, while a hardening pressurized liquid such as cement is injected through openings provided above and below the tool which is left in the ground to form a stake portion.



   Document NL-9000865 describes for example a method for inserting a foundation stake with an enlarged foot into the ground using a metal tube with a screw head at its lower end while a liquid, hardening or non-hardening such as water and / or bentonite is injected through an opening in the head forming the aforementioned screw. This liquid is mixed with the soil to form a mortar mixture with a support area around the pile.

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   However, in the first and second documents, the liquid is injected through holes provided in the wall of the central tube. As a result, said liquid is injected only in the center of the tool and not over the entire cutting surface of the helical tool. In addition, the method of the third document requires a very high driving power.



   The present invention eliminates these drawbacks by providing a drilling device and drilling methods to ensure homogeneous mixing of the soil with the liquid injected over the entire cutting surface of the tool by including reinforcement in the hardened soil zone.



   To this end, the subject of the present invention is a vertical drilling device for the formation of piles or the like, of the type comprising a rectilinear circular cylindrical tube which can be driven in rotation about its longitudinal axis and around which a cylindrical element is fixedly attached. hollow helical penetration intended to be screwed into the ground during drilling while a liquid, flowing in said hollow helical element, is simultaneously injected into the soil through outlet orifices provided in said helical element, characterized in that said tube with said helical element forms the lower portion and the only active part of the device, connected, possibly removably,

   to a rotational drive shaft and said helical element is a tubular propeller opening through its two opposite ends in said tube, between which ends said tubular propeller is spaced from said tube and said preferably radially external ejection orifices are located at least on a portion of the lower extreme turn joining said tube, said liquid passing through said tube.



   Thus, the injection liquid is mixed with the soil during each revolution of the shaft by the stirring effect of the propeller.



   According to a particular embodiment, said propeller is at least for the most part a cylindrical and circular propeller.



   According to a specific embodiment of the invention, said tubular helix is welded by its two opposite ends, or else near these two ends opposite to the aforementioned tube.



   According to a particular characteristic, substantially radial reinforcing bars are welded between the propeller and the tube.



   According to another characteristic of the invention, the lower part of said tube ends in a point.



   The aforementioned tube is closed at its base by a drill point plug and according to another particular characteristic of the invention, said drill point comprises liquid ejection orifices.

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   The aforementioned tip cap has a base plate which is preferably welded to the aforementioned tube.



   According to another particular characteristic, said injection orifices are protected by a material barrier preventing the introduction of soil into said propeller while allowing the passage of the liquid.



   It should be noted that the drive shaft can penetrate said tube and extend up to said base plate which comprises a stop element for positioning said drive shaft on said base plate of which it is integral.



   According to a particular characteristic, said drive shaft is an upper extension of the tube.



   According to a particular variant, said drive shaft is welded to the tube.



   According to another specific embodiment, said shaft is screwed onto said tube.



   According to another particular characteristic of the invention, said shaft consists of one of the elements chosen from the group comprising a steel tube, a steel profile, a solid steel rod, a concrete shaft.



   According to another particular characteristic, in the state buried in the ground, the aforementioned active part is uncouplable from the drive shaft.



   The present invention also relates to a method implemented by a drilling device comprising the preceding characteristics taken alone or in combination, this method being characterized in that after the drilling operation, the propeller, the tube and the shaft are left in the ground.



   The present invention also relates to a method characterized in that, when the active part can be uncoupled from said drive shaft, after the drilling operation, said shaft is filled with concrete so as to provide a concrete pile molded in said tree, and then the tree is extracted from the ground, while leaving said pile formed and the propeller in place.



   Another object of the present invention is to provide a drilling method implemented by a drilling device in which the active part can be disengaged from the part of the shaft and comprising the preceding characteristics taken alone or in combination

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 combination, said method consisting in that after the drilling operation, said shaft is filled with concrete so as to form a pile molded in said tree, and then the propeller and the shaft are extracted from the ground leaving said stake in place.



   Another object of the present invention is to provide a pile made with one of the preceding methods, and which can be provided with reinforcement.



   According to another characteristic, the wall of the tube comprises a concave or hollowed out part intended to improve the anchoring of the concrete pile when the propeller and the shaft are extracted.



   According to another embodiment of the invention, said drive shaft and said propeller tube consist of a single piece.



   According to a specific use of the drilling process, it is carried out in sandy soil and said injection liquid is laitance of cement.



   According to another use of the drilling method of the invention, it is implemented in a clay soil and said injection liquid is lime.



   According to another characteristic of the process according to the invention, the injection pressure is sufficient to prevent the soil materials or the earth from entering unprotected injection holes.



   However, other advantages and characteristics of the invention will appear better from the following description made with reference to the appended drawings given solely by way of examples and in which: - Figure 1 is a front and partial view, illustrating a first embodiment of the invention; - Figure 2 is a sectional and partial view, illustrating a second embodiment of the drilling device of the invention; - Figure 3 is a top view of Figure 2; - Figure 4 is a schematic view illustrating the drilling device of the invention operated to provide a pile with an enlarged tip; - Figure 5 is a schematic illustration of the injection orifices provided in the propeller;

   

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 - Figure 5a is a schematic bottom view of the propeller showing more particularly the injection holes protected separately; - Figure 5b "is a schematic sectional view along Vb-Vb of Figure 5a; and - Figure 5c is a similar view but illustrating a propeller protected by a continuous strip.



   FIG. 1 illustrates a drilling device according to an embodiment of the invention and comprising an active part A constituted by a tubular element in the form of a helix 1, opening by its two opposite ends 1a, 1b into a tube 6, to which tube 6 said ends 1a, 1b are tightly welded, said tube 2 or 6 and the propeller 1 also being welded on a drill point 3, the upper part of which comprises a base plate 4. It should be noted that said propeller 1 can be welded at its ends 1a and 1b to the tube 2.6 or else near these ends. The fixing of said propeller 1 to the tube 2 is obtained on the one hand by these ends la, lob of said propeller
1 and on the other hand, by means of reinforcing bars 5, extending radially between said propeller 1 and the tube 2 to which they are welded (5a).

   It is also visible in this figure, that an annular part 6a, the function of which will be described later, is welded around said tube 2.



   It should also be noted that in the case where the tube 2 is of a large diameter, a smaller tube can be placed in this same tube, so that the fluid is pumped through this smaller tube during drilling.



   According to a second embodiment illustrated in Figures 2 and
3, the drilling device of the invention comprises, on the one hand, the same elements as according to the first embodiment, that is to say, a tube 6 whose length is less than that of the previous embodiment, around which is welded a tubular propeller 1 with reinforcing bars 5 interposed between said propeller 1 and the tube 6, said tube 6 being welded to the base plate 4 of the reinforcing tip 3, and on the other hand, a shaft 2 , with a diameter less than the diameter of the tube 6, which is also welded by its lower end to the base plate 4 of the tip 3.

   We could also note in this figure, that a

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 stop element 7 is welded to the base plate 4 and is intended to ensure the positioning of the shaft 2 on the base plate.



   As will be more apparent from FIG. 5, said propeller 1 of the two embodiments, is provided with liquid injection orifices 8 on its lower turn before being folded towards the tube 6.



   These orifices 8 are covered with a material barrier 11 (FIG. 5a), allowing the liquid to flow while preventing the material from the ground from entering said propeller 1 (see FIG. 5b illustrating separate protection of the orifices and the Figure Sc illustrating continuous protection of the same orifices by a helical tube wound around the propeller).



   Alternatively, the injection pressure must be sufficient to prevent the soil materials or the earth from entering unprotected ejection orifices 8.



   The operation of the two embodiments of the drilling device according to the present invention will be briefly described through the following with reference to the drawings.



   During the drilling operation, the drilling device according to the first embodiment is screwed into the ground by the shaft 2 which is coupled to a drive mechanism, until the desired depth is obtained.



   During each revolution of said propeller in the ground, a hardening or non-hardening liquid, intended to reduce the resistance to drilling, coming from said tube 2 and flowing inside said tubular propeller is injected into the ground through the orifices 8 provided at the lower end of said propeller 1, so that said injection liquid can be mixed with the ground by the stirring action of said propeller 1 and to form an enlarged and reinforced tip if the liquid used is a liquid hardening.



   In this buried position of the drilling device, several methods can be envisaged for providing a pile.



   The first solution consists in leaving said tube 2 or else drive shaft 2, and the propeller 1 in the ground, while the second solution consists in extracting said tube 2 and the propeller 1 after filling said tube 2 for example , with reinforced concrete.

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   Thus, for example, in sandy soil, when injecting a hardening liquid into the bearing layer, a concrete pile P will be formed with an enlarged point 10 formed of cement, water and sand, such as described in Figure 4, said tip being used as a spiral reinforcement.



   It may also be noted that said annular abutment element 6a, mentioned above, during the extraction of the propeller 1, will allow a groove to be formed in the mortar (sand, cement and water), which groove will be filled with concrete, and will allow good adhesion to be obtained between the base of the pile obtained and the mass of the mortar.



   The operation of the drilling device of the second embodiment is similar to the first embodiment described, since said drive shaft 2 is welded to the tube 6 of the propeller 1.



   In the case, on the contrary, where the drive shaft 2 could be uncoupled from said tube 6, three possibilities could then be envisaged. In a first case, said tube 6, the shaft 2 and the propeller 1 are left in the ground. In the second case, only said tip 3, said propeller 1 and said tube 6 are left in the ground while said drive shaft 2 is extracted from the ground. According to this solution, said drive shaft 2 can be filled with concrete so as to form a concrete pile after extraction. It will be noted that said stake can be provided with reinforcement. In a third case, said propeller 1 fixed to the tube 6 and the drive shaft 2 are extracted from the ground, said shaft 2 being first filled, for example with reinforced concrete before extraction as described above for the first achievement.



   It will also be noted that the drilling device of the invention will preferably be used in sandy soil. The injection liquid will in this case be laitance of cement, and a mixture of cement, water and sand will be formed. Which mixture will harden in concrete providing some resistance to compression.



   On the contrary, if this drilling device is used in clay soil, a mixture of clay and lime can be formed, which after the hardening operation will also provide significant compressive strength.

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   It could also be envisaged, during the drilling operation, to change the injection liquid, for example first of all water and then of laitance of cement.



   Accordingly, it has been achieved by the invention, a drilling device with a spiral-shaped tip, to provide a pile with an enlarged base or blocks for anchoring structures, said invention making it possible to reduce the most possible the volume of soil that must be moved during drilling. There is thus obtained, during drilling, a homogeneous mixture of soil with the liquid on the total cutting surface of the device and a spiral reinforcement in the area of hardened soil.



   Of course, the invention is not limited to the embodiments illustrated and described.



   On the contrary, the invention includes all the equivalents of the means described, as well as their combinations if these are carried out according to the spirit.


    

Claims (24)

 CLAIMS 1. Vertical drilling device for forming piles (P) or the like, of the type comprising a straight circular cylindrical tube (6) (6) which can be driven in rotation about its longitudinal axis and around which an element is fixedly attached cylindrical helical hollow penetration (1) intended to be screwed into the ground during drilling while a liquid, flowing in said hollow helical element (1), is simultaneously injected into the soil through outlet orifices (8) formed in said helical element (1), characterized in that said tube (6) with said helical element (1) forms the only active part (A) of the device connected, optionally removably, to a shaft (2) for driving in rotation and said helical element (1)  is a tubular propeller opening through its two opposite ends (la, 1b) in said tube (6), between which ends said tubular propeller (1) is spaced from said tube (6) and said ejection orifices (8) preferably radially external are located at least on a portion of the lower extreme turn (lc) joining said tube (6), said liquid passing through said tube (6).  2. A drilling device according to claim 1, characterized in that the aforementioned propeller (1) is at least for the most part a cylindrical and circular propeller.  3. A drilling device according to claim 1 or 2, characterized in that said tubular propeller  <Desc / Clms Page number 10>  (1) is welded by its two opposite ends or near its two opposite ends (la, 1b) to said tube (6). 4. A drilling device according to any one of claims 1 to 3, characterized in that substantially radial reinforcing bars (5) are welded between the propeller (1) and the tube (6). 5. A drilling device according to any one of the preceding claims, characterized in that the lower end of the aforementioned tube (6) ends in a point. 6. A drilling device according to claim 5, with the aforementioned tube (6) closed at its base by a plug with a drilling point (3), characterized in that said drilling point (3) has ejection orifices (8 ) some cash.  7. A drilling device according to claim 6, the tip plug (3) comprises a base plate (4), characterized in that said plate is welded to the aforementioned tube (6).  8. A drilling device according to one of the preceding claims, characterized in that the aforementioned ejection orifices (8) are protected by a material barrier (11) preventing the introduction of soil while allowing the passage of the liquid.  9. A drilling device according to claim 7 or 8, characterized in that said drive shaft enters said tube (6) and extends to the aforementioned base plate (4) which includes a stop  <Desc / Clms Page number 11>  (7) for positioning said shaft (2) on said base plate (4) of which it is integral. 10. A drilling device according to one of claims 1 to 9, characterized in that said drive shaft (2) is an upper extension of said tube (6).   11. A drilling device according to any one of the preceding claims, characterized in that said drive shaft (2) is welded to the tube (6). 12. A drilling device according to one of claims 1 to 10, characterized in that said shaft (2) is screwed onto said tube (6).  13. A drilling device according to any one of the preceding claims, characterized in that the shaft (2) consists of one of the elements selected from the group comprising a steel tube, a steel profile, a rod full of steel, a concrete tree.  14. A drilling device according to any one of the preceding claims, characterized in that in the state buried in the ground, the active part (A) is uncouplable from the drive shaft (2).  15. A drilling method implemented by a device according to one of claims 1 to 14, characterized in that after the drilling operation, the propeller (1), the tube (6) and the shaft d 'drive (2) are left in the ground.  <Desc / Clms Page number 12>   16. A drilling method implemented by a device according to claim 14, characterized in that after the drilling operation, said shaft (2) is filled with concrete so as to provide a  EMI12.1  concrete pile molded in said shaft (2), and t the tree (2) is then extracted from the ground, while leaving said formed pile and the propeller (1) in place. 17. A drilling method implemented by a device according to claim 14, characterized in that after the drilling operation, said shaft (2) is filled with concrete so as to provide a concrete pile molded in said tree (2), and then the shaft (2) and the propeller are extracted from the ground, leaving said stake in place. 18. Pile, characterized in that it is produced by the method according to one of claims 15 to 17. 19. Pile, characterized in that it is produced by the method according to one of claims 15 to 17 and in that it is provided with a reinforcement. 20. A drilling device for implementing the method according to claim 17, characterized in that the wall of the tube (2) comprises a recessed or concave part (6a), intended to improve the anchoring of said concrete pile.  21. A drilling device according to one of claims 1 to 13, characterized in that the drive shaft (2) and the tube (6) of the propeller (1) are in one piece made of material.  <Desc / Clms Page number 13>   22. A drilling method according to one of claims 15,16 and 17, characterized in that it is implemented in sandy soil and in that the injection liquid is laitance cement. 23. A drilling method according to one of claims 15,16 and 17, characterized in that it is implemented in a clay soil and in that the injection liquid is lime. 24. A drilling method according to one of claims 15 to 17,22, 23, characterized in that the injection pressure is sufficient to prevent the soil or earth materials from entering unprotected ejection orifices .