TOOL WITH A BASE ELEMENT AND STUDS PROVIDED THEREON AND USE OF SUCH TOOL FOR FORMING SECANT WALLS

Abstract

The invention relates to a tool (11) comprising a base element (2), which is a single-piece cast structure made of cast iron and comprising studs (3, 4) provided on the base element (2) by welding. The invention further relates to a method for forming such a tool and to the use of such a tool for forming secant walls.

Claims

1. Tool (11) comprising a base element (2) and studs (3, 4) provided on the base element (2), characterised in that the base element (2) is a single-piece cast structure made of cast iron, and in that the studs (3, 4) are provided on the base element (2) by welding.

2. Tool (11) according to claim 1, characterised in that the studs (3, 4) are made of a composition comprising tungsten and/or tungsten carbide.

3. Tool (11) according to claim 1, characterised in that the studs (3, 4) are provided on the base element (2) by spot welding.

4. Tool (11) according to claim 1, characterised in that the tool (11) is a drill tool.

5. Tool (11) according to claim 4, characterised in that the drill tool is a casing shoe (1).

6. Drill assembly (14) comprising: a drill pipe (7); and a tool (11), which tool (11) at a first end (8) is provided to be connected to an end (10) of the drill pipe (7) and at a distal end (9), opposite to the first end (8) is provided with studs (3, 4); characterised in that the tool (11) is a drill tool according to claim 4.

7. Method for forming a tool (11) according to claim 1, characterised in that the method comprises the following steps: a. casting of the base element (2) from cast iron as a single-piece cast structure; and b. welding of studs (3, 4) to the base element (2).

8. Method according to claim 7, characterised in that the base element (2) is provided with application surfaces (5, 6) for welding the studs (3, 4) to the application surfaces (5, 6) and in that between steps a and b, these application surfaces (5, 6) are finished for welding the studs (3, 4) to the application surfaces (5, 6).

9. Use of a tool in a drilling assembly according to claim 6, characterized in that a tool (11), which is a casing shoe (1) drill tool is used for forming secant walls.

10. Use of a tool according to claim 9, characterized in that the tool (11) is a casing shoe (1).

Description

[0028] In this detailed description, reference numerals are used to refer to the attached drawings, in which in:

[0029] FIG. 1 shows a casing shoe according to the invention in perspective view;

[0030] FIG. 2 shows a part of the casing shoe of FIG. 1 in more detail in perspective view at the height of some studs;

[0031] FIG. 3 shows the casing shoe of FIG. 1 in view according to arrow F3 in FIG. 1;

[0032] FIG. 4 shows the casing shoe of FIG. 1 in cross section, according to line AA in FIG. 3,

[0033] FIG. 5 schematically shows in perspective view an intermediate step of a method for forming a secant wall using a casing shoe according to FIG. 1, wherein two first bores are filled with concrete to form two first piles;

[0034] FIG. 6 schematically shows in perspective view how using a casing shoe according to FIG. 1, when a second bore is drilled, between and partially through the first piles;

[0035] FIG. 7 schematically shows in cross section how using a casing shoe according to FIG. 1, when a second bore is drilled, between and partially through the first piles.

[0036] The illustrated tool 11 is a casing shoe 1 for forming secant walls. In order to form the illustrated casing shoe 1, a base element 2 is cast from cast iron as a single-piece cast structure, preferably from ductile cast iron. The base element 2 is mainly cylindrical and is provided with ribs 15 at its outer circumference.

[0037] As best seen in FIGS. 4, 6 and 7, at a first end 8, the base element 2 is provided to be connected to an end 10 of a drill pipe 7. At this first end 8, an undercut 16 is therefore provided at the inner surface of the base element 2 via machining, e.g. via turning on a lathe. The drill pipe 7 is provided with a corresponding undercut 17 on its outer surface, for connecting the casing shoe 1 to the drill pipe 7.

[0038] Connection holes 12 are drilled along the contour of the base element 2 for inserting a coupling element 13 therein. The drill pipe 7 is provided with corresponding connection holes 18, for inserting the coupling element 13 therein, for connecting the casing shoe 1 to the drill pipe 7. Alternative coupling systems are also possible for connecting such a casing shoe 1 to such a drill pipe 7.

[0039] At a distal end 9 of the base element 2, opposite the first end 8, application surfaces 5, 6 are provided on the base element 2. After casting of the base element 2, these application surfaces 5, 6 are finished or machined, e.g. milled or grinded to finish these application surfaces 5, 6 for welding studs 3, 4 to the application surfaces 5, 6.

[0040] First application surfaces 5 are provided downward at the distal end 9 of the base element 2 and first studs 3 are welded to the first application surfaces 5, extending axially with respect to the base element 2. Second application surfaces 6 are provided sideways, facing under and angle with respect to the first application surfaces 5. Second studs 4 are welded to the second application surfaces 6, extending sideways (outward) facing under an angle with respect to the first studs 3. Possibly, further studs can be provided sideways (inwards) facing under an angle with respect to the first studs 3.

[0041] The studs 3, 4 of the illustrated casing shoe 1 are made of a composition comprising tungsten and/or tungsten carbide, but could also be made of any other suitable material. The studs 3, 4 are spot welded to base element 2 using a known welding machine for spot welding such studs 3, 4, by placing the studs 3, 4 with the welding machine on the corresponding application surfaces 5, 6 and applying a current with this welding machine. Alternative welding techniques are also possible to weld the studs 3, 4 to the cast iron base element 2.

[0042] With a diameter of approximately 430 mm, the illustrated casing shoe 1 can be loaded with a pushing force of approximately 20000 kg.

[0043] The illustrated casing shoe 1 is more specifically suitable for forming secant walls, as illustrated in FIGS. 5 to 7. The casing shoe 1 forms part of a drill assembly 14 comprising the drill pipe 7 to which the casing shoe 1 is connected. At a first end 8 the casing shoe 1 is provided to be connected to an end 10 of the drill pipe 7 and at a distal end 9, opposite to the first end 8 the casing shoe 1 is provided with studs 3, 4, so that the casing shoe 1 can be used as a drill tool.

[0044] First (odd) bores are in this respect drilled into a soil 19, by using any suitable drill tool according to the invention, e.g. by using the illustrated casing shoe 1, and concrete is poured in these first bores for forming first piles 20, as illustrated in FIG. 5. Preferably while the concrete of the first piles 20 is not fully cured, second (even) bores are drilled between the first piles 20, also using the casing shoe 1, as illustrated in FIGS. 6 to 7. In these second bores reinforcement elements are then added and concrete is poured in these second bores for forming second piles that form together with the first piles 20 a secant wall.

[0045] Similar to how the illustrated casing shoe 1 that comprises a base element 2 that is provided with studs 3, 4, one can also make a tool 11 such as a drill tool comprising a cast iron base element 2 such as a drill tip similar to the ones as illustrated in U.S. Ser. No. 10/683,630, U.S. D845737 and U.S. Ser. No. 10/640,946 provided with studs 3, 4 for drilling holes, or make a tool 11 comprising a cast iron drum with studs 3, 4 for machining material from a surface.

[0046] The illustrated studs 3, 4 can be known studs, e.g. used for being welded to steel. Alternatively to the illustrated studs 3, 4, such studs can also take many other forms or shapes, such as e.g. a form or shape as the protrusions illustrated in U.S. Ser. No. 10/683,630.