EP1630299A1 - Method for strengthening a foundation and driiling tool therefor - Google Patents

Abstract

Method for sinking a foundation comprises passing the foundation into a borehole with a first small diameter and deep mortaring with a second larger diameter below the foundation. An independent claim is also included for a drilling and mixing tool for carrying out the above method. Preferred Features: Deep mortaring is carried out with a diameter which can be varied in height and is started by pulling the drilling and mixing tool.

Description

The invention relates to a method for searching under foundations in the form of floor panels, single or strip foundations. The starting point of such processes are subsidence phenomena on already completed structures, which must be compensated.

The invention further relates to a drilling and mixing tool in conjunction with a rotationally drivable drill string, wherein the drilling and mixing tool comprises a coaxial with the drill string aligned central part and at least two individually on the central part beiklappbar movably arranged folding cutters.

From DE 197 26 240 C1 a method for undertaking a standing in groundwater structure is known, in which a borehole is sunk by breaking the building soil in the ground below the building and produced by means of a Bodenbearbeitungsgeräges like a Injektionsdüsenträgers a soil composite column of suspension and soil whose diameter is larger than that of the borehole. The diameter of the harrow remains unchanged.

From DE 43 19 239 A1 a method for the Nachgründung supporting structural parts, in particular of floor slabs is known in which a bore is created by the building part, wherein subsequently a foundation bore is drilled with a head extension to form a foundation element. Here, the overburden of the head extension is removed from the borehole first. To form the borehole in the area of the head extension is a Aufschwenkbohrwerkzeug used, which comprises a cylindrical drill body and two Aufschwenkarme.

From DE 37 28 270 A1 a method for the production of concrete piles in the ground is known, in which first a drilled hole of smaller diameter than the pile diameter and drilled the well before pressing out of concrete from the bottom hole in the backward direction to a larger diameter becomes. A corresponding drilling tool comprises an inner drill string and an outer drill string with radially ausstellbaren cutting bodies, which have at the back to the hole opening towards cutting members. An expandable separating screen serves to separate a rinsing zone, from which the cuttings are carried away, from an injection zone, which is filled with concrete.

From US 4,701,078 a drill string with a drill bit at the bottom is known, which has cutting above the drill bit, which can be applied to the drill string and can be spread by the drill string via an actuated by pulling rope outer sliding sleeve. This device serves to create in the course of the production of an in-situ concrete pile underground a cavity enlarged in relation to a borehole into which concrete is later to be supplied via a pouring pipe for forming an enlarged pile foot.

Notwithstanding this, the present invention has for its object to provide a method for securing the foundation of the type mentioned.

• das Fundament in einem Bohrloch mit einem ersten kleineren Durchmesser durchfahren wird,und
• unterhalb des Fundaments eine tiefe Bodenvermörtelung mit zumindest einem zweiten größeren Durchmesser stattfindet.

The solution consists in a method of searching for foundations, in which

• the foundation is traversed in a borehole having a first smaller diameter, and
• below the foundation a deep Bodenvermörtelung takes place with at least a second larger diameter.

In this case, it is provided in particular, the subsequent process steps together with a drill and mixing tool attached to a drill string without performing intermediate pulling of the drill string. Here, after drilling through the foundation, the drilling and mixing tool used is increased in diameter, with a binder is fed and mortared with the ground. This causes a subsequent foundation of the foundation, which can serve to increase the carrying capacity or the settlement of settlement phenomena. The process can be distributed on individual foundations distributed according to a grid. The said at least one larger diameter in the area of Bodenvermörtelung can be adjusted as needed. It can also be varied by the height of the mortar column.

Alternatively, the deep Bodenvermörtelung can already be started at the first drilling of the drilling and mixing tool and, if necessary, continue with its drawing or only when pulling the drilling and mixing tool after the sinking to the lowest point can be started.

Furthermore, the present invention has for its object to provide a drilling and mixing tool that can be used in the aforementioned method.

The solution to this consists in a drilling and mixing tool in conjunction with a rotating drivable drill string, the drilling and mixing tool comprises a coaxial with the drill string aligned central part and at least two individual on the central part beiklappbar movably arranged folding cutters which are beiklappbar to the central part, wherein the folding blades are hinged and fixable to different diameters, and wherein outlet nozzles are provided on the drilling and mixing tool, which are supplied via the drill pipe with liquid medium. The adjustment to different diameters can be constructive designed as a continuous adjustment or as adjustment in individual stages. As liquid medium, water can be used during the drilling process with the folding flaps folded in, while after unfolding the folding cutters to the desired diameter, it is possible instead to supply binders in order to bring about soil softening.

This is a drilling and mixing tool given, which can be brought by means of said actuating means in a first position with a small diameter, for example, to pass through solid cover layers or foundations with a small diameter, and can be adjusted in stages or continuously to larger diameter, to prepare under it enlarged-diameter soil improvement areas with mixing of the soil with supplied suspension. In a particularly advantageous embodiment in this case the folding cutters are formed so that they comprise transverse to the longitudinal axis of the drill string pivot axes. This allows for an improved storage and support, on the other hand higher specific cutting forces on the folding blades for a given torque of the drill string. In a favorable embodiment, the folding cutters at their front edge in the direction of rotation considered tooth elements, which may consist in particular of hard materials.

Preferably, two folding cutters are provided, each of which can be actuated by steering levers and of these, wherein these steering levers lie in two different planes and move in these, so that they can cross over in side view. An actuating rod for the folding cutters or the steering levers can be arranged longitudinally movable in the drill string. On the steering arms, which are attached rigidly and at an angle to the folding cutters, handlebar arms can act, which are articulated on the one hand with the operating rod and on the other hand with the steering levers. The folding cutters can each form an angle of attack to radial or conical planes of rotation, in the sense that they cause a screwing into the ground when sinking in the unfolded state. The angle of attack can amount to about 30 ° with respect to a radial plane to the longitudinal axis of the drill string in a right angle unfolded state. In particular, the flap cutters have a large width in relation to their thickness, both of which are respectively constant over the length. In a preferred embodiment lying the folding cutters concealed in the folded position behind fixed parts of the central part and thus protected.

It is further proposed that the outlet nozzle for liquid medium at the central part of the mixing tool are each arranged centrally in the circumferential direction between the folding cutters. Hereby, the exit is in less the folding blades disturbed floor areas. For the rest, this does not hinder the escape of liquid medium when folded folding cutters. According to a further preferred embodiment, the outlet nozzle for liquid medium can be arranged above the articulation of the folding cutters and / or below the articulation of the folding cutters. This makes it possible that, depending on the process control and direction of movement of the mixing tool, the outlet of drilling fluid follows the folding blades and / or the outlet of binder suspension leads the folding blades.

• am Mischwerkzeug ist unten eine Bohrkrone befestigt,
• zwischen Mischwerkzeug und Bohrkrone ist ein Aufreibelement angeordnet.

According to further advantageous embodiments, the following features are proposed for the drilling and mixing tool according to the invention:

• a drill bit is attached to the mixing tool at the bottom,
• between mixing tool and drill bit a Aufreibelement is arranged.

• die Betätigungsstange für die Klappschwerter ist im Bohrgestänge angeordnet und wird von Hydraulikzylindern betätigt, die sich auf einer Konsole am oberen Ende des Bohrgestänges abstützen,
• die Konsole ist mit einem Wirbel verbunden, an dem das Bohrgestänge aufgehängt ist,
• das Bohrgestänge ist durch einen Durchsteckdrehkopf geführt und wird über diesen angetrieben,
• das Bohrgestänge besteht aus zwei ineinanderliegenden Rohrsträngen, durch die flüssiges Medium zwei verschiedenen Gruppen von Austrittsdüsen im Bohr- und Mischwerkzeug und/oder in der Bohrkrone geführt werden kann.

For the associated drill pipe, the following features for the design of the tool are mentioned:

• the operating rod for the folding swords is arranged in the drill string and is actuated by hydraulic cylinders, which are supported on a console at the upper end of the drill string,
• the console is connected to a swivel on which the drill pipe is hung,
• the drill string is passed through a turret and driven over it,
• the drill string consists of two nested strands through which liquid medium can be passed through two different groups of discharge nozzles in the drilling and mixing tool and / or in the drill bit.

• Figur 1 zeigt ein erfindungsgemäßes Bohrgestänge an einer Bohrlafette im Einsatz
  • a) in Seitenansicht,
  • b) in Stimansicht;
• Figur 2 zeigt das Bohrgestänge nach Figur 1 in vergrößerter Einzelheit;
• Figur 3 zeigt wesentliche Teile des Bohrgestänges nach Figur 2 in vergrößerter Darstellung
  • a) in Seitenansicht,
  • b) in Draufsicht;
• Figur 4 zeigt die Teile des Bohrgestänges nach Figur 3
  • a) im Vertikalschnitt,
  • b) in Draufsicht;
• Figur 5 zeigt die Durchführung des erfindungsgemäßen Verfahrens an einer Fundamentplatte;
• Figur 6 zeigt die Durchführung des erfindungsgemäßen Verfahrens an einem Gebäude.

A preferred embodiment of the invention is illustrated in the drawings and will be described below.

• FIG. 1 shows a drill pipe according to the invention on a drill mount in use
  • a) in side view,
  • b) in voice view;
• FIG. 2 shows the drill pipe according to FIG. 1 in enlarged detail;
• FIG. 3 shows essential parts of the drill string according to FIG. 2 in an enlarged view
  • a) in side view,
  • b) in plan view;
• FIG. 4 shows the parts of the drill string according to FIG. 3
  • a) in vertical section,
  • b) in plan view;
• FIG. 5 shows the implementation of the method according to the invention on a foundation plate;
• FIG. 6 shows the implementation of the method according to the invention on a building.

The two illustrations of FIG. 1 will be described together below. On a bottom surface 11 is a drill 12 to which a drill mount 13 is attached. On the drill mount 13, a drill string 15 is attached via guide means 14a, 14b. The drill pipe 15 is guided by a push-through turret 16 and with a tensioning device 17 rotatably clamped driven. The drill pipe 15 is rotatably suspended from a vortex 18. From the drill pipe 15 led out centrally is an actuating rod 21 which rotates with the drill pipe and is suspended on a further vortex 22. The actuating rod 21 is actuated axially via hydraulic cylinders 23, which are supported on a bracket 24 and act on a yoke 25. At the lower end of the drill pipe 15 is an inventive mixing tool 20 with a central portion 26 and radially projecting folding blades 27. At the lower end of the mixing tool 20, a drill bit 28 is attached.

In Figure 2, the drill string 15 is recognizable as an enlarged detail, with the same details are designated by like numerals as in Figure 1. The drill string consists of an outer tube 15 ₁ and an inner tube 15 ₂ , which are held by not shown spacers coaxial with each other. In the annular space between outer tube and inner tube on the one hand and in the inner cross section of the inner tube on the other hand, various media can be passed from the upper end to outlet nozzles at the lower end of the drill string. Of these, first and second outlet nozzles 31 ₁ , 31 _{2 can be seen} on the mixing tool 20 above and below the articulation of the folding cutters 27 and further outlet nozzles 32 on the drill bit 28. Between the mixing tool 20 and the drill bit 28, a friction disk 29 is arranged.

At the mixing tool 20, the continuously adjustable diameter of the folding blades 27 ₁ , 27 _{2 can be seen} . At the upper end of the drill string 15, the through-boring head 16 with clamping device 17 and the vortex arrangement 18 can be seen. The pull rod and its actuating means are not shown here.

In Figure 3, the individual representations are described together below. In detail, the mixing tool 20 with the central part 26 and the adjustable folding cutters 27 ₁ , 27 _{2 will first be} described, the latter being shown in their various possible positions. The mixing tool according to illustration b) is to be understood as dextrorotatory, wherein cutting edges 33 ₁ , 33 ₂ on the folding cutters 27 ₁ , 27 _{2 are} equipped with teeth. The folding cutters can be set so that they screw in a twisting drive of the mixing tool downwards into the ground. On the mixing tool 20, furthermore, the first and second outlet nozzles 31 ₁ , 31 _{2 can be seen} . The mixing tool 20 is attached to the drill pipe 15. Of the actuating means for the folding cutters 27 ₁ , 27 ₂ , the console 24 and the hydraulic cylinders 23 ₁ , 23 _{2 can be seen} , which act on the yoke 25 and the angle 22 on the actuating rod 21. Furthermore, the vortex 18 for the drill string 15 can be seen. For this, a channel 34 is led out to supply the linkage 15 with liquid medium.

In Figure 4, the same details as in Figure 3 are provided with the same Bezugsziffem. In the sectional view are still in two positions steering lever 35 ₁ , 35 ₂ for the folding cutters 27 ₁ , 27 ₂ can be seen, which are rigidly connected to the latter. In this steering lever 35 ₁ , 35 ₂ act on the control arms 36 ₁ , 36 ₂ , which are each connected to the lower end of the actuating rod 21 via a hinge point 37 and the steering levers 35 ₁ , 35 ₂ via hinge points 38 ₁ , 38 ₂ . Since the steering levers 35 ₁ , 35 ₂ cross over, they pivot in different levels.

FIG. 5 shows a method according to the invention for grounding a foundation in three phases.

Illustration a) shows a foundation plate 41, under the grown bottom 43 is located. A drilling apparatus comprising a drill string 15, a reduced diameter mixing tool 20 and a drill bit 28 penetrate the foundation plate 41.

In illustration b), the foundation plate 41 is penetrated by a bore 44, wherein the mixing tool has reached its lowest position. After passing through the foundation plate 41, the folding blades 27 of the mixing tool 20 are unfolded, so that the diameter of the mixing tool is now larger than that of the bore 44, and the mixing tool 20 rotates in particular with rotating drive automatically down into the ground.

In illustration c), the mixing tool 20 described above is now pulled up with the application of binder suspension, wherein a Vermörtelungskörper 45 is produced with respect to the bore 44 in the base plate 41 larger diameter, which forms an additional foundation for the foundation plate 41. The still rotating driven mixing tool 20 hereby mixes the binding agent suspension with the already loosened soil. Shortly before reaching the foundation plate, the mixing tool 20 is brought back into the state as shown in illustration a), so that it can be returned through the bore 44.

FIG. 6 shows a method according to the invention for undertaking a building foundation. It is a foundation 41 'with an upstanding wall 42 to recognize, under the foundation 41 grown bottom 43 is located. The foundation 41 'is designed as a strip foundation under a bottom plate 41, which can continue to the right. A drilling apparatus comprising a drill string 15, a reduced diameter mixing tool 20, and a drill bit 28 penetrate the foundation 41 'outside the wall 42.

In illustration b), the foundation 41 'is penetrated by a bore 44, wherein the mixing tool 20 has reached its lowest position. After passing through the foundation 41 ', the folding blades 27 of the mixing tool 20 are unfolded, so that the diameter of the mixing tool is now larger than that of the bore 44 and the mixing tool 20 rotates automatically with rotating drive in particular automatically into the ground.

In illustration c), the mixing tool 20 described above is now pulled up with the application of binder suspension, wherein a Vermörtelungskörper 45 is produced with respect to the bore 44 in the foundation 41 'larger diameter, which forms a lateral underpinning for the foundation 41' at the edge of the building , In this case, the mixing tool 20 driven in rotation thereby mixes the binder suspension with the previously previously loosened base. Shortly before reaching the foundation, the mixing tool 20 is brought back into the state as shown in illustration a), so that it can be returned through the bore 44.

LIST OF REFERENCE NUMBERS

11

ground

12

caterpillar

13

gun carriage

14

guide

15

drill pipe

16

Rotary union

17

chuck

18

whirl

19

20

mixing tool

21

pull bar

22

whirl

23

hydraulic cylinders

24

console

25

yoke

26

Central part

27

cutting element

28

drill bit

29

reamer

30

31

jet

32

jet

33

cutting edge

34

feed

35

control arm

36

handlebar lever

37

fulcrum

41

foundation

42

wall

43

ground

44

drilling

45

Vermörtelungssäule

Claims (22)

Method for the examination of foundations (41), in which - The foundation (41) in a borehole (44) is passed through with a first smaller diameter, and - Underneath the foundation (41) a deep Bodenvermörtelung (45) takes place with at least a second larger diameter. Method according to claim 1,
characterized,
in that the method steps are subsequently performed with a drilling and mixing tool attached to a drill pipe without intermediate pulling of the drill string. Method according to one of claims 1 or 2,
characterized,
that the deep Bodenvermörtelung takes place with a variable over the height diameter. Method according to one of claims 1 to 3,
characterized,
that the deep Bodenvermörtelung the first drilling of the drilling and mixing tool is started. Method according to one of claims 1 to 3,
characterized,
that the deep Bodenvermörtelung is started when pulling the drilling and mixing tool. Drilling and mixing tool (20) in conjunction with a rotationally drivable drill pipe (15), wherein the drilling and mixing tool (20) coaxially aligned with the drill string central part (26) and at least two individually on the central part beiklappbar movably arranged folding cutters (27) includes, which are beiklappbar to the inner part,
characterized,
in that the folding cutters (27) can be opened to different diameters, and that outlet nozzles (31, 32) are provided on the drilling and mixing tool (20), which are supplied with liquid medium via the drill pipe (15). Tool according to claim 6,
characterized,
that the folding blades (27) are adjustable and fixable at continuously variable diameter. Tool according to one of claims 6 or 7,
characterized,
in that the folding cutters (27) are arranged such that they can be folded around transversely to a longitudinal axis of the drill rod (15) extending pivot axes. Tool according to one of claims 6 to 8,
characterized,
in that two folding cutters (27) are provided which are each connected to steering levers (35) which lie in two different planes and can cross each other. Tool according to claim 9,
characterized,
in that an actuating rod (21) for the folding cutters (27) is arranged longitudinally in the drill pipe (15). Tool according to claim 10,
characterized,
that on the steering lever (35) link arms (36) act, which are connected via a first hinge point (37) with the lower end of an actuating rod (21) and via second hinge points (38) with the steering levers (35). Tool according to one of claims 6 to 11.
characterized,
in that a drill bit (28) is fastened to the bottom of the drilling and mixing tool (20). Tool according to claim 12,
characterized,
a mixing element (29) is arranged between the mixing tool (20) and the drill bit (28). Tool according to one of claims 10 to 13,
characterized,
in that the actuation rod (21) for the folding cutters (27) in the drill string (15) is actuated by hydraulic cylinders (23) which rest on a bracket (24) at the upper end of the drill string (15). Tool according to claim 14,
characterized,
in that the bracket (24) is connected to a swivel (18) on which the drill string (15) is suspended. Tool according to one of claims 4 to 15,
characterized,
in that the drill pipe (15) is guided through a through boring head (16) and driven by it. Tool according to one of claims 4 to 16,
characterized,
that the drill pipe (15) consists of two nested pipe strands (15 ₁ , 15 ₂ ), through the liquid medium two different groups of outlet nozzles (31, 32) in the drilling and mixing tool (20) and / or in the drill bit (28) can be supplied, in particular a group for flushing medium and a group for binder suspension. Tool according to one of claims 6 to 17,
characterized,
that the folding cutters (27) are inclined to the direction of rotation and are provided in particular at their front in the direction of rotation edges with tooth elements. Tool according to one of claims 6 to 18,
characterized,
in that the folding cutters (27) have a large width in the circumferential direction of the drill pipe at a small thickness. Tool according to one of claims 6 to 19,
characterized,
in that the folding cutters (27) are concealed and protected behind fixed parts of the central part in the position folded in towards the central part in the circumferential direction of the drill string. Tool according to one of claims 6 to 20,
characterized,
that the outlet nozzles (31) are arranged for the liquid medium in the central part (26) of the mixing tool (20) in the circumferential direction between the tiltable cutters (27). Tool according to one of claims 6 to 21,
characterized,
that the outlet nozzle (31) for liquid medium above the articulation of the folding blades (27) and / or below the articulation of the folding blades (27).

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