EP2080836B1 - Method for fixing soil sections and device for executing the method - Google Patents

Description

The invention relates to a method for consolidating bottom sections, in particular for lifting injections, wherein starting from spaced bores in connection with the introduction of injection media, a lifting injection, soil consolidation, fracture injection or Pipe screen injection, thereby first bores introduced into the soil and then via a multi-injectable injection tube an injection medium is pressed.

In the case of uplift injections, injection pipes (cuff pipes) that can be injection-molded several times under the building must be drilled beforehand, eg when passing through buildings with a tunnel. It is extremely important to avoid subsidence that no soil is withdrawn when drilling in the multi-compressible sleeve pipes. After introducing the multi-compressible sleeve pipes, the soil is pre-tempered with a hardening injection medium. Thereafter, the injection tubes are rinsed. If settling occurs during or after the tunneling, it is pressed again through the cuff pipes in order to raise the buildings again. Furthermore, with the method, a tunnel safety during propulsion can be produced by means of an injection tube screen, starting from the spaced bores in conjunction with a body formation taking place through an injection medium, creating a contiguous floor structure, initially introducing bores into the soil and subsequently by way of a multiple-compression process Injection tube an injection medium is pressed to form a body which overlaps with the body of the adjacent bore. In addition, the method is also applicable to fracture and Sohlinjektionen. Bodeninjektionen are necessary, inter alia, to the ground, z. B. to improve higher loads, seal the soil or fractures in the rock, buildings, such. B. in underrunning with tunneling to lift again, to raise existing structures or to secure by an underpinning, disturbed mountain areas with z. For example, to consolidate pipe screens to secure tunnel bores, or to construct excavation enclosures and excavation bottoms, see, for example, Document DE-C1-101683.1 ,

Furthermore, the invention relates to an apparatus for carrying out the method according to the invention.

Such a method, which is used for soils without pressurized water, is well known. The drilling of the hole is done in the overlay drilling method by an external drill pipe and an inner drill pipe are drilled with a double turret to the desired depth. The outer drill string includes a ring bit, while the inner drill string has a full drill bit that fits into the outer drill string. The inner bit is rebuilt with the Innenbohrgestänge after reaching the final depth, introduced a filling hose into the hole and this example, filled with a consisting of one of the cement suspension, acting as a jacket mixture binder. Due to the required large diameter drill, the soil can not be displaced, but must be carried away between the outer drill pipe and the inner drill pipe. Only the soil should be removed, which corresponds to the diameter of the hole. However, this is difficult to control because of the indispensable flushing of the hole slightly more soil is withdrawn. Due to the large soil withdrawal settlements occur. In addition, a correspondingly strong and large drill is needed for the large diameter drill. After installation of the jacket mixture, a multiple-compression injection tube (sleeve tube) made of steel or PVC is installed therein, the well mouth is closed and the ground consolidation serving injection medium is carried out by means of a packer on the rubber injection valves designed as a sleeve of the injection tube. For longer holes several pipe sections are time consuming glued or screwed together. There is a risk that the adhesive gets into the tube and then later in the actual injection can cause problems when installing the double packer. If the installation of the injection tubes is completed, the outer drill string is pulled. Here, too, it comes to subsidence, because the space of the pulled out of the ground outer drill pipe is not filled and thereby creates a cavity. This cavity is filled alone with Nachsackungen the surrounding soil.

Furthermore, a method is known, which is used for floors, where you have to work against oppressive water. Before drilling, a preventer with flat slide (seal, non-return valve) is mounted in a wall (bored pile, slot or sheet pile wall), so that no ground can be discharged next to the outer drill pipe due to the impending external water pressure. Then, in the overburden drilling method, an external drill string and an inner drill string are drilled to the desired depth with a double turret. Thus by the pending external water pressure is not constantly carried out between the inner drill pipe and outer drill pipe soil discharge, a drill bit on the inner drill pipe, which is larger than the outer drill pipe, mounted with a latch. The drill bit has a tapered sealing flange that is pulled into the conical shaped beginner tube of the outer drill string to avoid bottom pull during drilling. If the soil can no longer be displaced during drilling, the drill bit is pushed forward with the inner drill pipe to open the soil compacted in front of the drill bit, thus opening the annular gap between the drill bit of the inner drill pipe and the beginner pipe. The soil is then removed in the annular gap between the inner drill pipe and the outer drill pipe via an ejector bell or a relief valve on the preventer. However, this can not be controlled due to the external water pressure. If the drilling progress returns due to the soil removal, the drill bit is positioned again in the sealing cone of the beginner's tube. Once the required drilling depth has been reached, the inner drill pipe is pulled out of the drill bit (lost drill bit), a multiply compressible injection pipe (sleeve pipe) installed in its place, and the subsequent installation of the outer drill pipe simultaneously realized the installation of the casing mixture, which is a sheath of the injection pipe and sealing causes the hole and ensures that the individual stages (cuffs) of the injection tube have no connection with each other. The outer drill pipe thus serves at times as a protective tube for the injection pipe (sleeve tube).
Before pulling the last outer drill pipe from the seal (Preventer), the annular gap between, for example, the diaphragm wall and the injection pipe must be sealed. Finally, the closure of the wellbore mouth with sealing mortar or an end seal and the actual, the soil consolidation serving introduction of the injection medium carried out using a packer / twin packer on the designed as a rubber cuffs valves of the injection tube.

A disadvantage of this procedure is that stones can jam between the sealing surfaces, so that the advanced drill bit can not be resumed sealingly on the beginner tube. In this case, then takes place again a constant, subsidence after pulling soil withdrawal. If the soil (mountains), for example, gaps or cavities, the drill bit from the Klinkverschluss the Innenbohrgestänges can solve and fall off. Then the outer drill pipe is completely open and as soon as the turret is unscrewed from the outer drill pipe at the borehole mouth, the soil is penetrated by the whole cross section of the drill pipe External drill pipe removed. The hole must then be pressed and abandoned to avoid major damage. Another disadvantage is that the drill bit must be disengaged each time an extension tube section (attachment tube) is replaced, and it must be threaded again after the extension tube has been fitted. This is not only very time consuming, but it often comes to the above-mentioned problems when opening the seal between the beginner's tube and drill bit or even the Bohrkronenverlust. When removing the Innenbohrgestänges it is to be regarded as a disadvantage that when the drill bit does not effectively seal the interior of the outer drill pipe, in addition to the thus adjusting bottom removal, the interior of the outer drill pipe is filled with soil, so that the now required installation of the injection pipe is not can take place. In addition, when pulling the outer drill pipe, which also acts as a protective tube for the injection pipe, there is a risk that the sleeve tube is clamped by penetrating bottom between sleeve tube and outer drill pipe and entrained with the outer drill pipe, whereby the sleeve pipe is either destroyed and unusable or the subsequent , via the valves of the injection tube to be made introducing the injection medium can not be secured in the intended areas of the soil. This calls into question effective soil consolidation as a whole. Another disadvantage is that if the drill bit is not completely sealed, the jacket mixture can be rinsed out. Before pulling the last outer drill pipe from the preventer, the annular gap between, for example, the diaphragm wall and the injection pipe must also be temporarily sealed before the final sealing of the drill hole to prevent soil removal. This is time-consuming and costly and not always successful, so that it often comes to bottom withdrawal and resulting subsidence. Ultimately, a correspondingly powerful and large drilling rig is needed for the large diameter drill.

It is an object of the present invention, a method and a device of the type mentioned in terms of process optimization, especially when drilling against oppressive water, such further that with a reduction in the number of operations, small diameter drill and less powerful drill, without costly expansion of the outer drill pipe Before the injection a soil removal and thus settlements avoiding work is made possible, the installation of the injection tube (sleeve tube) fully secured and made by ensuring the position assurance for the injection tube targeted introduction of the injection medium in the soil and drilling under tight spatial conditions (in the area of tunnel boring machines, in tubes and basements or similar) can be ensured.

According to the invention this object is achieved in a generic method by the features of claim 1, wherein the contributing to the task solution device is apparent from the patent claim 6.

The advantages of the invention are that it can be dispensed with the installation of a separate injection tube and a required protective tube for the injection tube, since that outer drill pipe includes the beginner tube, which is firmly connected to the drill bit and at the same time designed as an injection tube and after reaching the End depth when drilling in the ground as a lost drill and injection tube remains or can be dismantled. It can be used immediately, only the inner rod has to be dismantled. Due to the small diameter of the outer drill pipe, where a self-contained protection pipe for the injection pipe is not required, drilling can be carried out in the displacement process and soil removal and resulting settlement can be avoided.
Due to the firm connection between the beginner's pipe and the drill bit, it is no longer necessary to readjust the drill bit with respect to the outer drill pipe and then retract it after placing the extension pipe so that unwanted soil removal in turn prevents premature loss of the drill bit and the associated task of drilling can be excluded. Due to the firm connection between the beginner's pipe and the drill bit, there is no danger that the drill bit will not adequately seal the interior of the outer drill pipe when it is being removed. The drill bit will fill with soil and initiate a soil removal. In addition, the flushing risk of the jacket mixture is prevented. Due to the fact that the outer drill pipe performs both the function of a drill pipe and an injection pipe at the same time, the otherwise required removal of the outer drill pipe prior to the injection can be dispensed with in the invention. Thus, associated subsidence for filling the space of the outer drill pipe can be prevented and a cavitation, which then filled with Nachsackungen the surrounding soil, can be excluded.
Depending on the type of soil consolidation (eg with gels), it is also possible to rebuild the injection tube after injection and reuse it. This is accompanied by a significant cost reduction and there are no hindrances to the ground that hinder future construction.

In summary, a method is provided which effectively eliminates soil deprivation and related settlements, manages with a low number of operations (2 instead of 5 steps) at low cost and short construction time, requires only a small, lower performing and cheaper drilling rig, and work under tight spatial conditions (eg in tunnels). In addition, lower construction site setup and storage costs can be realized.

Advantageous procedural developments of the invention are characterized in the claims 2 to 5.

Preferred device embodiments of the invention will become apparent from the claims 7 to 12.

The invention will be explained in more detail below using an exemplary embodiment and associated drawings.

Show it:

Fig. 1

a partially sectioned side view of the apparatus for performing the method according to the invention

Fig. 2

an enlarged sectional view of the injection tube in the side view

Fig. 3

a sectional view of the injection tube along the line A - A of Fig. 2

Fig. 4

a sectional side view of the already pre-cemented wall (Bohrpfahl-, slot or sheet pile wall) in which a preventer (seal, backflow preventer) has been positioned

Fig. 5

a sectional side view of the apparatus for performing the method according to the invention, wherein the drillable injection tube with the inner rod has reached the Endinbohrtiefe

Fig. 6

a sectional side view of the apparatus for performing the method according to the invention, wherein the inner rod has been removed from the injection tube already

Fig. 7

a sectional side view of the apparatus for performing the method according to the invention, wherein in the injection pipe, a double packer has been introduced for pressing the soil

The in the Fig. 1 and 2 shown device that is particularly advantageous when drilling against oppressive water use consists of individual to lengthen screwed together steel outer drill pipe 1, a coaxial with the outer drill pipe 1 provided inside linkage 2, wherein after Fig. 2 the first bottom-side outer drill pipe (beginner pipe) with a drill bit 3 by screwing or welding firmly connected and as a multi-compressible injection pipe (sleeve tube) 4 is executed. This injection tube 4 is provided in its longitudinal extension by way of example with three spaced-apart recesses 5 and a plurality of radially extending therein in the injection tube 4 openings 6, over which sealingly each an elastic sleeve 7 is arranged. The elastic sleeves 7 are embedded in the respective recess 5 on the injection tube 4 and outside partially covered by four fenders 8 so that advantageously formed by the fenders 8 around the elastic sleeves 7 diameter with the diameter of the injection pipe 4 / outer drill pipe 1 congruent is. To Fig. 3 are preferably in a recess 5 of the injection tube 4 four apertures 6 are arranged, which are opposite to each other in pairs and are positioned so that they are in the area under the elastic sleeve 7, which then not from the four, also pairwise opposite fenders 8 is covered. At an internal pressurization, the passages 6 act in conjunction with the associated elastic sleeve 7 as valves. Depending on the required drilling depth, the extension pipe 1 'adjoining the outer drill pipe 1, which is designed as an injection pipe 4, can also be designed as valve-carrying injection pipes (not shown). The drill bit 3 is injection tube side a bayonet closure 9 or a sleeve (not shown) for the coupling with the inner rod 2 and check valves 10 for the prevention of soil entry assigned. Drilling into the ground is carried out with a drilling rig 11 ( Fig.1 ).
Accordingly, the method for solidifying or pressing of soil sections elaborates such that when working against oppressive water 12 before drilling in the pre-potted wall 13 (bored pile, slot or sheet pile wall) a preventer 14 with flat slide (seal, non-return valve) is mounted ( Fig. 4 ), so that later by the pending Außenwasserüberdruck no bottom 15 can be discharged in addition to the outer drill pipe 1. Then done in the protection of the preventer 14, the coring of the wall 13. Subsequently, the installation of the steel, itself as a multi-injection tube injection 4 (sleeve tube) designed and bottom side equipped with a drill bit 3 beginners tube of the outer drill pipe 1, which directly into the ground 15th drilled to the final boring depth in the displacement method ( Fig. 5 ) and remains in the soil 15 as a lost drill and injection tube 4 with drill bit 3 or after the injections again dismantled and reused.
During drilling, the drilling fluid to be flushed into the soil via the inner rod 2 in conjunction with the holes in the drill bit 3, so that no pressure on the elastic sleeves 7 of the injection tube 4 is applied. Depending on the specific conditions, it is also possible, the shell mixture 16 directly when drilling or after reaching the Endinbohrtiefe on the inner rod 2 and the drill bit 3 in the annular gap of the bore, which is formed by the cutout of the drill bit 3, bring. Alternatively, the jacket mixture 16 can be pressed by means of pressurization on the cooperating with the elastic sleeve 7 openings 6 in the annular gap of the bore, which is formed by the cutout of the drill bit 3.
After curing of the jacket mixture 16 Preventer 14 and flat slide are removed and made the end seal 17 of the bore ( Fig. 6 ). After pulling the inner rod 2, the compression of the binder used as injection medium 18, gels or resin solutions in the individual stages (elastic sleeves 7 in the longitudinal direction of the injection tube) by means of a according Fig. 7 introduced into the injection tube 4 Packers 19, in particular a double packer. Due to the sealing positioning of the double packer 19 on both sides of the respective elastic sleeve 7 and its taking place under pressure feeding of the injection medium 18 into the injection tube 4 this passes through the openings 6 and the then contrasting elastic sleeve 7 in the bottom 15 or the joints, in which it is thus pressed or a targeted uplift injection can be carried out. Synthetic resins, cements, ultrafine cements, waterglasses or gels are used as injection media. After completion of the compression and the associated pressure drop, the sleeve 7 applies again to the injection tube 4 and seals the openings 6 from the outside. After the first compression, the injection tube 4 can then be cleaned and later re-pressed.

1

Außenbohrgestänge

1'

Aufsatzrohr

2

Innengestänge

3

Bohrkrone

4

Injektionsrohr

5

Aussparung

6

Durchbrechung

7

Manschette

8

Schutzblech

9

Bajonettverschluss

10

Rückschlagventil

11

Bohranlage

12

drückendes Wasser

13

Wand

14

Preventer

15

Boden

16

Mantelmischung

17

Endabdichtung

18

Injektionsmedium

19

Packer (Doppelpacker)

LIST OF REFERENCE NUMBERS

1

Außenbohrgestänge

1'

tower tube

2

inner rod

3

drill bit

4

injection tube

5

recess

6

perforation

7

cuff

8th

mudguard

9

bayonet catch

10

check valve

11

drilling rig

12

pressing water

13

wall

14

preventer

15

ground

16

jacket mixture

17

end seal

18

injection medium

19

Packer (double packer)

Claims (12)

1. A method for stabilizing soil sections, especially for compensation grouting, wherein injection media are introduced into spaced holes to perform elevation grouting, soil stabilization, fissure grouting, or pipe roof grouting, in which in a first step holes are drilled into the ground and then an injection medium is pressed into said holes through an injection pipe suitable for multiple injections,
   characterized in that
   an outer drilling rod assembly (1) made of steel, itself designed as an injection pipe (4) suitable for multiple injections and comprising a core drill bit (3) on its bottom side, is directly drilled into the soil (15), a stabilizing mix (16) is inserted either directly during drilling or after reaching the final drill depth via the inner rods (2) and the core drill bit (3), the inner rods (2) are pulled, and subsequently the injection medium (18) is injected under pressure in the individual stages, wherein said stages comprising elastic sleeves in the longitudinal extension of the injection pipe, using a packer (19) that is built into the injection pipe (4), wherein the injection pipe (4) either remains in the soil (15) as a lost drill and injection pipe (4) with core drill bit (3) or is removed after the injection.
2. The method for stabilizing soil sections according to claim 1,
   characterized in that
   drilling is performed using the displacement method.
3. The method for stabilizing soil sections according to claim 1,
   characterized in that
   the drilling fluid is supplied during drilling via the inner rods (2) in association with the core drill bit (3).
4. The method for stabilizing soil sections according to claim 1,
   characterized in that
   the stabilizing mix (16) is introduced directly during drilling or after reaching the final drill depth via the inner rods (2) and the core drill bit (3) into the annular clearance of the hole that is produced by the relief cut of the core drill bit (3).
5. The method for stabilizing soil sections according to claim 1,
   characterized in that
   the stabilizing mix (16) is introduced by applying pressure via the openings (6) that interact in association with the elastic sleeve (7) into the annular clearance of the hole that is produced by the relief cut of the core drill bit (3).
6. A device for stabilizing soil sections, consisting of individual outer drilling rod assemblies that can be screwed together, inner rods provided coaxially with the outer drilling rods, a core drill bit and an injection pipe suitable for multiple injections that is equipped with multiple openings along its longitudinal extension that extend radially inside the injection pipe onto which an elastic sleeve is provided to seal the openings,
   characterized in that
   the outer drilling rod assembly (1) is rigidly connected to the core drill bit (3) while said outer drilling rod assembly (1) itself is designed as steel injection pipe (4) suitable for multiple injections, wherein the elastic sleeves (7) are embedded in recesses (5) on the outer drilling rod assembly (1) and on the outside partly covered by guard plates (8).
7. The device for executing the method according to claim 6,
   characterized in that
   the diameter that the guard plates (8) form around the elastic sleeves (7) is congruent with the diameter of the outer drilling rod assembly (1).
8. The device for executing the method according to claim 6,
   characterized in that
   four openings (6) are arranged in opposing pairs in the recess (5) of the injection pipe (4).
9. The device for executing the method according to claim 6,
   characterized in that
   the recess (5) of the injection pipe (4) is covered by four guard plates (8) that are arranged in opposing pairs.
10. The device for executing the method according to claims 8 and 9,
    characterized in that
    the openings (6) are positioned such that they are located in that section underneath the elastic sleeve (7) that is not covered by the guard plates (8).
11. The device for executing the method according to claim 6,
    characterized in that
    the core drill bit (3) comprises a bayonet lock (9) or coupling for connecting it to the inner rods (2).
12. The device for executing the method according to claim 6,
    characterized in that
    at least the attachment pipe (1') following the first outer drilling rod assembly (1) is also designed as a valve-carrying injection pipe (4).

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