Method for producing an injection anchor in the ground and automatic post-grouting machine for the same

Abstract

The invention relates to a method and a device for producing an injection anchor in the ground, wherein a bore is created in the ground, a hardening material for forming the anchor foot is injected by means of an injection member at least in a partial region of the bore, and after partial, not yet complete, hardening of the material a post-grouting medium is introduced under pressure in a region of the anchor foot via a post-grouting member, by which medium the not yet completely hardened anchor foot is broken up. According to the invention, provision is made for an automatic post-grouting machine to be connected to the post-grouting member, by which machine the post-grouting medium for breaking up the not yet hardened anchor foot is automatically introduced into the post-grouting member at a freely specifiable time.

Claims

1. A method for producing an injection anchor in the ground, wherein a bore is created in the ground, a hardening material for forming a primary anchor foot is injected by means of an injection member at least in a partial region of the bore, and after partial, not yet complete, hardening of the material a post-grouting medium is introduced under pressure into a region of the primary anchor foot via a post-grouting member, by which medium the not yet completely hardened primary anchor foot is broken up and forms a secondary anchor foot having a size larger than the primary anchor foot, wherein an automatic post-grouting machine is connected to the post-grouting member, by which machine the post-grouting medium for breaking up the not yet hardened primary anchor foot is automatically introduced into the post-grouting member at a freely specifiable time, and the automatic post-grouting machine is provided with a control unit with a timeswitch, in which the freely specifiable time for carrying out the automatic post-grouting is input such that the automatic introduction of the post-grouting medium is carried out at the freely specified time without intervention by personnel.

2. The method according to claim 1, wherein the post-grouting medium is a liquid or a gas by which the primary anchor foot is broken up, and a hardenable medium is introduced temporally spaced into the broken-up anchor foot.

3. The method according to claim 1, wherein a hardenable medium is used as the post-grouting medium for forming the secondary anchor foot.

4. The method according to claim 1, wherein the injection member for injecting the hardenable material and the post-grouting member for injecting the post-grouting medium remain in the bore.

5. The method according to claim 1, wherein the injection member is a drilling tool with which the bore in the ground is created.

6. The method according to claim 1, wherein the post-grouting member has at least one exit opening, through which the post-grouting medium is introduced into the bore.

7. The method according to claim 1, wherein a pressure for introducing the post-grouting medium of at least 10 bar is set.

8. An automatic post-grouting machine for a method according to claim 1, wherein a pressure means is connected by at least one line to the post-grouting member and introduces the post-grouting medium under pressure into the post-grouting member.

9. The automatic post-grouting machine according to claim 8, wherein at least one container for receiving the post-grouting medium is provided.

10. The automatic post-grouting machine according to claim 8, wherein the pressure means comprises a pump or a compressor.

11. The automatic post-grouting machine according to claim 8, wherein the automatic post-grouting machine is connected to at least one post-grouting member by way of the at least one line.

12. The automatic post-grouting machine according to claim 7, wherein the pressure for introducing the post-grouting medium is set between 15 bar and 40 bar.

13. The method according to claim 2, wherein the liquid is water and the gas is compressed air.

Description

(1) In the sole FIGURE, the performance of a preferred variant embodiment of the method according to the invention is illustrated in five steps.

(2) Here, in a step a) a bore 5 is formed in a ground or an approximately vertical wall region by means of a drilling tool 20. By way of a drill tip 21, a hardenable material 12 can be introduced into the bore 5 in order to form a primary anchor foot 16, as illustrated clearly in the steps b) and c).

(3) The rod-shaped tension member 14 for forming the injection anchor 10 and also the rod-shaped injection member 22 may be arranged within the drilling tool 20, so that they can be introduced into the bore 5 already with the drilling tool 20. After reaching the desired depth, the outer drilling tool 20 can be withdrawn from the bore 5 again, with the cavity in the bore 5 being filled at least in regions with the hardenable material 12, as clearly illustrated in the steps c) and d). With this method, the drilling tool 20 serves simultaneously as an injection member 22 for injecting the hardenable material 12 for forming the primary anchor foot 16 and also optionally for forming a further region of the injection anchor 10.

(4) According to the invention, a hose-shaped post-grouting member 30 with a hollow basic body 32 is introduced into the bore 5 with the tension member 14, as long as the hardenable material 12 is still in a soft, free-flowing state. At the soil-end end region of the basic body 32 of the post-grouting member 30 there is arranged, at least in portions, a post-grouting portion 34 which covers grouting openings 36 in the tubular basic body 32.

(5) As clearly illustrated in step e), an automatic post-grouting machine 40 according to the invention is connected to the free end of the post-grouting member 30 which protrudes out of the ground by way of a connector 38 and a line 49.

(6) The automatic post-grouting machine 40 has a box-like frame 42 with a control unit 44, at least one container 48 for receiving a post-grouting medium 26, and a pressure means 50 for generating a desired injection pressure. The control unit 44 is provided with a timeswitch 46, with which a time can be input at which, by means of the automatic post-grouting machine 40, post-grouting medium 26 from the container 48 can be automatically introduced into the post-grouting member 30 under pressure by means of the pressure means 50.

(7) Due to the introduction of the post-grouting medium 26, which may in particular be identical to the hardenable material 12, at a specifiable time at which the primary anchor foot 16 is partially, but not yet completely, hardened, can be introduced into the bore 5. In this case, at a pressure of for example 15 bar, the one, or the plurality of, post-grouting portion(s) 34 on the post-grouting member 30 can be fractured, so that the exit openings 36 in the basic body 32 of the post-grouting member 30 are uncovered. The flowable post-grouting medium 26 can in this case penetrate into the region of the primary anchor foot 16, break it up and expand it to form an enlarged, approximately pear-shaped, secondary anchor foot 18. Once hardening is complete, a secondary anchor foot 18 of widened diameter is thus obtained, into which the tension member 14 is securely bonded, so that relatively high forces can be transferred into the ground by way of the tension member 14 and the widened secondary anchor foot 18.

(8) In an upper region of the injection anchor 10, the tension member 14 may be surrounded by a cylindrical tube member 15.

(9) After termination of the post-grouting, which can be carried out in particular without personnel at weekends, the automatic post-grouting machine 40 can be removed again by detaching the line 49 at the connector 38 and be provided for a further post-grouting operation.