EP3034701B1 - Injection valve and method for generating an injection body into the ground - Google Patents

Description

The invention relates to an injection valve for an injection lance for generating an injection body in the bottom, with a valve body, in which at least one outlet opening is provided, which is closable and can be opened for leakage of an injection medium into the surrounding soil, according to the preamble of claim 1.

The invention further relates to a method for producing an injection body in the soil, in which an injection well is introduced into the soil, the injection well is filled with a curable shell mixture, an injection lance is arranged with an injection valve in the injection well and after curing of the shell mixture on the Injection valve, an injection medium is pressed into the ground, wherein the injection body is formed, according to the preamble of claim 8.

A generic injection valve and a generic method are known from US 4,309,129 A known. An injection medium exits from radially directed outlet openings, which are formed on the tubular injection lance.

Another injection valve and a method for generating an injection body in the soil go out of the DE 10 2008 056 261 B4 out. Injections in the soil or ground can fulfill different purposes. On the one hand, the compressive strength of the ground can be increased, which is advantageous, for example, for underpinning buildings. Another application is to increase the density of the soil by filling the pores in the soil with a gelling or hardening injection medium.

In particular, it is known to introduce a plurality of injection bodies in a grid-like manner into the ground and to arrange them so that the individual injection bodies overlap or at least touch each other. For example, a so-called sealing sole can be formed against penetrating groundwater. Such sealants are used in particular for sealing construction pits whose vertical walls are formed, for example, from bored piles, sheet piles or diaphragm walls. In order to form a sufficiently dense sole from the injection bodies, it must be ensured that the injection bodies reliably touch or overlap in order to avoid gaps or imperfections in the sealing sole. For this purpose, a reliable defined training of the injection body in the ground is of crucial importance. The greater possible deviations in the dimensions of the injection body, the closer the grid of the injection holes must be formed in order to obtain a desired security against defects. With a narrow grid, however, the number of necessary injection wells and thus the economic effort to create the sealing sole increases.

The DE 10 2008 056 261 B4 teaches to form the most uniform injection body, the provision of a centering on the valve body of the injection lance, so that it is arranged centrally in the injection well. In this case, the outflow of the injection medium into the surrounding soil takes place via outlet bores in a sleeve-shaped sleeve. In this case, the centering element is arranged from horizontally directed arms above the outlet holes, these arms also form a predetermined breaking point in the hardened jacket body for a uniform passage of the injection medium through the jacket body in the surrounding soil.

The GB 1 408 129 A discloses a rammer with a tube in which a striking element is arranged. In the cavity formed sand and concrete can be introduced via an external pipe.

The invention has for its object to provide an injection valve and a method for producing an injection body in the ground, with which injection body can be made in the ground with a very high accuracy.

The object is achieved on the one hand by an injection valve with the features of claim 1 and on the other hand by a method having the features of claim 8. Preferred embodiments of the invention are specified in the respective dependent claims.

The injection valve according to the invention is characterized in that the outlet opening is formed as an outlet slot, which is arranged horizontally and extends in the circumferential direction of the valve body. A first aspect of the invention It is therefore not to form the outlet opening by one or more cylindrical bores, but to provide an elongated outlet slot. This extends in a horizontal direction in the circumferential direction of the valve body. As a result, a reliable, large-scale, horizontal outflow of the injection medium from the injection valve is achieved in the surrounding area. Thus, a horizontal breaking of the cured shell body from the shell mixture in the injection body is effected with high reliability. By means of this horizontal predetermined breaking point thus formed, the injection medium can flow with a high degree of uniformity horizontally into the surrounding bottom region, so that a correspondingly defined spherical or circular disk-shaped injection body can be formed. Due to the uniform shape of the injection body, in particular a sealing sole with a high degree of tightness can be created with the smallest possible number of necessary injection bores.

It is particularly preferred according to the invention that the outlet slot is annular. The annular outlet slot thus extends without interruption around the circumference of the valve body.

According to a development of the invention, it is preferred that the valve body is tubular. The valve body may have a polygonal tubular shape, such as a quadrangular shape, or preferably a cylindrical outer contour. The tubular valve body has a central cavity through which the liquid injection medium from the injection lance can flow into the valve body and thus to the outlet slot.

According to the invention it is provided that an outlet channel is provided at a lower end of the valve body, which is closable via a closure element which is adjustable between a closed position and an open position in which the outlet slot is formed. The outlet slot does not have to be laboriously incorporated into a wall of a valve body. Rather, the outlet slot at the lower end of the valve body with an adjustable closure element
educated. The closure element is initially in a closed closure position, so that when a shunt of the injection lance with the injection valve no jacket mixture can get into the interior of the valve body. By introducing the injection medium into the valve body, the closure element is adjusted by a defined amount to the valve body, so that the annular discharge slot is formed in a simple manner.

A particularly accurate outflow of the injection medium from the injection valve is achieved according to the invention in that the closure element has a horizontally directed plate region, which protrudes in the horizontal direction over an outer periphery of the valve body. The plate area thus serves as a kind of lower guide element in order to deflect the injection medium emerging from the outlet channel in a horizontal direction.

A particularly preferred embodiment of the injection valve according to the invention is that the plate area is formed circular disk-shaped. As a result, a symmetrical formation of the injection body is supported.

In principle, the closure element may be made of any material, in particular of a metal. An economical production consists according to a development of the invention is that the closure element is formed of a plastic material. In addition, the valve body can be made of a plastic material, in particular by injection molding. In this case, the closure element is preferably designed so that its plate area bends elastically when introducing the injection medium into the valve body and so the elongated discharge slot is released.

A further advantageous embodiment of the invention consists in that the closure element has a guide neck, which is displaceably guided in the outlet channel. The closure element can be formed with a stop so that the closure element shifts only by a defined amount to release a defined exit slot. Preferably, the outlet channel is cylindrical in the valve body, wherein the guide neck is square, in particular triangular or square. In this case, the angular guide neck would only with its corner areas on the inside abut the outlet channel, so that between the inner wall of the outlet channel and the guide piece bypass channels are formed. Through this, the injection medium can flow past the guide neck to the outlet slot.

A further preferred embodiment of the invention consists in that a centering device for centering in an injection bore is provided on the valve main body. The centering device may in particular have a plurality of radially extending centering arms, which extend symmetrically away from the valve body. Preferably, these arms or elongated centering elements arcuately formed with a certain elasticity, in particular of a plastic material. In this way, the centering elements of the centering device can be adapted to different diameters of the injection bore and thus hold the injection valve centrally in the injection bore.

The invention further comprises an injection device for generating an injection body in the ground, with a tubular injection lance, at the lower end of which an injection valve is arranged, wherein the injection valve is designed according to the invention described above. The injection lance may be a metal or plastic tube, attached to the lower end of the injection valve, preferably screwed, is. The upper end of the injection lance is connected via a hose to a pump through which the injection medium is pumped through the injection lance to the injection valve.

According to a preferred embodiment of the invention, it is advantageous that a centering device is provided for centering the injection lance in an injection well. The centering device may in particular be formed with elongated, arcuate and / or elastically deformable centering elements, as they have been previously described. The centering device can be formed on the injection valve and / or on the elongated injection lance. In principle, it is also possible to arrange a plurality of centering devices, in particular two centering devices with an axial distance. In this case, a centering device may preferably be arranged on the injection valve and the other centering device in an upper region of the injection lance.

The method according to the invention is characterized in that an injection valve with a horizontal, circumferentially extending outlet slot is used and that the injection medium emerges annularly from the injection valve through the horizontal outlet slot.

In particular, in the method according to the invention the injection valve according to the invention described above is used. The advantages described above can be achieved. Above all, the method can produce injection bodies in the soil with a high degree of uniformity and symmetry. This allows an efficient production, for example, a sealing sole with a relatively low cost while maintaining good security against defects.

According to a development of the method according to the invention, it is provided that an approximately spherical injection body is formed around the injection valve. When the injection medium exits the injection valve, the hardened jacket mixture in the injection bore is broken around the injection valve, whereby the injection medium spreads through the annular gap and spreads in all surrounding directions in the surrounding bottom region. Here, the approximately spherical injection body is formed.

According to a development of the process according to the invention, soft gels, hard gels, cement suspensions or superfine cement suspensions with and without additives are used as the injection medium. In particular, bentonite-containing suspensions or suspensions based on water glass can be used.

Fig. 1

eine Seitenansicht eines erfindungsgemäßen Injektionsventiles in der Verschlussposition;

Fig. 2

eine Seitenansicht des Injektionsventiles von Fig. 1 in Öffnungsposition;

Fig. 3

eine perspektivische Ansicht eines Ventilgrundkörpers des Injektionsventiles von Figuren 1 und 2;

Fig. 4

eine Draufsicht auf den Ventilgrundkörper von Fig. 3;

Fig. 5

eine Draufsicht auf ein Verschlusselement für ein erfindungsgemäßes Injektionsventil;

Fig. 6

eine Seitenansicht des Verschlusselementes von Fig. 5; und

Fig. 7

eine schematische Querschnittsansicht zu einer erfindungsgemäßen Injektionsvorrichtung im Boden.

The invention will be further elucidated on the basis of preferred exemplary embodiments, which are illustrated schematically in the drawings. In the drawings show:

Fig. 1

a side view of an injection valve according to the invention in the closed position;

Fig. 2

a side view of the injection valve of Fig. 1 in open position;

Fig. 3

a perspective view of a valve body of the injection valve of FIGS. 1 and 2 ;

Fig. 4

a plan view of the valve body of Fig. 3 ;

Fig. 5

a plan view of a closure element for an injection valve according to the invention;

Fig. 6

a side view of the closure element of Fig. 5 ; and

Fig. 7

a schematic cross-sectional view of an injection device according to the invention in the ground.

An embodiment of an injection valve 20 according to the invention will be described below in connection with FIGS FIGS. 1 to 4 explained. The injection valve 20 has an approximately cylindrical and tubular valve body 22. An approximately cylindrical outlet channel 23 extends from an upper connection opening 26 to a lower outlet opening 24 through the valve main body 22. In the region of the upper connection opening 26, a connecting device 28 is formed for connecting an injection lance 12. The connecting device 28 is formed in the illustrated embodiment as an internal thread into which an external thread on the injection lance 12 can be screwed.

According to the state of Fig. 1 the lower outlet opening 24 of the outlet channel 23 is closed by a closure element 40. The closure element 40 has a circular disk or annular plate region 42 whose outer diameter is larger than the outer diameter of the cylindrical valve body 22 is formed.

As in particular from the Fig. 2 can be removed, is provided at the top of the plate portion 42 centrally a square guide stub 44. The closure element 40 with the plate region 42 and the guide neck 44 is preferably formed integrally from a plastic material. The angular guide piece 44 has corner regions 46, which lie displaceably against an inner wall of the outlet channel 23. Due to the angular formation of the guide stub 44 so remain between the side wall surfaces of the guide stub 44 and the cylindrical inner wall of the outlet channel 23 four channels through which an injection medium to the outlet port 24 can flow.

In Fig. 2 the injection valve 20 is shown in an open position, wherein the closure element 40 is pushed out by a defined amount from the valve body 22 and the outlet channel 23. As a result, an annular, horizontally directed outlet slot 30 is formed annularly around the guide neck 44 at the outlet opening 24. Through this annular horizontal exit slot 30, the injection medium can flow out uniformly in all radial directions from the outlet opening 24 and the outlet slot 30. The radially outwardly projecting disk-shaped plate region 42 in this case represents a reliable deflection of the injection medium flowing out of the outlet channel 23 at a certain pressure.

In the axially inserted closure position of the closure element 40 according to Fig. 1 contact the plate portion 42, the lower end of the valve body 22 and the guide piece 44 a stop bar 32 which extends transversely through the outlet channel 23, in particular the Fig. 4 can be seen. In the transversely directed horizontal stop bar 32, a central retaining bore 34 is formed, with which the guide sleeve 44 of the closure element 40 can be secured approximately by means of a screw. In such an embodiment, an introduction of injection medium into the outlet channel 23 of the valve body 22 would not lead to an axial displacement of the entire closure element 40, but in a formation of a corresponding elastic plastic to a deflection of the plate portion 42 down. As a result of this deflection of the plate region 42, an annular outlet slot 30 would then also be formed at the lower end of the valve body 22.

At the upper end of the valve body 22, an approximately conically shaped centering device 36 is formed with a total of five arcuate upwardly extending centering 38. Due to the arcuate, slightly S-like shape of the centering 38, these can relatively easily adapt from a maximum diameter to smaller diameter of injection wells and thus ensure efficient centering of the injection valve 20 in an injection well.

In the FIGS. 5 and 6 the closure element 40 is shown in more detail with the circular disk-shaped plate region 42, on whose upper side a block-like guide neck 44 with four corner regions 46 is formed.

In connection with the schematic representation of Fig. 7 the construction of an injection device 10 according to the invention and the implementation of a method according to the invention for producing an injection body 8 in the bottom 2 are explained in more detail. In the bottom 2, an injection bore 3 is first introduced with a conventional drilling process. The injection bore 3 is created to a desired depth, in which an injection body 8 is to be formed. Subsequently, the injection hole 3 is filled with a curable shell mixture 4, which may be in particular a cement mixture and cures to a solid shell body 5. However, the sheath body 5 has only a limited strength, so that this, as will be described below, 7 can be broken open by introducing an injection medium.

Before or after filling the shell mixture 4 in the injection hole 3, in any case before curing of the shell mixture 4 to the solid shell body 5, a tubular injection lance 12 is centrally arranged in the injection hole 3. At the lower end of the injection lance 12 of the injection device 10, an injection valve 20 is attached. By introducing a liquid injection medium 7 at the upper end of the injection lance 12 via a pumping device, not shown, a closure element 40 of the injection valve 20 at the lower end of the injection lance 12 is pushed axially downwards. As a result, an annular horizontal outlet slot 30 is formed at the lower end of the injection valve 20. From this annular exit slot 30, the liquid injection medium 7 can escape into the surrounding area in all horizontal directions.

Due to the axial displacement of the closure element 40 with the circular disk-shaped plate region 42 and the simultaneous emergence of the injection medium 7 from the outlet slot 30 in the only slightly solidified shell body 5 a substantially circumferential in the horizontal direction crack is formed. Through this annular crack or slot, the injection medium 7 can continue to emerge radially outward into the surrounding region of the bottom 3 and there with a very good dimensional accuracy form an approximately spherical injection body 8 in the bottom 2. The injection lance 12 usually remains in the bottom 2.

By appropriate arrangement of further injection bores 3, which are arranged in a grid-shaped manner with a spacing of approximately the diameter of an injection body 8 or smaller, a sealing sole in the bottom 2 can be created by a multiplicity of injection bodies 8 formed.

Claims (10)

1. Injection valve for an injection lance (12) for producing an injection body (8) in the ground (2), with a valve base body (22), in which at least one discharge opening (24) is provided which is closable and can be opened for discharging an injection medium (7) into the surrounding ground (2),
   characterized in that
   the discharge opening (24) is designed as a ring-shaped discharge slit (30) which is arranged horizontally and extends in the circumferential direction of the valve base body (22),
   in that on a lower end of the valve base body (22) an outlet duct (23) is provided which is closable by a closing element (40) that is adjustable between a closed position and an open position, in which the ring-shaped discharge slit (30) is formed, and
   in that the closing element (40) has a horizontally directed plate region (42) which projects in the horizontal direction beyond an external circumference of the valve base body (22).
2. Injection valve according to claim 1,
   characterized in that
   the valve base body (22) is designed in a pipe-shaped manner.
3. Injection valve according to claim 1 or 2,
   characterized in that
   the plate region (42) is designed in the shape of a circular disk.
4. Injection valve according to any one of claims 1 to 3,
   characterized in that
   the closing element (40) is formed of a plastic material.
5. Injection valve according to any one of claims 1 to 4,
   characterized in that
   the closing element (40) has a guide stub (44) which is guided in a displaceable manner in the outlet duct (23).
6. Injection device for producing an injection body (8) in the ground (2), with a pipe-shaped injection lance (12), at the lower end of which an injection valve (20) is arranged,
   characterized in that
   the injection valve (20) is designed according to any one of claims 1 to 5.
7. Injection device according to claim 6,
   characterized in that
   a centering means (36) for centering the injection lance (12) in an injection bore (3) is provided.
8. Method for producing an injection body (8) in the ground (2), in which

   - an injection bore (3) is introduced into the ground (2),

   - the injection bore (3) is filled with a hardenable jacket mixture (4),

   - an injection lance (12) with an injection valve (20) is arranged in the injection bore (3) and

   - after hardening of the jacket mixture (4) an injection medium (7) is injected via the injection valve (20) into the ground (2), whereby the injection body (8) is formed,

   characterized in that

   - an injection valve (20) according to any one of claims 1 to 5 with a horizontal ring-shaped discharge slit (30) extending in the circumferential direction is used and

   - in that through the horizontal discharge slit (30) the injection medium (7) is discharged in a ring-shaped manner from the injection valve (20).
9. Method according to claim 8,
   characterized in that
   an approximately spherical injection body (8) is formed.
10. Method according to claim 8 or 9,
    characterized in that
    as injection medium (7) soft gels, hard gels, cement suspensions or ultra-fine cement suspensions with or without additives are used.

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