EP0903440B1 - Method and device for ground improvement with a powder binder - Google Patents

Abstract

The appliance feeds a binding agent into especially cohesive grounds with high water content. it has a charging container (22) for the agent, with a charging aperture (26), and a ventilation aperture open to the surroundings. A feeder tube (23) connected to the bottom of the container has a discharge opening (34) near its lower end which is closed by a controllable closure device. A vibrator device (24) is positioned within the feeder tube near its lower end and a filling level sensor (41) is also located near the lower end. The feeder tube is elastically suspended from the material container.

Description

The invention relates to a method and an apparatus for Introducing powdered binder into the soil, in particular in cohesive soil with a high water content, for the production of set consolidation columns in the ground to improve the Load capacity of the floor.

DE 43 04 816 A1 describes a device and a method for Stabilization of soft ground with dry mineral Powder known, in which a within a previously driven Protective tube driven into the underground Pipe is used, which has a cone seat valve at the front end having. This is with the powder to be introduced filled pipe driven into the ground with the valve closed and the valve after reaching the lowest position of the pipe opened by means of a rod; after that the powder is during a pulling of the pipe while filling the resulting bottom opening pressed out of the pipe by means of compressed air. The compressed air emerges from the valve and is supposed to flow along the outside Drain the pipe. This can lead to disturbances in the drainage of air, so that there are imperfections in the solidification column can arise.

DE 44 17 887 A1 describes a method and an apparatus for Known to increase the strength of soft ground, in which the Appears a screw arrangement within a pipe for conveying out of soil material and for the introduction of powdery binder features.

Flaws in the consolidation column are not to be expected because the powder by means of the screw while pulling the tube on everyone Case can be squeezed. However, the device is complicated and subject to wear with regard to the worm drive.

Proceeding from this, it is an object of the present invention to: To provide methods and apparatus that improve reliable implementation of the above-mentioned method to ensure.

The inventive method is characterized in that the pulling of the lock tube when falling below a lower one Minimum level of binder interrupted in the lock tube becomes.

In this way, there are imperfections in the solidification body to be produced safely avoided, as caused by uncontrolled, complete emptying of the lock tube or through Flaws in the fill level within the lock tube as a result of bridges could arise. After a stop the vibrator tube can be completely filled with the same powdery binders are made. Preferably there is a Always refill the lock tube when a Falling below an upper minimum fill level of binder is in the lock tube. Filling is done by blowing of powdery binder, the one used for conveying Compressed air through a vent in the feed tank can give way. Refilling stops when a maximum level is reached in the feed container is exceeded. This feed bin is usually constantly with a hose line a silo vehicle connected via a compressed air delivery device and from which the refill operations take place. The lock tube is shaken into the ground using known technology. Even when pulling the lock tube to deploy the Binder can be used to solidify the improved soil be shaken.

The powdery binder can be beneficial to the cohesive soil Wise withdraw water so that the load capacity of the cohesive soil significantly improved. It also takes place a material displacement by introducing the powdery binder in the ground instead, which is used for solidification and thus for leads to further improvement of the load capacity. Ground consolidation and displacement simultaneously causes squeezing of the soil water so that the binder with the soil water can set and forms a solidified column body.

The shaking of the lock tube and the introduction of the binder under the floor surface after shaking under Pulling the lock tube can create a consolidation column with a larger diameter than the lock tube can be repeated several times.

The process is repeated in a known manner at intervals, so that a grid of consolidation columns in the building ground, the Load capacity to be improved arises.

A device according to the invention comprises a feed container for powdery binder with one feed opening and one Vent opening, a lock tube, which is located at the bottom Feed container connects, with an outlet opening at the bottom End, and a jogger near the bottom of the Lock tube, which is within the cross section of the lock tube lies, and at least one level sensor near the lower end of the lock tube. In particular, the device comprises each have a further level sensor close to the upper one End of the lock pipe and in the feed container. The device is preferably on a leader who is on a caterpillar is mounted, attached. The powdery material is before Shake the lock tube filled into this. The weight of the material supports the shaking of the lock tube.

After complete shaking, open the closing device started pulling the lock tube, powdery binder is essentially pressureless from the Lock pipe flows out. The level sensors according to the invention ensure that the pulling is stopped and the Closing device in the event of an uncontrolled complete Emptying the lock tube or in the event of defects in the fill level, which can arise from bridging. As soon as the level sensor at the lower end of the lock tube the deflated condition, d. H. Falling below the fill level under the sensor, indicates the pulling of the device interrupted by no incorrect fillings in the emerging To create a column of material in the ground. Such a thing Shutting down triggers a refill of the lock tube from one silo vehicle connected to the feed container in motion, Bridging can be caused by the weight of the refilled, powdery binder or the slight excess pressure caused by generates the compressed air used to blow in the binder will be overcome. The refill process is done when reached of the level sensor in the feed container canceled and sets usually already when the height of the upper limit is undershot Level sensor in the lock tube again. The feed container serves to calm the flow in the to blow in powdery binder used in the lock tube compressed air as well as to blow off this compressed air, which as a result is not in the consolidation column can get. The vent of the Feed container is preferably provided with a dust filter. The lock tube is particularly elastic to the feed container attached. The feed opening of the feed container is with a hose connector for connecting a hose line provided from a silo vehicle.

In order not to get any floor material in when shaking the lock tube Allowing the same to occur is preferably the lock tube below the closing device with a plug made of gravel or the like to provide by the device first in a gravel fill is lowered on the ground surface. This is dispensable if the closing device is immediate is provided at the end of the lock tube.

The vibrator is advantageously located on lower end of the lock tube within its cross section; the free flow cross section of the lock tube for powdery Material is reduced in this area.

The lock tube can be attached elastically to the feed container be so that the feed container from the vibrations of the Lock tube is decoupled when shaking. An unwanted one Compression in the material feed container can thus be ruled out become.

The locking device at the lower end of the lock tube is preferably directly at a distance from the outlet opening above the vibrator.

The locking device of the lock tube can be in the form of a Slider, a flap or a pneumatic pinch valve device be trained. For the additional locking device at the lower end of the lock tube, this applies analogously same.

At the lower end of the feed container there can be another closing device be provided, the multiple refills of the lock tube from the feed container then allows if there is no permanent connection to the silo vehicle can stay.

The entire device is preferably via a guide carriage Can be moved on a leader that is directly on the feed container attacks.

Fig. 1

eine erfindungsgemäße Vorrichtung im Vertikalschnitt, befestigt an einem in dünnen Linien dargestellten Mäkler mit Tragraupe;

Fig. 2

die Verschließvorrichtung des Schleusenrohrs in einer ersten Ausführung;

Fig. 3

die Verschließvorrichtung des Schleusenrohrs in einer zweiten Ausführung;

Fig. 4

die Verschließvorrichtung des Schleusenrohrs in einer dritten Ausführung.

A preferred embodiment of the invention is explained below with reference to the drawings. Here shows

Fig. 1

an inventive device in vertical section, attached to a leader shown in thin lines with caterpillar;

Fig. 2

the locking device of the lock tube in a first embodiment;

Fig. 3

the locking device of the lock tube in a second embodiment;

Fig. 4

the locking device of the lock tube in a third embodiment.

A tracked vehicle is shown in FIG. 1 with thin lines 11 with a vertically erected leader device attached to it 12 recognizable. The caterpillar 11 is on the Floor surface 13 on. On the leader device 12 hangs in substantially vertically aligned a device 21 for insertion of powdery material under the floor surface for Manufacture of essentially vertical columns. On the device 21 are a feed container 22, a lock tube 23 and a vibrator device 24 recognizable as essential components. The feed container 22 is in two parts Carriage 25 performed on leader 12. At the bottom of the sled 25 the lock tube 23 is also suspended elastically. The Feed container 22 has a feed nozzle 26 which runs tangentially into the feed container 22 and at the one Hose connection from a silo vehicle is connectable. On the feed container 22 in the vent opening 42 is a sheet metal hood with a dust filter 27 put on. The feed container 22 ends in one at the bottom Funnel 28 which ends in a straight nozzle 29. This is via an elastic connector 30 with an expanded Inlet area 31 of the lock tube 23 connected. At the bottom At the end of the lock tube, its internal cross section is reduced by installing the vibrator 24. At the entrance to the A region with a reduced cross section is a sealing plug 32 in the closed position and shown in thin lines in the open Position shown. The lock tube 23 runs in one Cone section 33 with an outlet opening 34. In cross section is the round cross section of the feed container on the side 22 and the oval cross section of the lock tube 23 shown. There are a total of three level sensors on the device provided, namely a first level sensor 39 in the feed container 22, which is "completely filled" for the feed container can indicate a second level sensor 40 at the top of the lock tube 23, which is the condition "completely filled" for the lock tube 23 or "completely emptied "for the feed container 22 can display, and a third fill level sensor 41 at the lower end of the lock tube, which has the "completely emptied" state for the lock tube 23 should display.

In Figure 2 is a portion of the lock tube 23 with the shown the upper end of the vibrating device 24. Installation in Lock tube forms a transition funnel 35. The plug 32 with conical seat is here in the closed position solid lines and in open position in dashed lines Lines as seen in Figure 1. An actuation mechanism is not shown in detail. For this is a vertical operating rod with a corresponding outside or inside of the lock cylinder lying suitable.

FIG. 3 again shows a section of the lock tube 23 the upper part of the vibrating device 24 can be seen. Above the vibrating device has a swivel flap mechanism 36, that in solid lines in the open position and in dashed lines Lines are shown in the closed position. As an actuator can be done in the same way as previously described a vertical operating rod and one outside or inside of the lock cylinder lying serving serve.

FIG. 4 also shows a section of the lock tube 22 and the upper part of the vibrating device 24 can still be seen a sheet metal installation that forms a support surface 37. On the Support surface builds an elastic airbag 38 which with the Wall parts forms a pneumatically operated pinch valve. There is a compressed air line along the lock tube for actuation provided.

Closing devices of those shown in Figures 2 to 4 and the type described here can also in the transition cone 28th of the feed container 22 may be installed.

LIST OF REFERENCE NUMBERS

11

ramp vehicle

12

broker

13

ground surface

21

total device

22

feed container

23

sluice pipe

24

Jogger

25

guide carriage

26

loading port

27

Tin hood with dust filter

28

funnel

29

Support

30

elastic connector

31

extended entry area

32

plugs

33

cone section

34

outlet opening

35

Transition hopper

36

swiveling flap

37

support surface

38

air bag

39

Level sensor (in the feed container)

40

Level sensor (at the top of 23)

41

Level sensor (at the top of 23)

42

vent

Claims (12)

1. A method of introducing a powdery binding agent into the soil, especially into cohesive soil with a high water content, for the purpose of producing hardened consolidation columns in the soil for improving the load bearing capacity of the soil, wherein the binding agent is introduced underneath the soil surface (13) via a charging container (22) and a bottom feed pipe (23) vibrated into the soil while the bottom feed pipe (23) is being lifted,
   characterised in that the operation of lifting the bottom feed pipe (23) is interrupted once the level of the binding agent in the bottom feed pipe (23) falls below a lower minimum filling level.
2. A method according to claim 1,
   characterised in that the operation of re-filling the bottom feed pipe (23) commences once the level of the binding agent in the bottom feed pipe (23) begins to fall below an upper minimum filling level.
3. A method according to claim 2,
   characterised in that the operations of re-filling the bottom feed pipe (23) and filling-up the charging container (22) are interrupted once the level of the binding agent in the charging container (22) has reached a maximum filling level.
4. A device for introducing a powdery binding agent into the soil, especially into a cohesive soil with a high water content for the purpose of producing hardened consolidation columns in the soil for improving the load bearing capacity of the soil,
   comprising

   a charging container (22) for a powdery binding agent, having a charging aperture (26) and a ventilation aperture (42) opening into the environment,

   a bottom feed pipe (23)adjoining the lower end of the charging container (22) and having an exit aperture (34) near the lower end, which exit aperture (34) can be closed by a controllable closing device,

   characterised by
   a vibrating device (24) provided at the lower end of the bottom feed pipe (23) and positioned inside the cross-section of the bottom feed pipe (23), and
   at least one filling level sensor (41) near the lower end of the bottom feed pipe (23).
5. A device according to claim 4,
   characterised by a filling level sensor (40) near the upper end of the bottom feed pipe (23).
6. A device according to claim 4,
   characterised by a filling level sensor (39) in the charging container (22).
7. A device according to claim 4,
   characterised in that at the charging container (22) there is arranged a guiding slide (25) which is movable at a leader (12).
8. A device according to any one of claims 4 to 7,
   characterised in that the bottom feed pipe (23) is resiliently suspended at the charging container (22).
9. A device according to any one of claims 4 to 8,
   characterised in that the charging aperture (26) of the charging container (22) is provided with a hose sleeve.
10. A device according to any one of claims 4 to 8,
    characterised in that at the charging container (22), there is provided a dust filter (27) in the ventilation aperture (42).
11. A device according to any one of claims 4 to 10,
    characterised in that the closing device (32, 36, 38) provided at the lower end of the bottom feed pipe (23) is at a distance from the exit aperture (34) directly above the vibrating device (24).
12. A device according to any one of claims 4 to 11,
    characterised in that at the lower end of the charging container (22), there is provided a further closing device.

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