EP1630298B1 - Method of making a slotted wall by means of a trench cutter - Google Patents

Abstract

The method involves lowering a trench wall cutter (10) with a rotatably driven cutting wheel into soil (3), wherein soil material located below the cutting wheel is stripped and a cut trench (1) is formed, and supplying a settable liquid into the cut trench. A gas e.g. air is supplied into the cut trench in a defined manner. An independent claim is also included for a trench wall cutting device.

Description

The invention relates to a method for producing a trench wall in the ground according to the preamble of claim 1, wherein a trench cutter is lowered with at least one rotationally driven cutting wheel in the ground, below the cutting wheel befindliches soil material processed and a Frässchlitz is made, and a abbindbare Liquid is introduced into the milling slot.

The invention further relates to a Schlitzwandfräsvorrichtung for producing a slot wall according to the preamble of claim 7, including a frame, at least one rotatably mounted on the frame cutting wheel and a drive with which the cutting wheel is set in a rotary motion, thereby below the cutting wheel befindliches soil material can be cleared away to form a Frässchlitzes.

A method for producing a slot wall in the bottom is from DE 195 30 827 C2 known. In this so-called two-phase process, a milling slot is excavated in a first phase and the excavated soil excavation of the milling slot is conveyed to above ground. The resulting milling slot is filled with a support suspension and thereby supported. In a second phase after the sinking of the milling slot, a hardening suspension is introduced into the slot while displacing the support suspension.

At one of the DE 41 41 629 C2 known one-phase process, the slot is supported from the beginning by a hardening suspension, which is prepared by mixing excavated soil material with a settable liquid over-days.

To carry out these known methods can from the DE 34 24 999 C2 or CH 490 579 A known trench wall milling application find. These known trench wall cutters have a trimming frame and, attached to this underside, rotating drivable cutting wheels. Ground material cleared from the cutting wheels is supplied by the cutting wheels to a suction device attached to the milling frame and transported to the surface.

From the German patent application with the file number 103 08 538 is another, generic method for producing a slot wall known. In this known method, the hardening suspension is not made outside the slot, but directly in the slot itself. For this purpose, ground material removed by the cutting wheels is, as it were, mixed with the settable liquid "in situ" by the action of the cutting wheels in the milling slot, thereby producing a hardening liquid-soil mixture. In this method, the mixed with the curable liquid, cleared soil material is at least partially left in the milling slot, where it can harden to form the slot wall. This eliminates the need to elaborate the entire cleared soil material by pumping equipment consuming to overground.

For supplying the settable liquid in the Frässchlitz is from the German patent application with the file number 103 08 538 a feeder known, which is arranged on the frame of the trench wall cutter.

Object of the present invention is a method and a Schlitzwandfräsvorrichtung for producing a Specify diaphragm wall in the floor, with which particularly high-quality diaphragm walls can be created particularly easily.

The object is achieved by a method having the features of claim 1 and a Schlitzwandfräsvorrichtung with the features of claim 7. Preferred embodiments are specified in the respective subclaims.

Among other things, it is provided in the method according to the invention that a gas, in particular air, is introduced into the milling slot in a defined manner.

A basic idea of the invention can be seen in that, in addition to the settable liquid, a gas is added during milling into the milling slot. This gas exits in the milling slot and rises in the existing in Frässchlitz suspension upwards. This movement of the gas ensures a particularly good mixing of the hardening suspension in the milling slot and thus allows the production of particularly high-quality diaphragm walls. In particular, can be counteracted by the gas addition according to the invention settling of larger and / or heavier suspended particles and thus a particularly good homogeneity in the suspension can be obtained, resulting in particularly homogeneous and high-quality slot walls. In addition, can be counteracted by the addition of gas premature, in particular localized curing of the settable suspension.

The curable or settable suspension according to the invention is understood to mean a suspension which is produced by mixing the settable liquid with cleared soil material. The settable suspension is suitably made directly in the cutting slot itself, ie the mixing of the settable liquid with the soil material takes place in the milling slot, in particular in the area of the cutting wheel and by Fräsradwirkung.

In contrast to a drilling method in which the axis of rotation of a soil working tool coincides with its advancing direction, the method according to the invention is a milling method in which at least one soil working tool designed as a cutting wheel is rotated about an axis of rotation which is angular, i.e. angular. is not arranged parallel to the advancing direction. The at least one cutting wheel is rotatably driven according to the invention, for which purpose a drive is provided. Advantageously, two axially parallel driven cutting wheels or two axially parallel driven Fräsradpaare are provided on the bottom side of the trench wall cutter.

The gas introduced into the milling slot can basically be chosen as desired in terms of its composition. Particularly economical, however, is the use of air that can be pumped, for example, from the vicinity of the Frässchlitzes. The gas is suitably added with overpressure into the milling slot.

In principle, it is possible to introduce the gas and / or the settable liquid at any point in the milling slot. For a particularly effective mixing, however, the gas and / or the liquid is advantageously introduced in the region of the Frässchlitzgrundes. For the purpose of introducing the gas and / or the settable liquid may in principle be provided introduction means which are separated and / or spaced from the trench wall cutter. For example, in addition to the trench wall cutter, a common inlet pipe or separate pipes for the gas and the settable liquid can be introduced into the trimming slot. Provided according to the invention, however, that the gas and the settable liquid are introduced to a frame of the trench wall cutter in the region of the cutting wheel in the Frässchlitz. By introducing the gas and the settable liquid in this area, the mixing effect of the rotating cutting wheels can be exploited in a particularly efficient manner and thus the homogeneity and the quality of the trench wall to be created be further improved. According to this embodiment, the gas and / or the settable liquid introduction means are advantageously arranged on the trench wall cutter, in particular on its frame. Preferably, the gas and / or the settable liquid are introduced centrally between two paraxial cutting wheels or Fräsradpaaren. The gas and / or the settable liquid can be introduced into the milling slot at one or more points of introduction.

In principle, it is possible to align the flow of the introduced gas and / or the introduced, settable liquid arbitrarily in the milling slot. In this context, the flow of the introduced materials is understood to mean that flow which takes place immediately upon introduction, i. formed at the exit from the respective initiating devices, and may also exist when stationary cutting wheels and immovable trench wall cutter. In particular, this is not understood to mean the movement of the gas or the liquid, which arises due to the agitation of the cutting wheel or due to buoyancy forces.

However, it is particularly preferred according to the invention that the flow of the introduced gas and / or the introduced, settable liquid is directed to the cutting wheel. As a result, it is possible to flush the cutting wheel free particularly effective of abraded soil material, whereby a particularly good milling progress can be achieved. Conveniently, the flow of the introduced gas and / or the introduced settable liquid is directed at least approximately in the advancing direction of the trench wall cutter. In particular, the flow may affect at least one cutting wheel, preferably two cutting wheels or two pairs of cutting wheels, that is to say touch tangentially. For this purpose, outlet openings of the introduction devices are preferably arranged centrally between the suitably axially parallel cutting wheels.

A particularly preferred development of the invention is characterized in that the gas is introduced into the milling slot with a flow profile which, in particular, concentrically surrounds a flow profile of the settable liquid when it is introduced, or which is surrounded concentrically by this flow profile in particular. In this case, the cross section through the flow during the introduction of the gas and / or the settable liquid perpendicular to the flow direction can be understood as the flow profile. According to this embodiment, it is thus provided that the flows of the gas and the settable liquid at least partially surround. For this purpose, the introduction means may comprise, for example, an annular nozzle. It is particularly preferred that the gas is guided in particular concentrically around the outside of the liquid. In this case, the beam power of the liquid jet can be improved and in particular a larger beam range can be achieved.

In principle, the gas can be introduced into the milling slot in any operating state of the trench wall cutter. It is particularly preferred that the gas during lowering and / or pulling the trench wall cutter, in particular during operation of the at least one cutting wheel, is supplied. It can also be provided to temporarily shut down the trench wall cutter in the direction of propulsion during the introduction of gas, i. to perform neither a lowering nor a pulling movement. In principle, the gas can preferably be fed further even after complete removal of the trench wall cutter from the trimming slot.

According to a further embodiment of the present invention it is provided that the gas is supplied with a gas pressure in the Frässchlitz, which is varied depending on the current cutting depth of the trench wall cutter. This embodiment is particularly advantageous when the gas is introduced into the cutting slot on the frame of the trench wall cutter, ie at a milling depth-dependent introduction point. The present embodiment allows the changes of the hydrostatic pressure in the milling slot with variable depth of cut to take into account and initiate the gas, for example, with an at least approximately constant overpressure relative to the ambient pressure of the trench wall cutter. However, the gas pressure can also be changed disproportionately or disproportionately with the hydrostatic pressure, for example.

It is also particularly advantageous that the settable liquid is mixed in the milling slot, in particular by Fräsradwirkung, with abgearbeitetem soil material to form a curable suspension. According to this embodiment, the suspension is thus produced "in situ" in the milling slot and in particular not above ground. The cutting wheel serves both for removing soil material and for subsequent mixing of this soil material with the settable liquid.

In the trench wall milling device according to the invention, it is provided that a gas conveying device is provided for the defined introduction of a gas into the trimming slot. The trench wall cutting device according to the invention is particularly suitable for carrying out the method according to the invention, whereby the advantages listed in this context can be achieved. Under the defined introduction in the context of the invention can be understood in particular that the gas is specifically promoted by means provided for this purpose in the Frässchlitz and not, for example, only entrained by the trench cutter during drilling and released later. The gas delivery device can also be referred to as an introduction device for the gas.

In order to obtain a particularly good mixing of the suspension, the invention provides that the gas delivery device has at least one Gaseinleitdüse which is arranged on the frame in the region of the cutting wheel. Preferably, the Gaseinleitdüse is arranged centrally between two adjacent, in particular paraxial cutting wheels or Fräsradpaaren.

It is further provided that a liquid delivery device is provided for introducing a settable liquid into the milling slot, wherein the liquid delivery device has at least one Flüssigkeitseinleitdüse which is arranged on the frame in the region of the cutting wheel. The liquid delivery device can also be referred to as the introduction device for the settable liquid. Suitably, the Flüssigkeitseinleitdüse is arranged centrally between two, preferably axially parallel cutting wheels or Fräsradpaaren.

A particularly high jet range for the gas and / or liquid jet can be provided according to the invention in that the gas inlet nozzle surrounds the liquid inlet nozzle, preferably ring-like and / or concentric, or is surrounded by this liquid inlet nozzle, preferably ring-like and / or concentric. For this purpose, the gas inlet nozzle and / or the liquid inlet nozzle are suitably designed as an annular nozzle or as a ring segment nozzle.

According to the invention it can be provided that the gas and / or the settable liquid is introduced into the milling slot at one or more separate locations. If an initiation is provided at several points in the milling slot, a plurality of introduction devices, in particular a plurality of inlet nozzles, can be provided for this purpose.

To generate a gas flow for the defined introduction of the gas into the milling slot, provision can be made, in particular, for the gas conveying device to have a gas pressure generating device arranged outside the milling slot. The gas pressure generating device may, for example, a pump, in particular a piston pump, and / or also have a pressure vessel. Advantageously, the gas conveying device serves to convey ambient air into the milling slot.

A particularly good cleaning of the at least one cutting wheel of soil material and thus a particularly good milling progress can be obtained by directing the gas inlet nozzle and / or the liquid introduction nozzle onto the at least one cutting wheel. Suitably, the gas flow from the gas inlet nozzle and / or the liquid flow from the liquid inlet nozzle touches the cutting wheel. In particular, these flows may also affect two adjacent cutting wheels simultaneously, i. flow tangentially.

The gas inlet nozzle and / or the Flüssigkeitseinleitdüse may for example have a circular or a slot-like opening cross-section.

Fig. 1

eine teilweise geschnittene Frontansicht einer erfindungsgemäßen Schlitzwandfräsvorrichtung;

Fig. 2

eine teilweise geschnittene, perspektivische Detailansicht einer Gaseinleitdüse und einer Flüssigkeitseinleitdüse, die im Rahmen einer weiteren erfindungsgemäßen Schlitzwandfräsvorrichtung angeordnet sind;

Fig. 3

eine Seitenansicht eines Rahmens einer weiteren erfindungsgemäßen Schlitzwandfräsvorrichtung; und

Fig. 4

eine Teilansicht des Schnittes A-A des Rahmens aus Fig. 3.

The invention will be explained in more detail with reference to preferred embodiments, which are illustrated in the figures. In the figures show schematically:

Fig. 1

a partially sectioned front view of a Schlitzwandfräsvorrichtung invention;

Fig. 2

a partially sectioned, perspective detail view of a Gaseinleitdüse and a Flüssigkeitseinleitdüse, which are arranged in the context of another Schlitzwandfräsvorrichtung invention;

Fig. 3

a side view of a frame of another Schlitzwandfräsvorrichtung invention; and

Fig. 4

a partial view of the section AA of the frame of FIG. 3rd

Equivalent elements are indicated in all figures throughout with the same reference numerals.

A slot wall milling device according to the invention is shown in FIG. It has a trench wall cutter 10 with a frame 20, on the bottom side two cutting wheels 12, 12 'are rotatably mounted. The cutting wheels 12, 12 'are formed as Fräsradpaare with two Einzelfräsrädern, which are arranged perpendicular to the plane behind the other and coaxial. On the circumference of the cutting wheels 12, 12 'are cutting teeth 13 and perpendicular to the plane pivotable folding teeth 14 are provided.

For rotationally driving the two axially parallel arranged cutting wheels 12, 12 'are on the frame 20 designed as hydraulic rotary two drives 15, 15' are provided, which are supplied via supply lines 40 with hydraulic fluid.

By lowering the trench wall cutter 10 in the advancing direction 80 in the bottom 3 and simultaneous operation of the cutting wheels 12, 12 'is formed in the bottom 3, a milling slot 1 with approximately rectangular milling cross-section.

The trench wall milling device furthermore has a liquid introduction device for introducing settable liquid into the milling slot 1. This liquid introduction device has a liquid line 68 which, starting from a liquid pump, not shown in the figure, extends inside a guide rod 33 of the frame 20 in the advancing direction 80 to the frame 20 and ends there in a liquid introduction nozzle 60. The Flüssigkeitseinleitdüse 60 is disposed between the two cutting wheels 12, 12 ', that the emerging from it in the direction of advance 80 liquid jet, the teeth 13, 14 of both juxtaposed cutting wheels 12, 12' tangentially touched and thus flushed abgegearbeitetem soil material.

In addition, the trench wall milling device has a gas delivery device, which can also be referred to as a gas introduction device. This gas conveying device has a gas line 58, which, starting from a not shown in FIG. 1 and arranged outside the Frässchlitzes 1 Gas pressure generating device in the interior of the guide rod 33 extends to the frame 20 and ends there in a gas inlet nozzle 50. The gas inlet nozzle 50 is designed as a circular ring nozzle which surrounds the liquid inlet nozzle 60 provided with a circular inlet cross section in an annular manner. Because of this arrangement, the gas inlet nozzle 50 is located centrally between the two cutting wheels 12, 12 'and the gas jet exiting the gas inlet nozzle 50 directed tangentially to the cutting teeth 13, 14 of both cutting wheels 12, 12'. The gas jet surrounds the liquid jet like a ring.

The frame 20 is designed so that its cross-section is significantly smaller than the milling cross section of the two cutting wheels 12, 12 ', so that in the field of cutting wheels 12, 12' and above a largely unimpeded by the geometry of the frame 20 thorough mixing of the through the cutting wheels 12, 12 'at the bottom of the milling slot 1 processed soil material can be done with the introduced through the Flüssigkeitseinleitdüse 60, settable liquid.

A detailed view of a further slot wall milling device according to the invention is shown in FIG. 2 shows a frame 20 of a trench wall cutter 10 according to the invention, on which a gas inlet nozzle 50 and a liquid inlet nozzle 60 are arranged. For the sake of clarity, no cutting wheels or their drives are shown in FIG.

To supply the Flüssigkeitseinleitdüse 60, a liquid line 68 is provided in the frame 20. The liquid introduction nozzle 60 is formed through an end opening in a substantially cylindrical liquid nozzle member 65. In its inflow region, following the liquid line 68, the liquid nozzle element 65 has a frustoconical portion 62, in which the flow cross-section for the liquid tapers. Adjoining the truncated cone-like section 62 in the flow direction is a cylindrical section 64, at the end of which the liquid introduction nozzle 60 is formed. The cylindrical portion 64 and the frusto-conical portion 62 of the liquid nozzle member 65 are arranged coaxially with each other with a center axis which is parallel to the advancing direction 80 of the trench wall cutter 10.

To supply the gas inlet nozzle 50 with gas, a gas line 58 is provided in the frame 20. While the gas line 58 in the region of the nozzles 60, 50 runs parallel to the advancing direction 80, the liquid line 68 is arranged at an angle thereto.

The Gaseinleitdüse 50 is formed as an annular ring nozzle which surrounds the formed with a circular cross-section fluid nozzle 60. The gas introduction nozzle 50 is formed between the outer wall of the cylindrical portion 64 of the liquid nozzle member 65 and the cylindrical inner wall of a through hole 52 of a ring-like hole member 51 which surrounds the cylindrical portion 64 of the liquid nozzle member 65 in its lower portion. The hole element 51, which can also be referred to as a replaceable nozzle holder, is detachably arranged on the underside of the frame 20.

For supplying gas to Gaseinleitdüse 50, an annular chamber 53 is formed in the frame 20, which surrounds the cylindrical portion 64 and the frusto-conical portion 62 of the liquid nozzle member 65 above the hole member 51 ring-like, and which with the gas line 58 via an opening in its outer annular wall in Fluid connection is. In the interior of this annular chamber 53, a cylindrical member 55 is arranged, in whose shell four through holes 56 are formed with a round cross-section. The passage openings 56 are each offset by 90 ° to each other about the axial direction, which coincides with the advancing direction 80, respectively. Through the passage openings 56, the gas from the annular chamber 53 can flow radially inwardly into a gap 57 which is between the cylinder member 55 and the cylindrical portion 64 and the frusto-conical portion 62 of the liquid nozzle member 65 is formed. From this intermediate space 57, the gas can in turn flow axially and along the liquid nozzle element 65 into the passage opening 52 of the hole element 51 and thus to the gas inlet nozzle 50.

On the inlet side, the liquid nozzle element 65 has in its frustoconical portion 62 a widened edge 71 on which the liquid nozzle element 65 rests on the upper end face of the cylinder element 55. On its lower end face, the cylinder element 55 in turn rests on the hole element 51. To maintain the device, the annular hole member 51 can be removed from the frame 20, whereby the cylinder member 55 is released axially and can also be removed. As a result, in turn, the liquid nozzle element 65 is released axially.

A frame 20 of a further embodiment of a slot wall milling device according to the invention is shown in FIGS. 3 and 4. 3, the frame 20 on the bottom side a querschnittsverjüngtes milling blade 90, on both sides of the not shown in Fig. 3 cutting wheels are mounted.

The embodiment shown in FIGS. 3 and 4 differs from the embodiment shown in FIG. 2 essentially in that an annular sealing lip 92 is provided in the annular hole member 51, which abuts against the outer wall of the cylindrical portion 64 of the liquid nozzle element 65. If the gas pressure in the gas introduction device exceeds the hydrostatic fluid pressure at the gas inlet nozzle 50, this sealing lip 92 opens and gas can flow out of the annular chamber 53 into the gas inlet nozzle 50 and from there into the slot. However, if the gas pressure in the gas introduction device is lower than the hydrostatic fluid pressure, then the sealing lip 92 closes and the inflow of suspension into the gas introduction device is prevented.

In addition, the gas inlet nozzle 50 of the embodiment of FIG. 4, in contrast to the embodiment of FIG. 2 in its lower region is not cylindrical but cone-shaped.

Claims (10)

1. Method for making a trench wall in the soil, in which

   - a trench wall cutter (10) having at least one on the frame (20) rotatably driven cutting wheel (12, 12') is lowered into the soil (3), whereby soil material located below the cutting wheel (12, 12') is stripped and a cut trench (1) is made, and

   - a settable liquid is supplied into the cut trench (1),
   characterized in that

   - the settable liquid is supplied into the cut trench (1) at the frame (20) in the portion of the cutting wheel (12, 12'), and

   - on the frame (10) in the portion of the cutting wheel (12, 12') moreover a gas, in particular air, is supplied into the cut trench (1) in a defined manner.
2. Method according to claim 1,
   characterized in that
   the flow of the supplied gas and/or of the supplied settable liquid is directed to the cutting wheel (12, 12').
3. Method according to one of claims 1 or 2,
   characterized in that
   the gas is supplied into the cut trench (1) with a flow profile which surrounds a flow profile of the settable liquid in particular in a concentric manner during its supply or which is surrounded by this flow profile in particular in a concentric manner.
4. Method according to one claims 1 to 3,
   characterized in that
   the gas is supplied during the lowering and/or drawing of the trench wall cutter (10), in particular during the operation of the at least one cutting wheel (12, 12').
5. Method according to one of claims 1 to 4,
   characterized in that
   the gas is supplied into the cut trench (1) with a gas pressure which is varied as a function of the current cutting depth of the trench wall cutter (10).
6. Method according to one of claims 1 to 5,
   characterized in that
   due particularly to the cutting wheel action, the settable liquid is intermixed in the cut trench (1) with stripped soil material whilst producing a hardening suspension.
7. Trench wall cutting device for making a trench wall, in particular by means of a method according to one of claims 1 to 6, comprising

   - a frame (20),

   - at least one cutting wheel (12, 12') rotatably supported on the frame (20),

   - a drive (15, 15') through which the cutting wheel (12, 12') can be set into a rotary motion, whereby soil material located below the cutting wheel (12, 12') can be stripped whilst forming a cut trench (1), and

   - a liquid conveying device for suppliying a settable liquid into the cut trench (1),

   characterized in that

   - the liquid conveying device has a liquid supply nozzle (60) which is arranged in the portion of the cutting wheel (12, 12') on the frame (20), and

   - a gas conveying device with a gas supply nozzle (50) which is also arranged in the portion of the cutting wheel (12, 12') on the frame (20)is provided for a defined supply of a gas into the cut trench (1).
8. Device according to claim 7,
   characterized in that
   the gas supply nozzle (50) surrounds the liquid supply nozzle (60) preferably in an annular and/or concentric manner or is surrounded by this liquid supply nozzle (60) preferably in an annular and/or concentric manner.
9. Device according to one of claims 7 or 8,
   characterized in that
   the gas conveying device includes a gas-pressure generating device arranged outside the cut trench (1).
10. Device according to one of claims 7 to 9,
    characterized in that
    the gas supply nozzle (50) and/or the liquid supply nozzle (60) is directed to the at least one cutting wheel (12, 12').

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