EP0640719B1 - Method for stabilising a surface of a soil layer - Google Patents

Abstract

In a method for stabilizing the surface of a soil layer for a track, the ballast beneath a track is continuously taken up and cleaned, while at the same time the surface of a soil layer which has been uncovered beneath the track is mixed with aggregate, levelled and compacted to form a protective layer, after which the ballast is released onto the new protective layer. The aggregate is deposited directly onto the surface of the soil layer and mixed with it beneath the track. <IMAGE>

Description

The invention relates to a method for stabilizing the ground level of a track, wherein the ballast is continuously picked up underneath a track and optionally cleaned, while at the same time the ground level exposed below the track is mixed with additives and leveled and compacted to form a protective layer, whereupon the ballast is applied the new protective layer is thrown off, and a machine for carrying out the process.

It is - according to the generic AT-PS 294 898 - already known a machine for cleaning the ballast from track bedding and at the same time stabilizing the ground level, which has an elongated machine frame mounted at the end on bogies. Approximately in the longitudinal center of this machine frame, a track lifting unit is arranged thereon, upstream of which two basically identical clearing chains, also connected to the machine frame, are arranged in the working direction of the machine. The front of these two clearing chains passed under the track serves to receive the ballast ballast and to throw it into a screening plant, from where the now cleaned ballast is transported back by means of a conveyor and dropped into the track bed via a distributor. The following second clearing chain is intended for removing and picking up the earth level in a certain layer thickness. The excavated earth is transported upwards and falls onto a conveyor belt, which simultaneously transports the bedding residues from the sieve. Subsequently, this material can either be thrown off the track or placed in a conveyor, which can also be loaded via a container containing additives and binders. The resulting mixture of soil, bedding residues, aggregates and binders is laid out in the track bed on a flexible boom in the working direction in front of the discharge point of the cleaned ballast and mixed by means of a motorized rotating body, after which the mass is compacted or stabilized by a vibrating plate. This method is relatively complicated or complex with regard to the machine construction, which also makes it susceptible to faults.

Furthermore, according to EP 0 135 478 A1, a method for stabilizing soft floors for the purpose of improving their load-bearing capacity is known. After removing the layers covering the subgrade, the underlying soil is prepared using the local mixing method, whereby the incorporation of binders such as cement and lime, as well water and reinforcement particles are added.

Finally, GH-PS 595 512 describes a method and / or a device for strengthening the surface of a formation layer. Here, a diffusible hard foam is applied in the unexpanded form on the formation and foamed into a stable, seamless tape.

The object of the present invention is now to provide a method of the type described at the outset or a machine with which better and simplified stabilization of the ground level of a track is possible or the formation of a protective layer can be carried out more quickly and easily.

This object is achieved according to the invention in that the additives are applied directly to the exposed earth level and mixed with it below the track. It is thus possible to mix an upper layer of the formation with the aggregates more quickly directly on the formation with a substantial reduction in the construction effort, so that the work output for a ballast cleaning which is expediently carried out continuously in parallel is in no way impaired. Since the mechanical effort is significantly reduced by the mixing directly on the soil, a conventional ballast bed cleaning machine can be used to carry out the method, which essentially only needs to be equipped with various additional devices in an area between the clearing chain and the ballast discharge and thus is also easy to retrofit.

If, according to a further embodiment of the invention, the uppermost layers of the soil are torn open immediately after the ballast has been removed and the aggregates are introduced into the cracks in the same work step, this ensures particularly good and uniform mixing of the components and increases the effectiveness of the mixing process.

A further development of the method described in claim 3 results in the creation of a rigid plate with a considerable compressive strength of approximately 5 to 7 kg / cm ² . This very stable layer offers an optimal support for the ballast bed of the track to be installed on it. The addition of lime in a concentrated form results in a simplified transport and binds the water contained in the clay as well as any organic substances.

If the method is designed according to claim 4, it ensures, regardless of a different composition of the soil, an optimal and highly uniform setting of the materials forming the protective layer and reliably prevents the mixture from being too dry or too liquid.

If a film of plastic is placed on the compacted protective layer and the cleaned ballast is thrown onto the film, this will desirably provide effective drainage of the ballast bed, the water-impermeable plastic membrane reliably preventing water from entering the existing cracks in the leveling layer from the outset.

The design of a machine according to claim 6 for carrying out the method offers the particular advantage that the facilities required for processing the soil are fixable and usable without influencing the equipment used for ballast cleaning. The arrangement of mixing elements which can be immersed in the earth planum enables a simplified and quick mixing to be achieved without time-consuming absorption and further transport of the uppermost layer of planum to be processed.

The further embodiment of the machine according to claim 7 enables the exposed soil planum to be loosened uniformly and simultaneously over its entire width and, above all, at the desired depth, which can be set differently depending on the requirements and is normally approximately 10 cm.

If the ripping teeth are attached to a support frame of the mixing device, this offers particular robustness with a high load capacity of the device.

With the development of the invention described in claim 9, a possibility is created to mix and machine the earth planum area-wide or over its full width with a relatively simple, back-and-forth device with little structural effort. In addition, the swivel arms with the mixing devices can be easily and quickly transferred from a working to a transfer position by combining a lateral height adjustment with a twist under or over the track.

The further development of the machine as set out in claim 10 combines the process of tearing open or plowing the soil with the simultaneous introduction of required aggregates into the cracks in the soil in an extremely expedient and also time-saving manner.

With the embodiment of the invention described in claim 11, the spraying of the water-lime mixture, which is important for the load-bearing capacity of the sub-base layer, can be accomplished without special technical effort.

If the machine is designed according to claim 12, this enables the mixing device to be inserted and taken out of operation quickly and easily, without the need for time-consuming retooling work on the machine.

The development of the machine according to claim 13 offers the advantage that the freshly mixed soil with the additives can be immediately leveled and compacted into a load-bearing layer, the degree of compaction being precisely adjustable by the height adjustment of the device.

According to a further embodiment of the invention according to claim 14, there are essentially similar advantages as already described in claim 12.

The design of the compacting device described in claim 15 enables the problem-free rolling up of a water-impermeable membrane made of plastic onto the formation protection layer. This membrane can be reinforced on both sides by a polypropylene mesh to increase the tensile strength and covers the entire crown of the formation with a width of approx. 5 m.

A development specified in claim 16 facilitates or simplifies the introduction of the formation protection film in particular in that the work progress is not impaired when the end of a film roll is reached, since the second roll is immediately available for the continuous unwinding of the protection film.

The design of the machine according to claim 17 ensures that the track is raised sufficiently in the entire work area for the unimpeded use of all work aggregates required for ballast clearing and stabilization of the level, while at the same time increasing safety in the work area.

Finally, a further embodiment of the invention according to claim 18 has the advantage of ensuring the uninterrupted workflow while avoiding breaks for the material supply.

The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing.

• Fig. 1 eine Seitenansicht des in Arbeitsrichtung vorderen Teiles eines Gleisbauzuges mit einer erfindungsgemäß ausgebildeten Schotterbett-Reinigungsmaschine mit in Arbeitsrichtung vorgeordneten Abraumverladewagen und unmittelbar hinter einer Räumkette angeordneten Arbeitsaggregaten zum Stabilisieren des Erdplanums,
• Fig. 2 eine Seitenansicht des in Arbeitsrichtung hinteren Teiles des Gleisbauzuges mit Silo- und Tankwagen zum Transport von Zuschlagstoffen,
• Fig. 3 eine vergrößerte Seitenansicht der Schotterbett-Reinigungsmaschine im Bereich der Arbeitsaggregate und
• Fig. 4 eine teilweise Draufsicht auf die erfindungswesentlichen Arbeitsaggregate zum Stabilisieren des Erdplanums.

Show it:

• 1 is a side view of the front part of a track construction train in the working direction with a ballast bed cleaning machine designed according to the invention with overburden loading wagons arranged in the working direction and working units arranged directly behind a clearing chain for stabilizing the ground level,
• 2 is a side view of the rear part of the track construction train in the working direction with silo and tank trucks for transporting aggregates,
• Fig. 3 is an enlarged side view of the ballast bed cleaning machine in the area of the working units and
• Fig. 4 is a partial plan view of the working units essential to the invention for stabilizing the earth level.

1 and 2 shows a track construction train 1 has a centrally arranged machine 2 for ballast bed cleaning with an elongated machine frame 4 mounted on running gears 3, which is equipped with a clearing chain 5 for receiving ballast 6 to be cleaned from a track 7 and for dropping the Gravel is equipped in a screening plant 8. The resulting spoil is transported via a conveyor 9 to a spoil loading system 10, which consists of a number of similar silo wagons 11 connected by means of continuous conveyor belts, which are arranged upstream of the machine 2 in the working direction indicated by an arrow 12. In the area between the ballast pick-up and discharge point or immediately behind the clearing chain 5 there are working units provided for stabilizing an earth level 14, which essentially consist of two mixing devices 15, 16 and a compacting device 17 and which are also shown in FIGS. 3 and 4 be described in detail. Directly downstream of the machine 2 (see FIG. 2) are the loading of the mixing device 15, 16 with additives, silo wagons 18 with a compressor unit 19 and tank trucks 20 with a pump station 21. A workshop wagon 22 forms the end of the track construction train 1.

As can now be seen from FIGS. 3 and 4, the mixing devices 15, 16 are arranged with respect to the working direction directly behind the clearing chain 5 on the machine frame 4 and are approximately mirror images of the longitudinal axis of the machine or track. Each mixing device 15, 16 has a beam-like support frame 24 running in the cross-machine direction. These are detachably connected to each other at their opposite ends, while at the other end on the outside of the machine they are each articulated to a support body 26 via a parallelogram linkage 25. The support bodies 26 are mounted on the machine frame 4 and are designed to be rotatable about a vertical axis by means of a drive 27. Another drive 28 is used to adjust the height of the mixing device 15, 16 relative to the machine frame 4 and is also connected to the support body 26.

On the front side of the support frame 24 in the working direction, trough-shaped tear teeth 29 are provided which lie next to one another in the cross-machine direction and are directed obliquely downwards or forwards. Each tear tooth 29 has a channel 30 which is assigned to an opening 31 in the support frame 24. Via a flexible line 32 and an associated line 33 fastened to the machine frame 4, these openings 31 or the channels 30 can be filled with cement, which is conveyed out of the silo wagons 18 with the aid of the compressor unit 19.

On the side of the support frame 24 opposite the tear teeth 29 in the longitudinal direction of the machine, a horizontal swivel arm 34 is provided for each longitudinal side of the machine, which is mounted on the support frame 24 via a vertical axis 35. By means of a drive 36, the free end of each swivel arm 34 can be swiveled back and forth in a horizontal plane and thus covers approximately half of the earth level 14. Along the swivel arm 34, spray nozzles 37 are arranged on the underside of the earth, which have a flexible line 38 and an associated line 39 fastened to the machine frame 4 are connected to the tank truck 20 and can be fed by means of the pump station 21. The free end of each swivel arm 34 is equipped with downwardly projecting mixing elements 40 which can be rotated about a vertical axis 42 by means of a drive 41.

The compacting device 17 is located behind the mixing device 15, 16 in the working direction and has a horizontal compacting plate 43 which extends in the transverse direction of the track and is formed in two parts 44, 45 which can be releasably connected to one another. The outer ends of the compressor plate 43 are each articulated via a parallelogram linkage 46 on a longitudinal side of the machine frame 4, with a drive 47 for the height adjustment the compression device 17 is used opposite the machine frame 4. Furthermore, the compacting device 17 is provided with a holder 48 which is provided for receiving three film rolls 49. The latter are arranged one behind the other with respect to the longitudinal direction of the machine and are aligned with their axis of rotation 51 in the transverse direction of the machine and contain the plastic film 50 to be rolled onto the stabilized earth planum 14. The machine 2 is also equipped with two lifting units 52, which raise the track 7 in the area of the working units in a raised position hold on and enable the unhindered use of all units.

The operation of the machine described is as follows:

The conventional clearing chain 5 arranged below the track 7 removes the ballast 6 from the track bed with continuous work priority and thus exposes the ground level 14. By acting on the drives 27, 28, 36, 47, the ripping teeth 31, the swivel arms 34 and the compressor plate 43 are pivoted into the working position below the track. The earth planum 14 is loosened by the subsequent tear teeth 29 of the mixing device 15, 16 to a depth of preferably about 30 cm, cement being simultaneously introduced through the channels 30 into the furrows of the loosened earth planum or being blown in by means of the compressor unit 19. Thereupon, lime concentrate mixed with water, which is mixed with water, is applied to the ground level 14 by means of the pump station 21 via the spray nozzles 37. In the event that the composition of the soil is precisely known from appropriate samples, the cement and lime requirements can be varied automatically so that - regardless of the different composition of the soil - a homogeneous, equally resilient protective layer is always created. Furthermore, the moisture content of the soil can be measured in the area of the plowed earth planum and, accordingly, the amount of water to be added can be determined. The resulting mixture of earth, cement, lime and water is now mixed in place by the rotating mixing elements 40, with the drive 28 being able to precisely control both the thickness of the layer to be mixed and the depth of penetration of the tear teeth 29 or via a control device 53 is adjustable. Subsequently, the compression of the upper formation layer is carried out by the compression device 17. The degree of compression can be controlled using the drive 47. The slope of the formation surface required for proper drainage of the formation is automatically created by a corresponding inclination of the mixing devices 14, 15 and the compression device 17. The water-impermeable plastic film 50 is deposited on the now stabilized formation protection layer by a film roll 49 in the entire width of the earth formation 14, to which the cleaned ballast 13 can be pivoted back and forth Ballast straps 55 is dropped. If the entire film is unrolled from a film roll, work can continue with the second roll located on the holder 48. A sufficient number of additional film rolls 49 are carried on a loading surface 54 on the machine 2 during use.

Claims (18)

1. A method for stabilising the soil formation of a track, in which the ballast is continuously taken up underneath a track and cleaned as necessary, while at the same time the exposed soil formation underneath the track is mixed with additional materials and is levelled and consolidated, forming a protective layer, whereupon the ballast is discharged onto the new protective layer, characterised in that the additional materials are applied directly to the exposed soil formation and are mixed with the said soil formation underneath the track by the penetration therein of mixing elements.
2. A method according to claim 1, characterised in that immediately following the removal of the ballast, the topmost layers of the soil formation are broken up by means of ripper teeth, and in the same procedure the additional materials are introduced into the gaps.
3. A method according to claim 2, characterised in that first, cement is introduced into the gaps in the soil formation and if necessary a mixture of water and lime is sprayed onto the surface of the soil formation, whereupon the topmost layer of the soil formation, provided with cement and, if necessary, with lime, is intermixed, graded and consolidated.
4. A method according to one of claims 2 or 3, characterised in that the moisture content of the ground in the region of the broken-up soil formation is continuously measured and the quantity of water to be added is automatically regulated in dependence thereon.
5. A method according to one of claims 1 to 4, characterised in that a film made of a plastics material is laid on the consolidated protective layer and the cleaned ballast is discharged onto the film.
6. A machine for creating a formation protective layer of a track, comprising an excavating chain (15) [sic, recte 5] for taking up the ballast underneath the track, conveyor units for discharging the ballast, and devices (32;15,16) for conveying additional materials and intermixing them with the soil formation, for implementing a method according to one of claims 1 to 5, characterised in that, between the excavating chain (5) and the mixing elements (40) of the mixing device (15,16), openings (31) of a supply line (32) which are located underneath the track are provided for conveying the additional materials onto the soil formation.
7. A machine according to claim 6, characterised in that, immediately preceding the mixing device (15,16) in the working direction, a number of ripper teeth (29) are provided which are located side by side in the transverse direction of the machine, are vertically adjustable by means of drives (28) for positioning underneath the track (7), and are mounted on a machine frame (4).
8. A machine according to claim 6 or 7, characterised in that the ripper teeth (29) are fixed on a supporting frame (24) of the mixing device (15,16).
9. A machine according to one of claims 6, 7 or 8, characterised in that the mixing elements (40) are mounted on a horizontal swivelling arm (34) so as to be rotatable by means of a drive (41) around a vertical axis (42), the end of the said swivelling arm opposite the mixing elements being fixed to the supporting frame (24) of the mixing device (15,16) so as to be pivotable around a vertical axis (35) by means of a drive (36).
10. A machine according to one of claims 6 to 9, characterised in that each of the ripper teeth (29) has a duct (30) provided with each opening (31), for conveying an additional substance therethrough, the said duct being connected via the flexible line (32) to a supply line (33) fixed to the machine frame (4).
11. A machine according to one of claims 6 to 10, characterised in that the mixing device (15,16) has spray nozzles (37), arranged one after another on the swivelling arm (34) in the longitudinal direction thereof, which are connected by a flexible line (38) to a supply line (39) fixed to the machine frame (4).
12. A machine according to one of claims 6 to 11, characterised in that a mixing device (15,16) is provided on each longitudinal side of the machine and is connected by means of a parallelogram linkage (25) to a supporting body (26) which is mounted on the machine frame (4) so as to be rotatable around a vertical axis by means of a drive (27).
13. A machine according to one of claims 6 to 12, characterised in that, following the mixing device (15,16) and preceding the ballast discharge point in the working direction, a consolidating device (17) is provided which is vertically adjustable by means of drives (47) for positioning underneath the track (7) and is equipped with a horizontal consolidator plate (43) which extends approximately in the transverse direction of the track.
14. A machine according to one of claims 6 to 13, characterised in that the consolidator plate (43) comprises two parts (44,45), each arranged via a parallelogram linkage (46) on one longitudinal side of the machine frame (4), the said two parts being detachably joined together.
15. A machine according to one of claims 6 to 14, characterised in that a holder (48) which is connected to the consolidating device (17) and located following the consolidator plate (43) in the working direction of the machine is provided for supporting a roll of film (49) extending over the whole width of the formation and containing the plastic film (50), the axis of rotation (51) of the roll of film (49) extending substantially parallel to the surface of the formation and in the transverse direction of the track.
16. A machine according to claim 15, characterised in that the holder (48) is designed to hold three rolls of film (49) at the same time, arranged following one another in the longitudinal direction of the machine (2).
17. A machine according to one of claims 6 to 16, characterised in that in addition to a first lifting unit (52) for lifting the track (7), which is arranged in the region immediately following the excavating chain (5), a further, second lifting unit (52) is provided which is arranged on the machine frame (4) in the region between the mixing device (15,16) and the consolidating device (17).
18. A machine according to one of claims 6 to 17, characterised in that the machine (2) has a loading surface (54) for carrying a number of additional supply rolls of plastic film.

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