EP0496981B1 - Apparatus for laying pipelines without excavation - Google Patents

Abstract

Apparatus for laying pipelines without excavation in earth which is not rocky, consisting of a drawn clearing head (1) with passage openings (8) for the earth and a follow-up pipe (12; 27; 28, 29; 38) connected to it. The clearing head preferably consists of a first pipe (2, 18) of smaller diameter and a concentric second pipe (3, 19) of larger diameter surrounding the first pipe (2, 18). The diameter of the second pipe (3, 19) corresponds to the diameter of the bore for the pipeline to be laid. The first pipe and the second pipe are connected to one another by at least three radially arranged webs (4, 20). A hauling rope running through a pilot bore (30) or a pneumatically driven percussion drilling device, which provide for the advance of the clearing head with the follow-up pipe, can be hung in the clearing head. <IMAGE>

Description

The invention relates to a device for trenchless laying of pipes in soft soil with a clearing head from a first pipe of smaller diameter, a second, concentric pipe with a diameter corresponding to the diameter of the bore for the pipes to be laid and the two pipes connecting passage openings for the soil forming webs, sharpened in the direction of advance.

Such a device, which at the same time serves to destroy already laid pipelines which are to be replaced by a new pipeline, is described in European patent application 0 368 079.

Pipelines can be laid in soft soil by, for example, running a pneumatically operated ram boring machine, as described in German Offenlegungsschrift 21 57 259, through the soil and pulling a pulling pipe with it. These ram boring machines are manufactured with different diameters, from 45 go up to 180 mm in diameter. By Attachment of an expansion cone allows pulling pipes with a larger diameter than the diameter of the ram boring machine to be pulled through the earth, however, the diameter of the pulling pipes is limited by the fact that the soil can only be displaced and compressed to a limited extent and the propulsion resistance is increased considerably by the expanding cone becomes. Taxes are not possible.

Should pipes of significantly larger diameter through the soil brought, a plug-on cone is placed on the rear end, which serves as an adapter for a ram boring machine attached to it, so that the pipe is hammered into the ground, whereby an earth core migrates back into the pipe during the advance and can exit through openings in the plug-on cone. This method is e.g. B. described in German Offenlegungsschrift 34 26 374. It is disadvantageous here that the pipes have to be very stable because of the blows exerted on them from the rear end and therefore have a large wall thickness. This process is also one of the non-taxable.

Furthermore, it is known to first produce a pilot hole using a ram boring machine that is direction-controlled. The pilot hole is then widened and a pipeline is installed in it.

In this case, too, the restrictions apply when tightening with an expanding cone. When driving in or pushing in a pipe with a large diameter from the rear end, a pilot hole cannot be used to guide the pipe in the correct direction.

German utility model 87 14 724 describes a device for replacing pipes laid in the ground in the course of a pipeline, with which an old pipe is removed and a new pipe is pulled in its place, for which very great tensile forces have to be applied. It is usually around existing pipes and the new pipe to be installed should follow the course of the existing pipe. This publication does not provide any information as to how a directionally accurate laying - possibly on a curved path - can be guaranteed. At the end of the new pipe, a cap is attached, which is connected to a pull rod and via which a compressive force is applied to the new pipe either directly or indirectly via a piston-cylinder unit. Likewise, the old pipe is pushed through the pull rod, which acts on an adapter at the end of the old pipe. Block-like webs with smooth outer surfaces are arranged between concentric, ring-shaped projections, which form triangular through openings for the soil between them. The webs and the annular projections form a conical adapter with a diameter that corresponds to the straight outer surfaces of the webs. The larger diameter is noticeably larger than the outer diameter of the pull pipe, so that with this device a considerable amount of compaction work has to be carried out in order to displace the soil and to ensure that the adapter with the pull pipe can be pulled through the soil.

Since this known device simultaneously removes an old tube and introduces a new tube, it is obvious that large differences in diameter between the old tube and the new tube can neither be intended nor possible. To make it easier to remove the old pipe and insert a new pipe, the soil should be in the area of the adapter loosened and caused to fall through the slots between the webs into the pipeline. For this purpose, nozzles are provided, which open between the webs, via which compressed air or another flowable medium such as water is to be supplied.

That this measure for removing an old pipe and inserting a new pipe is not sufficient, since the main jacking resistance comes from the old pipe, can be seen from German Offenlegungsschrift 39 40 354, which describes that an old pipe is first placed in the longitudinal direction at two opposite points is slashed, after which a ram boring machine with a cutting ring attached is passed through the old pipe in order to detach the old pipe from the surrounding earth and to create a cavity around the old pipe.

It can also be seen from German patent specification 39 03 864 that the main problem when replacing old pipes with new ones is removing the old pipe. In this known device, a cutting caliber is articulated to a widening caliber, the cutting caliber being pulled through and smashing the old pipe, while the widening caliber serves to widen the bore to such an extent that a pulling pipe connected to the widening caliber can be easily pulled in. A compensating pipe is arranged between the expansion caliber and the new pipe string, with which the new pipe string is connected in a sliding and sealing manner. The seal is intended to break in the ground or penetrate groundwater into it Prevent new pipe.

The invention has for its object to lay pipes - possibly curved - relatively large diameter trenchless and accurate, without it being necessary to use a ram boring machine, a hydraulic press or the like of the same large diameter.

Based on this task, it is proposed in a device of the type mentioned that, according to the invention, the front end of the second tube is tapered from the outside diameter to the inside diameter and the front end of the first tube is tapered from the inside diameter to the outside diameter in the direction of advance, the first tube and the second tube are axially sharpened are arranged offset from each other so that the rear end of the first tube ends in the region of the front end of the second tube and the webs are only so wide that stones with a size corresponding to the difference in diameter between the first tube and the second tube between the webs in can reach the inside of the pull tube and that the pull tube is connected to the drawn clearing head via a joint.

The clearing head can either make a pilot hole itself or is made by one previously Pilo holes pulled. The action of a certain tensile force on the clearing head tip and the joint between the clearing head and the pulling pipe ensure that the clearing head always follows the pilot hole.

Because the pulling pipe is pulled through the clearing head, only the outer casing friction of the bore and the inner friction of the soil passing through the pipe occur in the pulling pipe. No soil needs to be displaced or compacted for the draw tube, so that this work does not have to be applied during the driving.

• die Kraft, die für das Herstellen der Pilotbohrung erforderlich wäre und
• die Zugkraft zur Führung des Rammbohrgerätes in der Pilotbohrung (z. B. über Bohrgestänge, kleine Winde) zusätzlich zum Ziehen des Räumkopfes zur Verfügung.

The clearing head can be pulled directly through a ram boring machine inserted into it, which has a considerably smaller diameter than the clearing head. This ram boring machine creates a hole for itself at smaller distances by displacing and compacting the soil, or it is pulled through larger distances through a pilot hole previously made. Stand here

• the force that would be required to produce the pilot hole and
• the pulling force for guiding the ram boring machine in the pilot hole (e.g. via drill rods, small winch) is also available for pulling the clearing head.

At the same time, during the advance, the soil enters the interior of the pulling pipe through the openings in the clearing head and migrates backwards in the pulling pipe.

A pulling rope can also be suspended in the clearing head, which is guided through the pilot hole previously made. In this case, the clearing head with the pulling pipe is pulled through the soil by means of the pull rope and a large winch connected to it.

The drilling device used for the pilot drilling can advantageously be designed as a direction-controllable drilling device, in order to be able to carry out drilling precisely over large distances.

The propulsion and the entry of the soil are facilitated by the passage openings in the pull pipe, since the second pipe is shorter than the first pipe in the driving direction and the webs are bevelled from the first pipe to the second pipe. These diagonally running cutting knives reduce the total cutting resistance considerably, the floor cannot become tense and there is no vault.

The clearing head with the pull pipe does not get stuck when there are larger stones on the way, since the first pipe and the second tube is axially offset from one another such that the rear end of the first tube ends in the region of the front end of the second tube. In this way it is ensured that the passage opening is at least so wide that stones with the diameter corresponding to the difference in diameter between the first tube and the second tube can get between the webs into the interior of the pull tube. Even larger stones are displaced outwards by the oblique cutting edges of the webs and therefore do not hinder the advance as much as stones that settle between the webs and prevent the penetration of the soil through the through openings into the interior of the pipe.

At least three webs can preferably be arranged radially and sharpened in the direction of distribution.

So that the clearing head can easily follow the pulling direction of the ram boring machine or rope, the joint connecting the look-up pipe to the cutting head can preferably consist of an outwardly directed collar on the rear end of the second pipe of the clearing head and an inwardly facing collar overlapping it with axial play Draw tube exist. The collar on the pulling tube can be produced in the simplest way from an inwardly projecting welding bead which is applied after the pulling tube is directed over the outward-pointing one The collar on the clearing head is pushed.

If the protrusion of such a welding bead is not sufficient, the collar on the inspection tube can also consist of a wire ring welded to the front edge, which, if slotted, can be slipped over the outwardly facing collar at the rear end of the drawing tube and then with the Check pipe is connected by welding.

In the case of a polyethylene draw tube, the inward collar can consist of notches distributed over the circumference.

To retract the pull tube and the passage of the To facilitate soil through the pull pipe, a lubricant can be supplied to the clearing head via a lubricant line and corresponding outlet nozzles. This lubricant is preferably made of bentonite.

Fig. 1

einen Längsschnitt durch einen Räumkopf mit angehängtem Nachziehrohr und eingesetztem Rammbohrgerät,

Fig. 2

eine Vorderansicht der Fig. 1,

Fig. 3

eine Verbindung des Räumkopfes nach Fig. 1 mit dem Bohrgestänge der Pilotbohrung,

Fig. 4

einen Längsschnitt eines durch ein Zugseil gezogenen Räumkopfs mit angehängtem Nachziehrohr und

Fig. 5

eine Anhängung eines Nachziehrohres aus Polyäthylen an den Räumkopf nach Fig. 4.

The invention is explained below with reference to several exemplary embodiments shown in the drawing. The drawing shows:

Fig. 1

a longitudinal section through a clearing head with attached pulling pipe and inserted ram boring machine,

Fig. 2

2 shows a front view of FIG. 1,

Fig. 3

a connection of the clearing head of FIG. 1 with the drill string of the pilot bore,

Fig. 4

a longitudinal section of a clearing head pulled by a pull rope with attached pulling tube and

Fig. 5

an attachment of a pull pipe made of polyethylene to the clearing head according to FIG. 4.

A clearing head 1 consists of a first pipe 2, around which a second pipe 3 of larger diameter is arranged concentrically. The tubes 2, 3 are by at least three, or how shown, connected to each other by four radial webs 4. The inner tube 2 is longer than the outer tube 3 and protrudes in the direction of advance. Accordingly, the webs 4 have obliquely running and sharpened edges 5. The pipes 2, 3 also have sharpened front ends 6, 7, which facilitates penetration into the ground. Through openings 8 are formed between the webs 4. In the rear area of the outer tube 3, a shoulder 9 is formed, which is followed by an extension 10. This extension 10 ends in a radially outwardly directed collar 11. This collar 11 is overlapped by the front end of a pull tube 12. A welding bead 13 is arranged along the front edge of the draw tube 12, which forms an inward collar and engages over the outward collar 11. In this way, an articulated connection between the clearing head 1 and the pulling tube 12 is created, which can be easily produced on site. The clearing head 1 can be detached from the pulling tube 12 just as easily by grinding the welding bead 13 by means of a suitable grinding device. A ram boring machine 14 is arranged in the inner tube 2 and is supported with a collar 15 at the rear end of the inner tube 2. This ram boring machine 14 can be constructed as described in German Offenlegungsschrift 21 57 259. If compressed air is supplied to this ram boring machine 14, a percussion piston arranged in the ram boring machine 14 starts to move and drives the ram drilling machine through the soil by displacing and compacting it. The ram boring machine 14 pulls the clearing head 1 and the pulling pipe 12.

In Fig. 3 it is shown how at larger distances the ram boring device inserted into the clearing head is pulled by means of the drill rod 17 used for the pilot bore 16.

In the embodiment shown in FIG. 4, the broaching head 1 also consists of an inner tube 18 and an outer tube 19 - here double-walled, as a result of which a cavity for adding bentonite is formed - which are connected to one another via at least three radially arranged webs 20. The inner tube 18 also has a too sharpened front end 21. The rear end 22 of the inner tube 18 ends at a distance from the sharpened front end 23 of the outer tube 19. In this way, passage openings are created between the inner tube 18, the outer tube 19 and the webs 20 that are large enough to also allow the passage of Allow stones.

In this case too, the outer tube 19 merges via a shoulder 24 into an extension 25 with a radially outwardly directed collar 26. The drawing tube shown consists of an inner steel tube 27, a polyethylene coating 28 and a concrete jacket 29, which serves to protect the coating during the pulling into the ground.

A wire ring 37 is welded to the front end edge of the steel tube 27 and engages behind the outwardly directed collar 26 on the extension 25 of the outer tube 19. By welding the wire ring 37 in, larger diameter differences can be achieved bridge between the collar 26 and the steel tube 27.

In order to facilitate the retraction of the tube, a suitable lubricant, for. B. bentonite. This bentonite can also wet the inner wall of the outer tube 19 and the steel tube 27 in a manner not shown, in order to facilitate the passage of the tube through the soil that has entered.

FIG. 4 shows a pilot bore 30 which is produced in a known manner before the draw tube 27, 28, 29 is drawn in by means of the clearing head 1. When the pilot bore 30 is made, a traction cable 31 is pulled, which can be attached to the clearing head 1 by means of an auxiliary construction 32 with collar 33 according to the dimensions of a ram boring machine and a shackle 34. After completion of the pilot bore 30, the clearing head 1 with the attached pulling pipe 27, 28, 29 is pulled through the soil by means of the rope 31 and a winch acting thereon.

This method has the advantage that the pilot bore 30 can be produced relatively quickly and precisely by a direction-controlled ram boring machine or a corresponding device and the clearing head 1 with the pulling tube 27, 28, 29 can no longer run when it is pulled through by means of the traction cable 31 Soil is pulled.

The drawing tube 38 shown in FIG. 5 consists of Polyethylene. Grooved pins 39 distributed over the circumference engage behind the outwardly directed collar on the extension of the clearing head.

Claims (11)

1. Device for the trenchless laying of pipelines (12; 27, 28, 29; 38) in soft soil with a broaching head (1) consisting of a first pipe (2, 18) of a relatively small diameter, a second concentric pipe (3, 19) of a diameter which corresponds to the diameter of the hole for the pipeline (12; 27, 28, 29; 38) to be laid and ribs (4, 20) which connect the two pipes, form through-openings (8) for the soil and are tapered in the advance direction, characterised in that the front end (7, 23) of the second pipe (3, 19) is tapered from the outside diameter to the inside diameter and the front end (6, 21) of the first pipe (2, 18) is tapered from the inside diameter to the outside diameter in the advance direction, the first pipe (18) and the second pipe (19) are axially staggered such that the rear end (22) of the first pipe (18) ends in the area of the front end (23) of the second pipe (19) and the ribs (4, 20) are only so wide that stones of a size corresponding to the difference in diameter between the first pipe (2, 18) and the second pipe (3, 19) can pass between the ribs (9, 20) into the interior of the hauled pipe (12; 27, 28, 29; 38), and that the hauled pipe (12; 27, 28, 29; 38) is connected to the pulled broaching head (1) via a hinged joint (11, 13, 26, 37, 39).
2. Device according to claim 1, characterised in that at least three ribs (4, 20) are arranged radially and tapered in the advance direction.
3. Device according to claim 2, characterised in that the second pipe (3, 19) is shorter in the advance direction than the first pipe (2, 18) and the ribs (4, 20) are bevelled towards the rear from the first pipe (2, 18) to the second pipe (3, 19).
4. Device according to one or more of claims 1 to 3, characterised in that the hinged joint consists of an outward directed collar (11, 26) at the rear end of the second pipe (3, 19) of the broaching head (1) and an inward directed collar (13; 37, 39), which engages over the collar (11, 26) with axial clearance, on the hauled pipe (12; 27, 28, 29; 38).
5. Device according to claim 4, characterised in that the collar on the hauled pipe (12) consists of a welding bead (13).
6. Device according to claim 4, characterised in that the collar on the hauled pipe (27, 28, 29) consists of a wire ring (37) welded to the front edge.
7. Device according to claim 4, characterised in that the collar on the hauled pipe (38) consists of grooved pins (39) distributed over the circumference.
8. Device according to one or more of claims 1 to 7, characterised by a traction cable (31) which is suspended in the broaching head (1) via an auxiliary construction (32) with a collar (33) and a shackle (34).
9. Device according to one or more of claims 1 to 7, characterised by a pneumatically operated driving boring tool (14) which is suspended in the broaching head (1).
10. Device according to one or more of claims 1 to 7, characterised by a driving boring tool (14) which is suspended in the broaching head (1) and is pulled along by means of the boring rod (17) used for the pilot hole (16).
11. Device according to one or more of claims 1 to 10, characterised by a lubricant line (35), which extends to the broaching head, and outlet nozzles (36) in the outer surface area of the outer pipe (19).

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