EP2085567A1 - Method for laying piping without digging - Google Patents

Abstract

The method involves guiding a controlled pipe drive from a starting point (1) under an obstacle (9) to a target point (3). A drilling head (6) is pushed forward from the starting point in the direction towards the target point using support pipes (11). A borehole (12) is expanded to its final diameter and supported by the support pipe, and the soil released by the drilling head is transported out of borehole. A pipeline (14) prepared in partial segments is coupled to a support pipe run (8) formed by the support pipes. The pipeline advances through the borehole by applying compressive forces.

Description

The invention relates to a method for trenchless laying of pipelines, in which from a starting point, a controlled pipe jacking is guided under an obstacle to a target point.

There are numerous methods and devices for laying pipes in the ground without trenching. This can be used to undercut areas on the terrain surface where laying in an open trench would be impossible, unfavorable or too expensive for a variety of reasons. Examples include water bodies, wetlands, rocks, nature reserves, a large installation depth, a high groundwater level or dense development.

Such methods are for example in D. stone "trenchless line construction", Ernst & Sohn publishing house for architecture and technical sciences GmbH & CO. KG, Berlin, 2003 (ISBN 3-433-01778-6 ). The methods may be classified by controllability (controlled or uncontrolled), soil treatment (soil displacement or soil removal), removal of cuttings (mechanical or hydraulic) or number of operations (pilot drilling, expansion drilling, retraction or insertion). Furthermore, for example, the basic geometric design of the drilling axis (straight or curved) or the material of the pipeline to be laid (eg concrete, polyethylene, ductile cast iron, steel, etc.) can be taken as distinguishing features. Another criterion for the classification are the achievable bore dimensions, in particular the length and the diameter of the bore. In many cases, the methods can also be distinguished according to the arrangement of the start or target point, which are arranged, for example, in a shaft, an excavation pit or on the terrain surface. In many cases, a method is only suitable for certain soils or groundwater levels.

The controlled horizontal drilling technique (HDD, "Horizontal Directional Drilling", Spülbohrverfahren) is a previously known method, which is carried out in three phases. After a pilot hole and an expansion hole, high tensile pipes (e.g., steel, polyethylene, or cast iron) are drawn into the wellbore thus created. In this case, distances of over 2000 m can be bridged, with pipe diameters of up to approx. 1400 mm.

Although the controlled horizontal drilling technique has proved to be a reliable method with suitable ground formations, there are some disadvantages. For example, large work areas of a few thousand square meters must be provided to carry out work on both sides of the obstacle to be crossed, which is not always possible or disadvantageous for ecological reasons.

Furthermore, the HDD process causes problems for larger wells (eg, greater than 800 mm diameter) in some soils (especially gravelly, gravelly or stony soils with few cohesive fractions) because the wellbore is not supported prior to drawing in the tubing, but can only be solidified with a pumped drilling fluid. As a result, the required stability is often not achieved, which has collapses. In the HDD technology, it is also unfavorable that when drilling through solid ground Very high torque must be transferred to the drill head, which can lead to breakage of the drill string. Also, because of the mentioned danger of an unstable borehole wall, the borehole diameter must be generally about 1.3 to 1.5 times larger than the diameter of the pipeline to be laid, which leads to additional costs.

Another known method is microtunneling (MT). In this case, a controlled and possibly also curved bore is guided from a launch shaft or a launch pit to a destination shaft or a target pit. The pilot hole, the expansion hole and the insertion of the tubes are done in a single step. The pipes are laid as jacking pipes, which are not connected to each other with tensile strength, because the pipe jacking from the starting shaft or the starting pit is carried out under pressing. With this method, bore lengths of more than 500 m and borehole diameter of more than 2000 mm can be realized.

In the microtunneling process, it is a high cost that the jacking pipes, which are usually made of concrete, remain in the borehole, even if no concrete pipeline is desired. In this case, the introduced concrete pipes can only serve as an empty pipe for an additional pipe to be introduced with product pipes. The use of steel or polyethylene pipes is possible with microtunneling but unusual due to technical difficulties. Thus, pipes made of polyethylene have only a low compressive strength, which limits the laying range. Steel pipes must be inserted and welded together pipe by pipe in the region of the starting point, which is time-consuming and complicated because of the required precise alignment and centering and also requires an interruption of the drilling activity. For pressure pipes such a laying technique is special problematic because the welds before laying can not be subjected to a pressure test.

In the pilot tube propulsions, a controlled pilot bore having a relatively small diameter is firstly carried out, which is then widened in a further step to the desired final diameter of a borehole, at the same time the pipeline to be laid being pushed in from a starting shaft or pulled in from a target shaft. This method is generally limited to bore lengths less than 100 meters, with the hole being straight. The diameters of the pipes to be laid are in the range of about 100 mm to 1000 mm.

In another method, elements of the microtunnelling technique are combined with the one-piece product tube feeder of the HDD technique in such a way that a microtunnelling machine is mounted at the top of the product tube to be installed (pipeline). This procedure is in the DE 10 2006 020 339 A1 described. With the help of a pusher, the prefabricated product pipe string with the microtunnelling machine is pushed from the starting pit to a target point at the top through the ground. This method allows a fast laying of the pipeline, as the set-up times during the feed process are significantly reduced.

A disadvantage of the DE 10 2006 020 399 A1 known method is that pipes made of steel are difficult to control, which is why such a propulsion usually has to provide a planned straight laying. Furthermore, no intermediate pressing stations (Dehnerstationen) can be installed in the product pipeline. As a result, the driving length is limited; Experience is available up to about 500 m. Further, no lubricating nipples for continuous lubrication of the pipe outer wall can be arranged on the product pipe string. thats why a reduction in the skin friction only limited possible, which also adversely affects the maximum bore length of the process.

From the DE 10 2005 021 216 A1 a method for trenchless laying of pipelines is known, in which from a starting point, a controlled pipe jacking is guided under an obstacle to a destination point. In this case, starting from the starting point, a drill head with the aid of support or jacking pipes is advanced in the direction of the target point, wherein the hole produced thereby is already expanded to its final diameter and supported by the jacking pipes. The soil loosened by the drill head is hydraulically conveyed out of the borehole. When the leading end of the jacking pipe string has reached the target point, there is coupled by means of a connecting pipe one end of a prefabricated on the side of the target point pipe (product pipe string) to the end of the jacking pipe string. Subsequently, the strand of the tension-connected interconnecting jacking pipes is withdrawn to the starting point, wherein the product pipe string is drawn into the wellbore.

This method is very advantageous because pre-assembled pipelines with a diameter of approx. 800 mm to 1400 mm can be laid over large laying lengths (approx. 250 m to 750 m) in almost all types of soil and also in the groundwater area in a curved borehole whose wall is supported in all stages of the process. However, both the jacking pipe string and the product pipe string must be tension resistant. Further, in the area of the target point, a larger area is required to prepare the product pipe string there, which may be disadvantageous depending on the circumstances.

It is an object of the invention to provide a method for trenchless laying of pipelines, which makes it possible Relatively large diameter pipelines (eg in the range of 800 mm to 1400 mm) can be laid inexpensively over relatively long laying lengths (eg in the range from 250 m to 750 m), even in difficult soil types (such as gravel, gravel or rock).

This object is achieved by a method for trenchless laying of pipelines with the features of claim 1 and by a method having the features of claim 17. Advantageous embodiments of the invention will become apparent from the dependent claims.

In the method according to the invention for trenchless laying of pipelines, controlled pipe jacking is guided from a starting point under an obstacle to a destination point. In this case, a drill head is advanced starting from the starting point with support tubes in the direction of the target point. The hole produced in this process is already expanded in this step to its final diameter and supported by the support tubes. The soil released from the drill head is conveyed out of the wellbore, e.g. hydraulically. A pipeline prepared at least in sections is then coupled to the support pipe string formed from the support pipes and moved through the borehole, the support pipes again emerging from the borehole.

When moving the pipeline, the pipeline is advanced according to the invention under the exertion of compressive forces through the wellbore. If the support pipe string is not only pressure-resistant (in the axial direction), as required for advancing the support pipes, but also tensile, the introduction of the pipeline can be supported by additional tensile forces are exerted on the pipeline via the support pipe string (see below); but this is only an option. Basically, the inventive method namely using Support tubes are performed, which are designed only for the transmission of axial compressive forces. Such support tubes are usually made of concrete and are much cheaper than tension-resistant support tubes or jacking pipes, as in the above-mentioned method according to DE 10 2005 021 216 A1 be used.

It is advantageous if the pipeline is already assembled in long sections or even in their overall length. For steel pipes, e.g. the joints are welded, optionally sealed and checked. Other quality controls are also possible, e.g. a pressure test. In this state, the pipeline can be stored on a roller conveyor.

In an advantageous embodiment of the method, after being coupled to the support pipe string, the pipe pushes the support pipe string through the borehole. In this case, the propulsion force for advancing the pipeline (axial pressure) can be applied with a pusher over the lateral surface of the pipeline. Such thrusters are known. They are located to the side of the pipeline or surround the pipeline and engage on the outside of the pipeline eg via a collar. With such pushers, it is possible to advance the pipeline continuously or quasi-continuously. Such thrusters can also be in the from the DE 2005 021 216 A1 use known methods advantageous.

It is conceivable to use support tubes in short lengths, with the respective next support tube being attached to the already existing support tube strand at the starting point when the respective rearmost support tube has been advanced far enough. But it may be more advantageous to prefabricate the support pipe, at least in larger sections. Because this allows one Pre-assembly of the piping necessary for the operation of the drilling equipment, monitoring equipment, lubrication equipment (see below) and intermediate compression stations (see below). As a result, set-up times during the drilling process can be reduced to a minimum. In the case of short support tubes, the thrust forces can be applied via the end-side end face, while in the case of a prefabricated support tube strand, the propulsion force for advancing is preferably applied via the lateral surface. For this example, the same pusher can be used with which then the pipe is advanced, as already explained.

In principle, the pipeline can be coupled to the rearmost support tube of the support tube strand by simply abutting the end faces. However, it is more advantageous to use a connecting tube for this, with which a more uniform distribution of force can be achieved and with which, if necessary, tensile forces can be transmitted.

If necessary, short lengths of pipe (e.g., about 2.5 meters long) may be installed with articulated pipe joints, allowing for good controllability. This applies both to the support pipe string and to the pipe (product pipe string).

The pipeline, that is, the product pipe string, can be prepared in the method according to the invention on the side of the starting point and moved starting from the side of the starting point into the borehole. This can be opposite to that from the DE 10 2005 021 216 A1 bring considerable advantages to previously known methods, in particular if there is insufficient space at the destination point to prepare the pipeline, or if, for other reasons, it is more advantageous to focus on the laying activities in the area around the starting point.

In this case, the tubing may be coupled to the support tubing after the boring head has reached the target point. Thus, the support pipe string extends over the entire path from the starting point to the destination point. But it may also be useful to couple the pipe to the support pipe string before the drill head has reached the target point. In this case, the support pipe string is shorter, which saves working time, but the hole is not yet produced in its full length and the connected pipe must be transmitted on the support pipe string possibly greater compressive forces. This variant is suitable e.g. at relatively soft ground.

Alternatively, in the method according to the invention, the pipeline may also be prepared on the side of the target point and moved into the borehole from the side of the target point, the pipeline being coupled to the support pipe string after the boring head has reached the target point. This is similar to the one from the DE 10 2005 021 216 A1 known methods, but in contrast, the pipeline is not moved by pulling from the starting point, but by pushing from the target point through the wellbore. For this purpose a similar (or even the same) pusher may be used as for advancing the support tubes from the starting point. Whether it is better to bring the pipeline from the starting point or from the target point into the borehole depends on the individual case.

As far explained so far, pressure forces are exerted on the product pipe string from the starting point of pressure forces on the support pipe string and from the starting point or from the target point of pressure forces. But it is also conceivable to provide a traction device with which a tensile force can be exerted on the support pipe string after it has reached the target point. In order to make this possible, the individual support tubes in the support tube strand not only have to be pressure-resistant, but also tensile and be connected to each other tensile strength. Furthermore, the mentioned connecting pipe should be able to transmit tensile forces. In principle, the pipeline can then be drawn to the destination point or starting point, depending on which side it has been prepared for. Preferably, as already mentioned above, however, pressure forces (in the axial direction) are also exerted on the pipeline for moving the pipeline through the borehole, so that the pipeline as a whole can be more easily introduced into the borehole than if it were only advanced. For pulling on the support pipe string, in principle, the above-mentioned pusher can be used, which transmits its forces on the lateral surface of the pipe string, the device operates when used as a pulling device in the opposite direction and engages the opposite end of the borehole, as compared to the application advancing.

The drill head is preferably decoupled after reaching the target point. The support tubing may be sectioned at the target point (or, if it is moved back to the starting point, at the start point), e.g. in individual support tubes. But it is also conceivable to lead out the support tube strand over a greater length of the borehole and separate later.

A particular advantage of the method according to the invention in comparison to that of DE 10 2006 020 339 A1 Prior art method (which uses no support tubes) is that can be installed between two adjacent support tubes a Dehnerstation (intermediate press station). If required, a larger number of extension stations can be distributed over the support pipe string. Dehnerstationen are known from the procedures in microtunneling. When the propulsive forces during advancement of the Support pipe string along the laying line exceed the possibilities of the pressing device or the strength of the support tubes, you can use Dehnerstationen, each applying the necessary pre-pressing until the next Dehnerstation. In principle, Dehnnerstationen can be used, which apply only compressive forces, but tensile strength connections can also be used Dehnerstationen with pressure and traction. When the wellbore is completed to completion with the help of the support tubing, the tubing can be moved with the facilities at the start point or target point in the wellbore without requiring comparable dilator stations on the tubing.

If many Dehnerstationen be used, in principle, an arbitrarily long tunneling distance between starting point and destination point is possible.

Furthermore, it is advantageous if a lubricant is introduced on the outside of the support pipe string (for example concrete), preferably via lubricating nipples provided on at least individual support pipes. This allows for continuous lubrication during propulsion of the support pipe string and thus greatly facilitates the completion of the wellbore.

Compared to that from the DE 10 2006 020 339 A1 Although known methods must first be introduced in the inventive method, a support pipe string. On the other hand, this allows significantly longer distances between the starting point and the destination point, since the borehole is supported by the support tubes and the use of Dehnerstationen and a continuous lubrication are possible.

At the starting point, an excavation is preferably provided (eg, a shallow pit), which involves feeding longer lengths of a prepared pipeline or a prepared support pipe string facilitated. The area of the destination point can be in a pit or in a shaft, for example. As a destination is but also a valley or a low point on the slope of a mountain suitable. Here are some examples given below.

Furthermore, there is basically the possibility of arranging between the starting point and the target point at least one intermediate shaft in which a device is arranged with the tensile and / or compressive forces can be exerted on the support pipe string or the pipe to the advancement of the support pipe string or pipeline to the destination point.

That from the DE 10 2005 021 216 A1 A known method can be modified by preparing the pipeline not on the side of the target point but on the side of the starting point and pulling it into the borehole with a pulling device at the target point. More specifically, this is a trenchless piping method in which a controlled pipe advance is guided under an obstacle to a target point from a starting point, a drill head being advanced from the starting point with support tubes toward the target point and the borehole generated thereby already widened to its final diameter and supported by the support tubes and the soil dissolved by the drill head is conveyed out of the wellbore and wherein the support pipe string formed from the support tubes is tensile strength. A pipeline prepared at least in partial sections on the side of the starting point is then coupled to the support pipe string after the boring head has reached the target point, and tensile forces are applied to the support pipe string from the target point to draw the pipe coupled to the support pipe string into the borehole. On the revelation in DE 10 2005 021 216 A1 is expressly incorporated by reference.

Figur 1

schematische Darstellungen von prinzipiellen Einsatzmöglichkeiten des erfindungsgemäßen Verfahrens, und zwar in Teil (a) eine Bohrlinie von einer Baugrube als Startpunkt unter einem Hindernis zu einer Baugrube als Ziel, in Teil (b) eine Bohrlinie von einer Baugrube als Startpunkt unter einem Hindernis zu einem Schacht als Zielpunkt und in Teil (c) eine Bohrlinie von einer Baugrube als Startpunkt unter einem Hindernis zu einer Talsohle oder einem Gewässergrund als Ziel,

Figur 2

schematische Darstellungen aufeinanderfolgender Verfahrensschritte bei einem ersten Ausführungsbeispiel für das erfindungsgemäße Verfahren, bei dem eine Bohrlinie von einer Baugrube unter einem Hindernis zu einer Baugrube verläuft, und zwar in Teil (a) die Startsituation, in Teil (b) das Erstellen des Bohrlochs und Einschieben des Stützrohrstrangs zur Stützung des Bohrlochs, in Teil (c) die Vorbereitungen für das Einschieben der vorbereiteten Rohrleitung, in Teil (d) das Einschieben der Rohrleitung und das Ausschieben des Stützrohrstrangs und in Teil (e) die eingeschobene Rohrleitung nach Fertigstellung,

Figur 3

schematische Darstellungen aufeinanderfolgender Verfahrensschritte bei einem zweiten Ausführungsbeispiel für das erfindungsgemäße Verfahren, bei dem eine Bohrlinie von einer Baugrube unter einem Hindernis zu einem Zielschacht verläuft, und zwar in Teil (a) die Startsituation, in Teil (b) das Erstellen des Bohrlochs und Einschieben des Stützrohrstrangs zur Stützung des Bohrlochs, in Teil (c) die Vorbereitungen für das Einschieben der vorbereiteten Rohrleitung, in Teil (d) das Ein-

schieben der Rohrleitung und das Ausschieben des Stützrohrstrangs und in Teil (e) die eingeschobene Rohrleitung nach Fertigstellung,

Figur 4

schematische Darstellungen aufeinanderfolgender Verfahrensschritte bei einem dritten Ausführungsbeispiel für das erfindungsgemäße Verfahren, bei dem eine Bohrlinie von einer Baugrube unter einem Hindernis zu einer Talsohle verläuft, und zwar in Teil (a) die Startsituation, in Teil (b) das Erstellen des Bohrlochs und Einschieben des Stützrohrstrangs zur Stützung des Bohrlochs, in Teil (c) die Vorbereitungen für das Einschieben der vorbereiteten Rohrleitung, in Teil (d) das Einschieben der Rohrleitung und das Ausschieben des Stützrohrstrangs und in Teil (e) die eingeschobene Rohrleitung nach Fertigstellung,

Figur 5

eine Variante des ersten Ausführungsbeispiels, schematisch dargestellt anhand des Verfahrensschritts entsprechend Figur 2d,

Figur 6

eine schematische Darstellung der wesentlichen maschinentechnischen Komponenten zum Erstellen des Bohrlochs vor dem Einführen des Bohrkopfs und der Stützrohre und

Figur 7

eine schematische Darstellung der wesentlichen maschinentechnischen Komponenten zum Einschieben der vorbereiteten Rohrleitung nach dem Erstellen und mechanischen Stützen des Bohrlochs.

In the following the invention will be further explained by means of exemplary embodiments. The drawings show in

FIG. 1

schematic representations of basic applications of the method according to the invention, in part (a) a drilling line from an excavation as a starting point under an obstacle to an excavation target, in part (b) a drilling line from a pit as a starting point under an obstacle to a shaft as a target point and in part (c) a drill line from an excavation pit as a starting point under an obstacle to a bottom of the valley or a body of water as the target,

FIG. 2

schematic representations of successive process steps in a first embodiment of the inventive method in which a drilling line from an excavation under an obstacle to an excavation runs, in part (a) the starting situation, in part (b) creating the borehole and inserting the Supporting pipe string to support the borehole, in part (c) the preparations for the insertion of the prepared pipeline, in part (d) the insertion of the pipeline and the pushing out of the support pipe string and in part (e) the inserted pipeline after completion,

FIG. 3

schematic representations of successive process steps in a second embodiment of the inventive method in which a drilling line from an excavation under an obstacle to a target shaft runs, in part (a) the starting situation, in part (b) creating the borehole and inserting the Supporting pipe string to support the borehole, in part (c) the preparations for the insertion of the prepared pipeline, in part (d)

pushing the pipeline and pushing out the support pipe string and in part (e) the inserted pipe after completion,

FIG. 4

schematic representations of successive process steps in a third embodiment of the inventive method in which a drilling line from an excavation under an obstacle to a bottom, in part (a) the starting situation, in part (b) the creation of the borehole and insertion of the Supporting pipe string to support the borehole, in part (c) the preparations for the insertion of the prepared pipeline, in part (d) the insertion of the pipeline and the pushing out of the support pipe string and in part (e) the inserted pipeline after completion,

FIG. 5

a variant of the first embodiment, shown schematically by the method step accordingly Figure 2d .

FIG. 6

a schematic representation of the essential mechanical components for creating the borehole prior to insertion of the drill head and the support tubes and

FIG. 7

a schematic representation of the essential mechanical components for insertion of the prepared pipeline after creating and mechanical supports of the borehole.

In FIG. 1 are given in a schematic manner by way of examples fundamental possibilities for the course of a pipeline, which is laid by the method according to the invention.

In the first example ( FIG. 1a ), the method is carried out from a starting point 1 in a pit (starting pit) 2 under an obstacle 9 in a predetermined drilling line 7 to a target point 3 in a near-target target pit 4.

In the second example of the method, the drilling line 7 runs from a starting point 1 in a starting pit 2 under an obstacle 9 to a target point 3 located in a low-lying target pit 4 (ie a shaft), see FIG. 1b ,

In the third example, the method is carried out from a starting point 1 in a starting excavation 2 in a predetermined drilling line 7 to a destination point 3, which lies freely in the area without a prepared excavation pit, eg in a body of water 10 (as in FIG Figure 1c ) or in a valley or at the foot of a slope.

The following is based on the FIG. 2 described in more detail how the method is carried out according to the first example.

As in FIG. 2a 1, the starting point 1 is located in a relatively shallow starting pit 2 and the target point 3 is in a target pit 4. First, support tubes 11 (which may in principle have different lengths) are coupled together to form a pipe string 8 (support pipe string) on the terrain in front of the starting pit 2 , Before the starting excavation 2, but also in the starting excavation 2, a pusher 5 is installed and anchored with an abutment 20. Furthermore, a drilling device is prepared in the starting excavation pit 2, which is essentially a conventional microtunnelling drilling unit with a boring head 6. The support pipe string 8 is firmly connected to the drill head 6.

Now, with the aid of the boring device 6, a boring is carried out along a predetermined boring line 7 which runs underneath an obstacle 9, as in FIG FIG. 2b shown. In this case, the drill head 6 is pressed by the pusher 5 via the support pipe string 8 against the soil material, as is required for the drilling operation. According to the known techniques of controlled pipe jacking, the positions of the drill head 6 are measured and its movement is controlled along the predetermined drilling line 7.

The drilling process along the drilling line 7 is continued until the drill head 6 has reached the target point 3 in the target pit 4, see Figure 2c , The support pipe string 8 now supports the borehole 12 in its full length. The drill head 6 is dismantled and removed.

Now a prepared on the start pipe 14 (product tubing) is moved into the drill pipe. In the region of the starting point 1, the pipe 14 is connected to the support pipe string 8 by means of a connecting element 13.

As in Figure 2d shown, the pipe 14 is then pushed by means of the pusher 5 in the prepared hole 12, at the same time the support pipe string 8 is advanced into the target pit 4. On the target side, ie at the destination point 3 or in its near or even further surroundings, the individual elements of the support pipe string 8, ie the support pipes 11, are dismantled.

After the pipe 14 has been completely inserted from the starting pit 2 to the target pit 4, and the connecting element 13 can be dismantled. If necessary, the pipeline 14 is shortened in the area of the starting excavation 2 or the target excavation 4. The FIG. 2e shows the final state.

In a variant of this embodiment, the pipeline is prepared not on the side of the starting point 1 but on the side of the target point 3. First, the support pipe string 8 is advanced until in the Figure 2c shown state is reached. Then the drill head 6 is removed. Subsequently, a connector is mounted at the location of the drill head 6, via which the assembled on the side of the target point 3 pipe is connected to the support pipe string 8. Now can be with a anchored in the vicinity of the target pit 4 pusher (similar to the pusher 5 at the starting point 1 or the same so) advance the pipe to the starting point 1, wherein the support pipe string 8 emerges from the borehole 12 at the starting point 1 and can be disassembled there ,

If the support tubing string 8 is tensile, the tubing 14 may be advanced into the wellbore 12 from one end of the wellbore 12, as in the embodiment, and at the same time from the other end of the wellbore 12 via the support tubing string 8 into the wellbore 12, as described above explains what the process of introducing the pipe 14 into the borehole 12 can facilitate. This is in the too Figure 2d analog FIG. 5 illustrates where at the starting point 1 and at the destination point 3 substantially identical devices 5 are used with abutment 20 for advancing or retracting.

Based on FIG. 3 Now the second example is clarified. For same parts, the same reference numerals are used as before.

The starting point 1 is located in a starting pit 2, while the target point 3 is formed in a relatively deep target shaft 16. First, 2 support tubes 11 are coupled together to form a support pipe string 8 on the site in front of the starting excavation pit. Before the starting excavation 2, but also in the starting excavation 2, a pusher 5 is installed and anchored with an abutment 20. In the starting excavation 2, a drilling device with a drill head 6 is prepared. This is essentially a conventional microtunnelling drilling unit, as in the first example. The support pipe string 8 is connected to the drill head 6. These steps are in FIG. 3a shown.

As FIG. 3b now shows the drill head 6 along the drilling line 7, which runs under an obstacle 9 (here a river), a borehole 12, wherein the wall of which is supported by the support pipe string 8. The required pressure forces for the drill head 6 are transmitted from the pusher 5 via the support pipe string 8. As before, the drill bit 6 is measured in position according to prior art controlled pipe jacking techniques and controlled in its movement along the pre-planned drilling line 7.

The drilling process along the drilling line 7 is continued until the drill head 6 has reached the target point 3 in the target shaft 16, see Figure 3c , There, the drill head 6 is dismantled and removed, see 3d figure ,

The Figures 3c and 3d also show how a prepared on the home pipe 14 is advanced into the drill pipe and connected by means of a connecting element 13 with the support pipe string 8. Now, the pipe 14 is pushed with the pusher 5 in the prepared hole 12, at the same time the support pipe string 8 is advanced into the target shaft 16. There are the individual elements, the support tubes 11, dismantled, see Figure 3d and Figure 3e ,

After the pipe 14 is completely inserted from the starting pit 2 to the target shaft 16, the connecting element 13 is dismantled. If necessary, the pipeline 14 is shortened in the region of the starting excavation 2 and / or the aiming shaft 16, see FIG. 3e ,

The third example is based on the FIG. 4 illustrated.

This time, the starting point 1 is in a starting pit 2 and the target point 3 in a bottom 10, whereby the target point 3 is open, see FIG. 4a ,

First, 2 support tubes 11 are coupled together to form a support pipe string 8 on the grounds of the starting excavation pit. Before the starting excavation 2, but also in the starting excavation 2, a pusher 5 is installed and anchored with an abutment 20. Furthermore, a drilling device with a drill head 6 is prepared in the starting excavation 2. As before, this is essentially a conventional microtunnelling drilling unit. The support pipe string 8 is firmly connected in the starting excavation 2 with the drill head 6, see FIG. 4a ,

With the help of the drilling device 6 is now carried out along the predetermined drilling line 7 a hole, wherein the drilling device 6 is pushed by the pusher 5 via the support pipe string 8. The measurement of the position of the drilling apparatus 6 and the control along the drilling line 7 are carried out according to the techniques of controlled pipe jacking, see FIG. 4b ,

The drilling process along the drilling line 7 is continued until the drilling device 6 has reached the target point 3 in the bottom 10, see Figure 4c ,

A prepared on the home pipe 14 is now moved into the drill pipe and connected by means of a connecting element 13 with the support pipe string 8, see Figure 4c ,

With the help of the pusher 5, the pipe 14 is pushed into the prepared hole 12, at the same time the drill head 6 and the support pipe string 8 are advanced through the hole 12.

On the target side of the drill head 6 and the support pipe string 8 and its individual elements (support tubes 11) are dismantled, see FIG. 4d ,

If the pipe 14 is completely inserted from the starting shaft 2 to the destination point 3, it is possibly shortened in the area of the starting excavation pit 2 and the destination point 3, see Figure 4e ,

In a variant of the third example, the pipeline is prepared before the target point 3 (as in the variants of the first example). The second example is less suitable for such a variant, since in the target shaft 16 no longer pipeline can be put together.

In the FIGS. 6 and 7 the essential mechanical components for carrying out the method are shown in an enlarged view.

First, in a starting pit 2, the boring head 6 (boring device) is connected to the supporting pipe string 8 via a connecting member 13 (in which conventional intermediate pressing or stretching stations 15 are installed at one or more locations). In this case, the drill head 6 is located on a guide frame 22. The drill head 6 has a cutting wheel 27 as a cutting tool on, which is provided in the embodiment with high-pressure nozzles. The free end portion of the prefabricated support pipe string 8 is mounted on roller blocks 21. Near the starting pit 2 is the pusher 5, which introduces the forces required for the propulsion in the support pipe string 8 (via its lateral surface) and is thereby supported via an abutment 20 on the ground.

The drilling device 6 is supplied and energized via power and control cable 18. Fresh drilling mud is conducted by means of a feed line 17 to the cutting wheel of the drilling device 6, while the drill cuttings loaded with cuttings are transported out of the borehole via a feed line 19. The said control and supply lines or cables run within the support pipe string 8 and are removed after reaching the target point 2 from the support pipe string 8.

The power and control cables 18 lead to a control station 23, which simultaneously ensures the power supply. The feed line 17 connects the drill head 6 to a drilling fluid mixing unit 24, which is provided with a pump, and supplies the drilling head 6 with fresh drilling fluid. The delivery line 19 leads to a drilling fluid treatment plant 26, in which the drilling fluid is cleaned from the cuttings. Thereafter, the drilling mud can in turn be supplied via a connecting line 25 of the drilling fluid mixing plant 24, so that a cycle is created. The drilling fluid serves as a lubricant and can be dispensed, if necessary, also on numerous support tubes in the annular space between the borehole 12 and the support tube 8 in order to ensure a smooth feed. The drill cuttings containing the cuttings are collected and fed to the delivery line 19.

In FIG. 7 FIG. 3 illustrates how the rearmost support tube 11 of the support pipe string 8 is connected to the prepared pipe string 14 by means of a connection element 13 (which may be constructed differently from the aforementioned connection element 13). In the exemplary embodiment, the pusher 5 derives FIG. 6 Also, the required propulsive forces in the tubing string 14, so that the tubing string 14 is inserted into the borehole 12 and the support tubing 8 at the target point 3 emerges from the borehole 12.

The representation in the FIGS. 6 and 7 is not to scale. With low elasticity of the support pipe string 8 or of the pipe string 14, large radii of curvature are recommended. If necessary, articulated pipe connections can also be installed at pre-selected intervals.

LIST OF REFERENCE NUMBERS

1

starting point

2

starting excavation

3

Endpoint

4

target pit

5

pusher

6

Drill head (drilling device)

7

drilling line

8th

Support tube train

9

obstacle

10

Bottom of the valley (water bottom)

11

support tube

12

well

13

connecting element

14

Pipeline (product pipeline)

15

Intermediate press station (Dehnerstation)

16

target shaft

17

feeder

18

Power and control cables

19

delivery line

20

abutment

21

rollerstands

22

guide frame

23

Control station with power supply

24

Drilling fluid mixing plant with pump

25

connecting line

26

Drilling fluid treatment plant

27

cutting wheel

Claims (17)

Method for the trenchless laying of pipelines, in which a controlled pipe advance under an obstacle (9) is guided from a starting point (1) to a destination point (3), - With a drill head (6) starting from the starting point (1) with support tubes (11) in the direction of the target point (3) is advanced and the borehole (12) produced already expanded to its final diameter and supported by the support tubes (11) and the soil released from the drill head (6) is conveyed out of the wellbore (12), wherein a pipeline (14) prepared at least in sections is coupled to the support pipe string (8) formed by the support pipes (11) and moved through the borehole (12), the support pipes (11) emerging from the borehole again, - Characterized in that the pipe (14) is advanced under the exertion of compressive forces through the borehole (12). A method according to claim 1, characterized in that the pipe (14) after coupling to the support pipe string (8) pushes the support pipe string (8) through the borehole (12). A method according to claim 2, characterized in that the propulsion force for advancing the pipe (14) with a pusher device (5, 20) over the lateral surface of the pipe (14) is applied. Method according to one of Claims 1 to 3, characterized in that the pipeline (14) is moved from the side of the starting point (1) into the borehole (12). A method according to claim 4, characterized in that the pipe (14) is coupled to the support pipe string (8) after the drill head (6) has reached the target point (3). A method according to claim 4, characterized in that the pipe (14) is coupled to the support pipe string (8) before the drill head (6) has reached the target point (3). Method according to one of claims 1 to 3, characterized in that the pipeline (14) is moved from the side of the target point (3) into the borehole (12) and is coupled to the support pipe string (8) after the boring head (6 ) has reached the destination point (3). Method according to one of claims 1 to 7, characterized in that the support pipe string (8) is adapted for transmitting tensile forces and that after coupling the pipe (14) to the support pipe string (8) at the opposite end of the borehole (12) tensile forces the support pipe string (8) are exerted so that the pipeline (14) both in the borehole (12) advanced as well as in the borehole (12) is pulled. Method according to one of claims 1 to 8, characterized in that the drill head (6) is uncoupled after reaching the target point (3). Method according to one of claims 1 to 9, characterized in that the soil from the drill head (6) dissolved soil is hydraulically conveyed from the borehole (12). Method according to one of claims 1 to 10, characterized in that between two adjacent support tubes (11) a Dehnerstation (15) is installed. Method according to one of claims 1 to 11, characterized in that on the outside of the support pipe string (8) a lubricant is brought, preferably via on at least individual support tubes (11) provided for grease nipple. Method according to one of claims 1 to 12, characterized in that at the starting point (1) an excavation (2) is provided. Method according to one of claims 1 to 13, characterized in that at the target point (3) an excavation (4) is provided. Method according to one of claims 1 to 13, characterized in that at the target point (3) a shaft (16) is provided. Method according to one of claims 1 to 15, characterized in that between the starting point (1) and the target point (3) at least one intermediate shaft is arranged, in which a device is arranged, which is adapted to tensile and / or compressive forces to exert the support pipe string (8) or the pipe (14) to facilitate the advancement of the support pipe string (8) and the pipe (14). Method for the trenchless laying of pipelines, in which a controlled pipe advance under an obstacle (9) is guided from a starting point (1) to a destination point (3), - With a drill head (6) starting from the starting point (1) with support tubes (11) in the direction of the target point (3) is advanced and the borehole (12) produced already expanded to its final diameter and supported by the support tubes (11) and the soil released from the drill head (6) is conveyed out of the wellbore (12) and - wherein the support pipe string (8) formed from the support tubes (11) is tensile strength, - characterized in that on the side of the starting point (1) at least in sections prepared pipeline (14) is coupled to the support pipe string (8) after the drill head (6) has reached the target point (3), and that from the target point ( 3) from tensile forces on the support pipe string (8) are exerted to feed the pipe (14) coupled to the support pipe string (8) into the borehole (12).

Images