DE102006052261A1 - Method for laying a pipeline - Google Patents

Abstract

In a method of laying a pipeline composed of a plurality of separate pipe sections (6) at a subterranean level (17) along a pipeline line (4), comprising the steps of: excavating a trench (18); Making the pipe on site by welding the pipe sections (6) together; Introducing the pipeline into the trench (18); Filling the trench; To minimize excavation and surface use, it is proposed that the welding be stationary and the tubing string be introduced into the trench (18) from the stationary welding station.

Description

• – Ausheben eines Grabens;
• – Herstellen der Rohrleitung vor Ort durch Verschweißen der Rohrabschnitte miteinander;
• – Einbringen der Rohrleitung in den Graben;
• – Verfüllen des Grabens.

The present invention relates to a method for laying a pipeline composed of a plurality of separate pipe sections at a subterranean level along a pipeline route, comprising the steps:

• - digging a trench;
• - Making the pipe on site by welding the pipe sections together;
• - introducing the pipeline into the trench;
• - filling the trench.

such Procedures are used, for example, to lay pipelines over land. Usually will be for this purpose first Along the entire course of the pipeline route a working strip cleared from about 20 to 22 m wide. Subsequently, will in the working strip the topsoil cleared to the side. In the working strip then the individual pipe sections of designed to be laid pipeline. In addition, in the area of Workstrip set up one or more mobile welding stations, in where the pipe sections are welded together to complete the pipe to produce locally. This welding process takes place within of the working strip on the surface. To do this, the welding station moved along the pipeline route according to the construction progress, so that the pipe sections are welded at the intended installation location can. Subsequently is in the conventional Procedure along the planned pipeline route within the Working strip of soil excavation made down to the desired level of conduction down. After completion of the trench along the entire length of the welded Pipeline string is the tubing string in the excavated Ditch lifted. Afterwards the soil filling is done, the topsoil reapplied and a reclamation made.

at this known method of the generic type is disadvantageous the Landscape for a period of typically three to four months sensitive disturbed, because along the entire pipeline line a working strip with the width mentioned must be disclosed. This can cause that Farmers are interrupted in their production when the pipeline route over agricultural production areas runs. Does the Pipeline route over natural Area, so by the known method the ecology disturbed, what increasingly resistance from the population or even to legal prohibitions. Another disadvantage of known method is that a mobile welding station constantly along the pipeline line with the construction progress must be moved to each to weld the tubing string where it then dug into the Ditch should be lowered. A transport one at a central Welded place Pipe line is generally out of the question, as this would be too expensive and In addition, the risk of damage the welds harbors.

The The present invention therefore has the object, the method to laying piping of the type mentioned in the way to improve that environment and agriculture through the piping as little as possible disturbed while still producing pipelines over several kilometers and can be relocated.

These The object is achieved according to the invention by in a method of the type mentioned, the welding takes place stationary and the tubing string from the stationary welding station into the trench is introduced.

If the stationary one weld together carried out above ground is, it is particularly advantageous according to the invention, when the Pipe string over a section is inserted inclined. A completed pipe section will then over an inclined plane to the final one Cable level pushed, pulled or pressed.

alternative can in an embodiment of the method according to the invention the pipe string is introduced from an excavation in the trench. These process steps is particularly advantageous if the welding takes place in a pit.

In preferred embodiment of the method according to the invention, the pipe string is through Thrust advanced by means of a pusher. For example The pusher can work together with a welding station be arranged in a pit. The required for propulsion Force on the pipe string is then applied from this excavation, without the need for additional devices along the route.

According to one another advantageous embodiment the method according to the invention the pipe string is introduced by train in the trench, in particular by pulling by means of at least one in a propulsion pit arranged driven traction device. The pulling device can typically at the tube tip of the tubing string, which should be driven, be recognized. As particularly suitable Pulling devices have proven to be ropes, chains and or tie rods.

to Facilitation of the propulsion is in an embodiment of the method according to the invention led the tubing during insertion, in particular, the Pipeline guided or driven by drivable transport rollers. The Transport rollers can especially at the bottom of the pipe, ie at the bottom of the trench be. As drive for The transport rollers are suitable for electrical or hydraulic drives.

A other embodiment the method according to the invention provides that the tubing is lubricated during insertion. By this measure the frictional resistance of the pipe string is reduced during propulsion. For lubrication can all known lubricants are used, which are the material, from which the tubing string consists, do not attack. For example, can Silt or clay dispersion can be used. Such lubricants are ecological and for the agriculture harmless.

alternative let yourself according to the invention, the frictional resistance during propulsion also reduce by the pipe string is weight relieved during insertion. For this purpose can the pipe string can be hung for example on a portal.

Around with the method according to the invention also particularly long pipelines, e.g. over several kilometers, embarrassed to be able to is proposed in a further advantageous embodiment that the pipe string is driven when introduced at several points. This measure is particularly useful whenever the friction of the pipe string is particularly large due to the soil condition.

In preferred embodiment the invention, the reaction forces are intercepted stationary during insertion. Mobile units can thus be dispensed with.

To overload along the pipe string, causing damage in the area of the welds between lead the pipe sections could To avoid, is carried out in a specific embodiment of the invention a Synchronization of the drives during insertion of the pipe string.

In other cheaper Embodiment of the invention is the tubing during insertion sealed at least at one point for digging. For example can the pipe opening be closed with a plastic lid to avoid that is contaminated during insertion of the interior of the pipeline.

According to one especially favorable execution The invention relates to the following method steps: the Excavation pit is excavated as a starting pit, whose expansion in Direction of the pipeline route substantially the length of a separate pipe section plus one for implementation welding required working length obtained; along the pipeline route is in addition to the starting excavation pit at least one of these separate propulsion pit excavated, which of the starting pit as well as, if several propulsion ditches be excavated, to adjacent propulsion ditches at a distance is arranged; each between two construction pits is along the Pipeline road by Rohraushub a trench with a pipe bottom excavated; the pipeline will be successively divided into sections of separate Lowered pipe sections in the starting pit; every pipe section is added to the previously lowered pipe section in the starting pit welded to a pipe string and then in pushed on the ditch.

The main advantage of this variant of the method according to the invention over the conventional method is that compared to the conventional method, only a minimal excavation of the soil and only minimal use of the surface is required. In the simplest case, in addition to the trench, only a starting excavation pit and a driving excavation pit are needed. In addition, it is possible according to the inventive method to perform the welding for the entire pipeline exclusively within the starting excavation. In the case of small nominal widths of the pipe with a small wall thickness or generally with the use of modern laser welding methods, the welding process can be carried out in a single welding station. Carrying a welding station following the progress of pipeline construction, as in the conventional method, thus eliminates with great advantage. Rather, according to the invention, a single welding station can be installed in the appropriately dimensioned starting excavation at the line level. For example, a modern compact welding station, in particular laser welding station, can be used in the launch pit. For the creation of the trench between the individual excavations, all known methods can be used. With the help of the Vortriebsbaugruben, which are excavated according to the invention along the pipeline route to expand the trench, the pipe jacking can be supported. The distance of a propulsion pit to the starting excavation pit or to the adjacent further excavation excavation should be suitably chosen depending on the ground route, the pipe diameter, the weight of the pipes and similar parameters to ensure that the pipe jacking with the selected Rohrvortriebsmitteln is easily feasible. For particularly hard ground, with particularly large pipe penetration Knives and in the case of particularly large dead weight of the pipes will make sense to choose a smaller distance between the driving excavation with each other or between a Vortriebsbaugrube and the starting pit, as in light soils, small pipe diameters and low weight of the tubes. It is always crucial that sufficient jacking forces are available to move the pipe string easily. In the context of the invention, it is possible to lay both straight pipe routes as well as with a certain bending radius provided pipes. For propulsion of the tubes all known Rohrvortriebsverfahren and devices can be used.

The weld together the pipe sections to the tubing designed in design the method according to the invention especially cheap if the pipe sections by orbital welding or by a laser welding process, preferably using an orbital welding device with a high power fiber laser beam source and a laser welding head, and / or with a MAG welding process be welded together. When orbital welding become devices for welding used by tubes along the tube circumference. Orbital welding can be used mobile. There are welding systems for orbital welding, which mobile generators, mobile heat exchangers and transportable fluid and gas tanks to get off the infrastructure independent on site to be. Come as orbital welding in the context of the method according to the invention manual, partially or fully mechanized procedures or combinations in question. Decisive for the usability in connection with the method according to the invention is that the welding process stationary in the starting pit or above ground.

For laser welding, for example, an orbital welding apparatus according to the disclosure can be used within the scope of the invention WO 2005/056230 A1 be used. With regard to the details of this Orbitalschweißvorrichtung reference is made to the disclosure of said document. Thus, it is possible according to the document, tubes which consist of a melt-weldable material, in particular steel material or high alloyed, stainless steel and have a diameter of 50 mm to more than 4,000 mm with a wall thickness of 2.5 mm to over 25 mm, within a short time to connect with an orbital circulation. The suitability of laser welding methods, and in particular of said orbital welding apparatus for mobile and self-sufficient use, also makes this method or apparatus suitable for producing pipelines to be laid horizontally on land in an environment in which there is only a poor or no infrastructure in the form of a solid power, Water or gas supply is available, applicable. A particular advantage of laser welding method in connection with the method according to the invention is that by means of only a single welding operation within a short time the joining of two pipe ends in field use in autonomous operation is possible.

in the Trap of MAG welding process is advantageous that these are widespread, so that in the Operating personnel a considerable Experience in the application is available. When using of MAG welding process for the orbital welding becomes common in one operation only the root welded, whereas the cover layers as well the filling levels or the hotpass manually welded become. Especially in low-wage countries is the use of MAG welding process due to the lower initial cost of a MAG welding machine compared to, for example, a laser welding device advantage. requirement for the Applicability of MAG welding to carry out the method according to the invention is always that the welding feasible in the starting pit is.

to Avoidance of inadequate welded joints between the pipe sections is according to a preferred embodiment of the Invention provided that a quality control of the weld, preferably by means of ultrasound or X-ray diagnosis, carried out becomes. These quality control procedures can be inventively problem-free in the interior of the starting pit at, for example, one installed there for welding welding station carry out. It is thus advantageously avoided that a faulty weld is driven into the trench between two pipe sections of the pipe string. Instead, in case of detected quality defects, the welded joint immediately afterwards on site in the starting pit with help of the chosen welding process be improved.

to Improvement of the resistance the welded joints between the pipe sections provides a further preferred embodiment of the inventive method before that the welded joints be provided with a corrosion protection. Depending on the soil condition, the Weather conditions and in the finished pipeline to be transported medium come within the scope of the invention for the production of corrosion protection a bitumen cladding, a sintering, a Cement cladding and / or a lamination of the welded joint in Question.

In a further advantageous embodiment of the method according to the invention, the tubing string pushed by thrust by means of a pusher. The thrust can be suitably transmitted in the starting pit and / or in one or more of the propulsion ditches on the pipe string.

Especially takes place in a preferred embodiment the method according to the invention the thrust for the introduction of the pipe string by means of a pusher in the starting pit. This is a propulsion of each newly introduced into the starting pit pipe section immediately after welding on the existing pipe string possible. Especially in comparison to other positions of a pusher and also in comparison to alternatively conceivable pulling devices this has the advantage that no communication about the Progress of welding work with the propulsion devices is required because the welding station and the pusher in close proximity to each other within the same Starting excavation are located.

If in a further improvement of the method according to the invention, the pusher is arranged in one or more propulsion ditches, can by the interaction of several thrusters along the pipeline route applied higher shear forces become. This allows also longer and / or heavier and / or larger tubing strings e.g. also in trenches with a particularly big one Friction be driven.

In special development of the method according to the invention is the pipe string with baking on a peripheral surface encompassed the pipe string and, preferably hydraulically, pushed. On the market are so-called "pipepushers" to carry out this Procedural step available. Such "pipepushers" are used if in the production of water crossings by means of HDD - (Horizontal Directional drilling) in the final operation the prefabricated pipeline is pulled into the borehole. There at huge lengths the tensile forces the HDD unit not sufficient, there are additionally used "pipepushers" which Push the pipe string with hydraulic cylinders into the drilled hole. In these methods, the tensile force of the HDD rig adds to the thrust of the "pipepusher" to a total propulsive force.

in the Framework of the method according to the invention can the "pipepushers" both alone and also in combination with several Pipepushern in several propulsion ditches as well as in connection with traction devices are used.

In another embodiment the method according to the invention the trench is flooded. Also by this measure, both a reduction in friction achieved in the propulsion of the pipe string as well as a reduction the risk of damage the pipe string and in particular the welded joints. The flood of the Pipe sole is particularly suitable when the line level in nearby the groundwater level is.

The Invention is in a preferred embodiment with reference on a drawing by way of example, with further advantageous details the figures of the drawing can be seen.

Functionally same Parts are provided with the same reference numerals.

The Figures of the drawing show in detail:

1 a schematic plan view of a construction site for laying a subterranean pipeline, in which the inventive method is used with a welding station in a pit;

2 a sectional side view of a construction site, in which according to an alternative embodiment of the method according to the invention, a welding station is arranged above ground;

3 a vertical section along the line III-III in the 1 ;

The 1 schematically shows a plan view of a construction site for a pipeline to be laid over land 1 , where the pipeline 1 is laid according to the method of the invention.

Right in the 1 is a starting pit 3 to recognize. The starting excavation pit 3 has in the direction of the pipeline road 4 a longitudinal extent 5 , The longitudinal extent 5 the starting pit 3 consists of a working length, corresponding to the length of the laser orbital welding station, and a length of the pipe sections 6 so that these in horizontal orientation in the starting pit 3 fit in with the already in the trench 18 propelled tubing by means of the in the starting pit 3 housed welding station 7 to be welded.

Inside the starting pit 3 there is a pipe section 6 , It is also located in the starting excavation pit 3 a schematically indicated by a rectangle laser orbital welding station 7 , Moreover, inside the starting pit 3 a pipe pusher 8th accommodated. The pipe pusher 8th , which is also shown only schematically, has a few jaws 9 for making a pressure connection with the pipe sections 6 on. The cheeks 9 are over a linkage 10 with an abutment 11 connected. The abutments 11 are in the soil of the starting pit 3 supported in the usual way.

At a distance 12 from the starting pit 3 are along the pipeline route 4 two propulsion ditches 13 to recognize. In every jacking pit 13 is each a Rohrpusher 8th Installed. The pipe pushers 8th correspond in terms of construction to the pipe pusher 8th in the starting pit 3 , However, the pipe pushers are 8th in the two propulsion ditches 13 on the back walls 14 of the soil of the propulsion ditches 13 with the abutments 11 supported.

Along the pipeline road 4 is a pipe trench 18 dug, which also by the Vortriebsbaugruben 13 and the starting pit 3 runs.

The pipe sections 6 are each at welds 16 welded together.

The pipe trench 18 is with annular seals 21 against the starting pit 3 and the propulsion ditches 13 sealed. The seals 21 surround the pipeline 1 annular.

In the trench 8th are lateral guide rollers 22 whose axis is vertically oriented, present the pipeline 1 When driving forward and prevent the pipeline along the side walls of the trench 8th rubs. The guide rollers can be arranged along the entire length of the trench. In the figure, only one pair is drawn. Further, in the tubular sole 17 at the bottom of the trench 18 , Support rollers 23 present, whose axis is aligned horizontally. The support rollers 23 serve the pipeline 1 to prop up during propulsion. Support rollers can be at different places on the ground 17 of the trench 18 be used. In the figure, for reasons of clarity, by way of example only a single supporting role 23 located. The end of the pipeline 1 is with a plastic lid 24 sealed.

2 shows another site in a vertical sectional view, in which an alternative embodiment of the method according to the invention is used to a pipeline 1 relocate. In addition to the in 1 shown and described above features can be seen in 2 the tube sole 17 , The tube sole 17 corresponds to the bottom of the trench 18 , Next is in 2 to realize that the laser orbital welding station 7 not as in the case of 1 in the starting pit 3 is erected, but above ground in a preparation area 20 on the terrain surface 2 , The preparation area 20 is located in the 2 right from the beginning of the trench 18 , Between the preparation area 20 and the beginning of the trench 18 there is an inclined plane 25 with one of those of the trench 18 corresponding width. The inclined plane 25 connects the terrain surface 2 with the tube sole 17 So, with the bottom of the trench 18 , In the in 2 shown situation is a pipe section 6 in the area of the inclined plane 25 , In 2 is the terrain surface 2 in the area of the preparation area at a different level than in the area of the trench 18 , However, this is irrelevant to the invention. The inclined plane to connect the terrain surface 2 with the tube sole 17 in any case is necessary for a pipeline to be laid underground when the welding station is at surface level 2 is built.

3 shows a sectional view taken along the line III-III in 1 , The heap is recognizable 19 right and left of the pipeline route 4 , where the pipeline road 4 in the presentation of the 3 is perpendicular to the drawing plane. The heap 19 consists of the conveyed goods. The conveyed material consists essentially of the topsoil, which is stored in a heap, and the other excavation, which must be stored separately. For example, the topsoil on the left in the figure heap 19 and the other excavation on the right in the figure heap 19 be stored. In 3 is still a water level 27 located. Furthermore, the support roller 23 in plan view from the front to recognize schematically.

Hereinafter, the inventive method for laying a pipe is based on the 1 to 3 explained.

A first embodiment of the method according to the invention, in which the welding station is housed in a pit, is described below with reference to 1 explained. For laying a pipeline 1 consisting of several individual pipe sections 6 First, the starting pit 3 excavated. For lifting the starting excavation pit 3 In the context of the invention, all common methods and devices can be used. For example, an excavator can be used to lift the topsoil.

The starting excavation pit 3 is excavated so that their extension in the direction of the pipeline road 4 essentially the length of a pipe section 6 plus the length of the laser orbital welding station 7 having.

In a further step is at a distance 12 from the starting pit 3 a first propulsion pit 13 in a similar way as the starting pit 3 excavated. In both cases, the heap becomes 19 right and left next to the construction pits 3 . 13 on the ground surface 2 stored, wherein the topsoil is stored separately from the other excavation. In addition, between the starting pit 3 and the propulsion pit 13 the ditch 18 excavated. To dig the trench 18 is in the context of the invention, in principle, any known method suitable. It will be between all the construction pits 3 . 13 along the pipeline route 4 a coherent trench 18 excavated. In the context of the invention, it does not depend on the order in which the excavations or the trench are excavated.

The next step is the laser orbital welding station 7 in the starting pit 3 Installed. In addition, in the starting pit 3 as well as in each propulsion pit 13 a pipe pusher installed.

The construction site is now ready to receive the pipe sections. This is a first pipe section 6 into the starting pit 3 lowered. There is the pipe section 6 with the cheeks 9 of the pipe pusher 8th encompassed and not shown in the figures hydraulic cylinder in the trench 18 along the pipeline route 4 in the direction of the first jacking pit 13 propelled. The propulsion of the first pipe section 6 is done approximately until the rear end of the pipe section 6 in the area of the welding station 7 located.

Subsequently, another pipe section 6 into the starting pit 3 lowered until it is horizontally aligned and attached to the first pipe section 6 in the direction of the pipeline route 4 is arranged subsequently. In the laser orbital welding station 7 then become the ends of the two pipe sections 6 welded together in a single operation. As not further illustrated in the figures, in the laser orbital welding station 7 Furthermore, a quality control of the welded joint between the pipe sections 6 made by ultrasound or X-ray analysis. If necessary, the weld is repaired.

As also not shown in detail in the figures, in the laser orbital welding station 7 In addition, a corrosion protection applied to the weld. Suitable for corrosion protection a bituminous coating, sintering, a cement coating or a lamination.

As a result of this process step according to the invention are two pipe sections 6 connected together to form a pipe string. This from the two pipe sections 6 compound pipe string is now in turn with the help of Rohrpushers 8th along the pipeline route 4 in the prefabricated trench 18 propelled. If the pipe string has a length which is greater in total than the distance in total 12 between the starting pipe pit 3 and the propulsion pit 13 , the pipe string is also from the Rohrpusher 8th in the propulsion pit 13 with the help of the cheeks 9 embraced and also driven by this Rohrpusher. The entire driving force, which on the from the two pipe sections 6 existing pipe string, corresponds to the sum of the propulsive forces of the two Rohrpusher 8th ,

The propulsion of the pipe string is again approximately to one end of the pipe string approximately flush with a longitudinal edge of the starting excavation 7 is. Thereupon becomes another pipe section 6 into the starting pit 3 lowered and in the laser orbital welding station 7 welded to the tubing in the manner described above. Again, a quality control with ultrasound or X-ray is performed and applied a corrosion protection on the welded joint. Even after completion of this weld the now from three pipe sections 6 existing pipe string with the help of Rohrpusher 8th along the pipeline route 4 in the ditch 18 propelled. If the total length of the pipe string from the three pipe sections 6 is sufficient for this, the pipe string is now also by the in the second propulsion pit 13 existing pipe pusher 8th encompassed and driven on. In this case, both the Rohrpusher carry 8th in the starting pit 3 , as well as the pipe pusher 8th in the first propulsion pit 13 , as well as the pipe pusher 8th in the second propulsion pit 13 for propulsion of the pipe string 3 at.

The welding process in the laser orbital welding station 7 including quality assurance and trailing wrapping or creation of a corrosion protection can be carried out in a cycle time of about ten minutes in a single operation. In contrast, in conventional welding processes based on MAG welding (metal-active gas welding) usually several operations are required, which in the above-described conventional method for laying pipelines in five to six separate, along the pipeline line 4 must be carried out in succession established welding stations.

The Laser orbital welding process is therefore particularly good for carrying out the method according to the invention suitable because it can be performed with a compact device, which in the Starting pit can be installed.

In the manner described is a desired number of pipe sections 6 built to build the entire pipeline. This is with great advantage only on isolated, at intervals 12 mutually arranged excavations 3 . 13 a minimal Excavation in addition to the trench 18 necessary, so that the environment and / or agricultural production areas are spared as far as possible. Along the entire length of the pipeline route 4 only has a slot-like pipe trench 18 be dug. A further relief of the environment results from the elimination of a very wide strip of work around the pipeline route 4 around.

The working strip can be eliminated because of the use of the laser orbital welder 7 in the starting pit 3 a welding of the pipe sections 6 along the dike 18 eliminated. Instead, the welding takes place centrally only in the starting pit 3 , wherein in each case successively individual pipe sections 6 to the already in the ditch 18 existing pipe string to be welded. The use of the laser orbital welder 7 allows extremely short cycle times of about ten minutes for the welding process. The interaction of a variety of in driving excavation 13 installed pipe valves 8th allows the propulsion of the pipe string into the trench 18 also over several kilometers. It is particularly advantageous that the welding station 7 firmly in the starting pit 3 remains, with welding operations in this starting pit 3 or in several pits - to be performed. Also a material delivery and / or storage, especially of pipe sections 6 , is only in the vicinity of the starting pit 3 carried out. The environment and / or agricultural production areas are spared by this measure as far as possible.

In this way, according to the invention, a first method for laying a pipeline composed of a plurality of separate pipe sections along a pipeline route 4 proposed, which ensures minimal excavation and minimal surface use, and is suitable to produce and propel pipelines over several kilometers.

A further preferred embodiment of the method according to the invention is described below in connection with 2 explained. Deviating from the situation according to 1 this eliminates the lifting of a starting pit. Instead, become the first pipe pusher 8th and the welding station 7 outside the trench 18 above ground in a preparation area 20 on the terrain surface 2 established. Further, a feeder trench whose bottom is an inclined plane 25 has excavated. The reason of the trench has in the preparation area 20 the level of the terrain surface 2 and runs along the inclined plane 25 in increasing depth down to the level of the soil 17 of the trench 18 ,

After the feeder trench has been excavated with the described parameters, two pipe sections become above ground in the welding station 6 in the above-ground welding station 7 welded together to form a pipe string. Then this is made of two pipe sections 6 existing pipeline with the help of Rohrpushers 8th over the inclined plane of the feed trench in the trench 18 propelled. Due to the elasticity of the tubing string this is possible. The propulsion of the pipe string is stopped as soon as the rear end of the rear pipe section 6 within the welding station 7 has arrived.

At this stage, another pipe section 6 from the back (ie in the figure on the right) into the welding station 7 introduced and aligned with the tubing string. Subsequently, the further pipe section 6 welded to the tubing string. In addition, above ground - inside or outside the welding station 7 - the quality control and the corrosion protection measures made. The extended in this way pipe string is then with the Rohrpusher 8th over the inclined plane 25 of the supply trench in the trench pushed forward. The feed mechanism corresponds to that in connection with 1 explained. In this embodiment of the method according to the invention, the welding thus also takes place centrally only in the stationary preparation area 20 , However, it differs from the situation according to 1 the welding station is constructed above ground.

Both in the process variant according to 1 as well as in that according to 2 can be used according to the invention, the following measures to facilitate / improve the propulsion. To achieve a lateral guidance can in the trench 18 lateral guide rollers 22 be installed, which serve that the pipe string laterally not in contact with the side wall of the pipe trench 18 device, but minimizing friction from the lateral guide rollers 22 to be led.

Furthermore, on the ground 17 of the pipeline trench 18 in suitably chosen intervals supporting rollers 23 be installed, which support the pipe line during propulsion in the vertical direction and a direct abrasion of the pipe string on the ground 17 of the trench 18 prevent.

Finally, alternatively or in addition to the above-described measures to facilitate the propulsion of the trench 18 be flooded. Due to the buoyancy of the pipe string and because of the lubrication by the flood water As a result, the resistance during propulsion is reduced considerably. To prevent flooding of the trench 18 the launch pit and / or the propulsion ditches are also flooded, the annular seals are provided around the pipe string.

1

pipeline

2

ground surface

3

starting excavation

4

Pipeline route

5

longitudinal extension

6

pipe section

7

Laser orbital welding station

8th

pipe Pusher

9

to bake

10

linkage

11

abutment

12

distance

13

excavation pit

14

rear wall

15

slot

16

weld

17

invert

18

dig

19

heap

20

preparation area

21

annular seal

22

lateral leadership

23

supporting role

24

Plastic lid

25

Leaning level

26

water level

Claims (19)

Method for laying one of a plurality of separate pipe sections ( 6 ) composite pipeline ( 1 ) at an underground level ( 17 ) along a pipeline route ( 4 ), comprising the steps of: - digging a trench ( 18 ); - Making the pipeline on site by welding the pipe sections ( 6 ) together; - introducing the pipeline into the trench ( 18 ); Filling the trench, characterized in that the welding takes place stationary and the pipe string from the stationary welding station in the trench ( 18 ) is introduced. Method according to claim 1, characterized in that that the Pipe string over a section is inserted inclined. Method according to claim 1, characterized in that that the Pipe string from an excavation is introduced into the trench. Method according to one of the preceding claims, characterized in that the pipe string is pushed by means of a pushing device ( 8th ) is driven forward. Method according to one of the preceding claims, characterized in that the pipe string is introduced by train into the trench, in particular by pulling by means of at least one in one of the propulsion ditches ( 13 ) arranged pulling device is driven. Method according to one of the preceding claims, characterized characterized in that Pipeline led during insertion in particular, that the Pipe strand is driven by drivable transport rollers. Method according to one of the preceding claims, characterized characterized in that Pipe line is lubricated during insertion. Method according to one of the preceding claims, characterized characterized in that Pipeline is relieved of weight during insertion. Method according to one of the preceding claims, characterized characterized in that Pipe strand is driven when introduced at several points. Method according to one of the preceding claims, characterized characterized in that reaction forces when placing stationary be intercepted. Method according to one of the preceding claims, characterized characterized in that a Synchronization of the drives during insertion of the pipe string is done. Method according to one of the preceding claims, characterized characterized in that Pipe string when introducing at least one site for digging sealed off. Method according to one of the preceding claims, characterized in that - the excavation pit as start-up pit ( 3 ) is excavated, whose extension in the direction of the pipeline ( 4 ) substantially the length ( 5b ) of a separate pipe section ( 6 ) plus a working length required for carrying out the welding ( 5a ) receives; - along the pipeline route ( 4 ) in addition to the starting pit ( 3 ) at least one of these separate propulsion pit ( 13 ), which from the starting pit ( 3 ), as well as, if several propulsion ditches ( 13 ), to adjacent propulsion ditches ( 13 ) in an Ab was standing ( 12 ) is arranged; - between two excavations ( 3 . 13 ) along the pipeline route ( 4 ) digging through tube stroke ( 18 ) with a tubular sole ( 17 ) is lifted; - The pipeline successively in sections of separate pipe sections ( 6 ) into the starting pit ( 3 ) is lowered; - each pipe section ( 6 ) with the previously lowered pipe section ( 6 ) in the starting pit ( 3 ) welded to a pipe string and then into the trench ( 18 ) is driven forward. Method according to one or more of the preceding claims, characterized in that the pipe sections ( 6 ) are welded together by orbital welding and / or the pipe sections ( 6 ) using a laser welding method, preferably using an orbital welding device ( 7 ) are welded with a high-power fiber laser beam source and a laser welding head, and / or the pipe sections ( 6 ) are welded with a MAG welding process. Method according to one of the preceding claims, characterized characterized in that a quality control the weld, preferably by means of ultrasound or X-ray diagnosis is performed. Method according to one of the preceding claims, characterized characterized in that the welded joints be provided with a corrosion protection. Method according to one of the preceding claims, characterized in that the thrust for the introduction of the pipe string by means of a pusher device ( 8th ) in the starting pit ( 3 ) and / or in one or more propulsion ditches ( 13 ). Method according to one of the preceding claims, characterized in that the tubing string with jaws ( 9 ) is encompassed on a circumferential surface of the pipe string and, preferably hydraulically, pushed. Method according to one of the preceding claims, characterized characterized in that Ditch is flooded.