GB2467203A

GB2467203A - Railway track drilling

Info

Publication number: GB2467203A
Application number: GB0920737A
Authority: GB
Inventors: Andrew Woodgate
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-26
Filing date: 2009-11-26
Publication date: 2010-07-28
Anticipated expiration: 2029-11-26
Also published as: GB0920737D0; GB2467203B

Abstract

A method of replacing an existing pipe with a replacement pipe, the method comprising: positioning a drilling machine in a catchpit; operating the drilling machine to drive and guide the drill string in the replacement pipe bore; operating the drilling machine to extend the first end of the drill string into the inlet of the replacement pipe bore and through said bore to protrude from the outlet; fixedly attaching to the drill string a tricore tungsten carbide cutter (or similar) for grinding an milling the existing pipe; fixedly attaching a towing head to the swivel of the tricore tungsten carbide cutter; fixedly attaching the leading pipe which is pushed and bolted in to the towing head; operating the drilling machine to rotate and pull the drill string, causing the tricore tungsten carbide cutter to rotate and move laterally towards the outlet of the existing pipe bore.

Description

DESCRIPTION DOCUMENT

Description of correspondent: Railway Track Drilling

FIELD OF THE INVENTION

This invention relates to a particular method for replacement of buried pipe without the need to extract the pipe. In particular the invention involves a method for grinding existing buried clay pipe or brick culverts, which are in need of replacement. Into pulverised debris. The pulverised debris is washed through the interior section of the replacement pipe by a fluid lubricant. The installation of the replacement pipe, which is equal to or greater than the diameter of the existing pipe, is pushed by the Pipe pushing machine, which occurs simultaneously with the grinding of the existing buried pipe. The drilling machine utilises a method of a pulling force and a rotational force, for the grinding of the existing buried pipe. With a tricore cutter. Solid hex-bar drill rods are connected thereto and located within and through the existing pipe. The pulling force and rotational force applied by the drilling machine that is located in a catch pit. The pushing force applied by the pipe pushing machine is located in a corresponding catch pit.

The pulling force provided by the drilling machine pulls the tricore tungsten carbide cutter whilst simultaneously, the pushing machine pushes the replacement pipe horizontally through the bore of the existing pipe. The rotational force applied by the drilling machine to the drill string rotates the tricore tungsten carbide cutter, milling the existing pipe into granulated debris. The pipe pushing machine pushes the pipe together, which then assists in the horizontal linear movement of the replacement pipe.

BACKGROUND OF THE INVENTION

The present invention is, in general, applicable to replacement of clay salt glaze pipes, brick culverts, and concrete pipes. However, for illustrative purposes, the invention is discussed herein as it applies to the replacement of a clay salt glaze pipe.

A typical salt glaze pipe is sectioned. Each section having a spiggot and socket (male and female).

Salt glaze pipes deteriorate over time. Movement of the ground, vibration of trains and tree roots can cause cracking or for joints of salt glaze pipes to become disjointed. Salt glaze pipes which become disjointed or which become cracked, lose their function. Therefore need to be replaced to prevent surface water saturation, sponging, wet beds and flooding of the track. It is beneficial to provide a more cost effective means for the replacement of salt glaze pipes.

A conventional method of replacing salt glaze pipes consists of open cut methods over the length of the pipe to be replaced. Exposing the pipe, extracting the pipe and replacing the pipe with new. Streets, structures, and utility services (Railway tracks) lying over a pipe in need of replacement, often make excavation of the pipe non-viable or cost effective. Open cut methods for railway drainage are less viable because of time restraints, therefore this new method prevents segmented work and is significantly more cost effective.

A method of replacing a deteriorated existing pipe without interrupting overlying structures is to slide a flexible replacement pipe through the bore of the existing pipe.

However, such methods results in the utilisation of a replacement pipe which diameter is substantially less than that of the existing pipe, resulting in reduced carrying capacity. Often it is desirable or necessary to increase, rather than reduce the carrying capacity of the existing pipe. An increased carrying capacity requires that the diameter of the replacement pipe be equal to or greater than the diameter of the existing pipe. It is, therefore desirable to provide a method for replacing an existing salt glaze pipe with a replacement pipe which diameter is equal to or greater than that of the existing pipe. Without disturbing overlying structures and time restraints.

SUMMARY OF THE INVENTION

A feature of the invention described herein is to provide an innovative method for replacement of salt glaze pipes, brick culverts and concrete pipes. Wherein an existing pipe is milled into granulated debris by means of a tricore tungsten carbide cutter located within and through the existing pipe. The drill string being rotated and pulled by the drilling machine of the type typically used with Under Track Crossings (UTX) drilling systems. Which is mounted below ground level, attached at its opposite end a tricore tungsten carbide cutter. The rotation and pulling forces applied by the drilling machine to the drill string imparts rotational and horizontal motion to the tricore tungsten carbide cutter bit through the existing pipe, grinding, pulverising and removing the existing pipe. Whilst simultaneously the pipe pushing machine pushes into place the replacement pipe.

It is also a feature of this invention described herein to provide an innovative method for under ground pipe replacement, which permits replacement of the existing pipe with a replacement pipe. Having a diameter equal to or greater than the diameter of the existing pipe.

It is a further feature of this invention to allow pipe replacement operations to be conducted within a catch pit, or man hole (l200x600mm). Avoiding the need for an insertion pit.

It is another feature of this invention to provide an innovative method for pipe replacement wherein the grade or slope of the existing pipe is preserved and/or improved by the replacement pipe.

It is a further feature of this invention to allow pipe replacement to be conducted within a catch pit or manhole, avoiding the need of a drill stem insertion pit.

Further or other objects and beneficial attributes of the invention described herein will be apparent to those skilled in the art upon familiarisation of the disclosure herein.

The form of the invention herein described is illustrative of the function of the invention in general. The details of this disclosure are not to be construed as limiting the scope of the present invention.

The innovative aspects of this invention are accomplished through a back reaming and replacement pipe pushing operation, that occurs in one pass through the bore of an existing pipe, which is in need of replacement. To accomplish this, a catch pit or manhole is used at both ends of the section of pipe to be replaced. Pit A(inlet of pipe) serves the placement of the drilling machine insertion point, and Pit B (outlet of pipe), serves the placement of the pushing machine for the insertion of the replacement pipe.

The drilling machine is located below ground level in line with the existing pipe bore in Pit A. The pipe pushing machine is located below ground level in line with the existing pipe bore in Pit B. The drilling machine is capable of simultaneously applying rotational force and a pulling or pushing force to a successively jointed solid hex-bar drill string. It is also further capable of performing a fluid assist wherein a fluid is simultaneously pumped by the pump unit through the replacement pipe and into the front of the towing head.

The drill string is capable of electronic guidance through the ground, using a steering head guided by an electronic sensing and steering module, affixed to the leading drill string.

Once the steering head and guidance module of the leading drill string protrudes from the wall of Pit B, the steering head and guidance module are removed. The tricore tungsten carbide cutter (that has a diameter equal to or greater than the existing pipe) is attached to the leading rod of the drill string, followed by a pipe towing head, followed by the replacement pipe. The drill string is pulled simultaneously through the length of the section of existing pipe to be replaced until the end of the drill string protrudes into Pit A. The tricore tungsten carbide cutter, preferably is conical and has a helical cutting blade fixedly attached to its outer surface. The tricore tungsten carbide cutter contains a swivel, with a means fixedly such as a rotatable eye fixedly attached to its trailing end for towing a pulling head, without rotating the pulling head.

The drill string is attached to the tricore tungsten carbide cutter. The tricore tungsten carbide cutter is attached to the towing head (which has a plurality of apertures forming passages from the interior chamber to its outlet, which allows for the fluid to emit.) which is attached to the first pipe pushed and bolted in to the towing head.

With the mechanically connected sequence of the replacement pipe using the pipe pushing machine, the tricore tungsten carbide cutter, the drill string located within and through the existing pipe and the drilling machine in place, the back reaming and replacement pipe installation operation commences.

The pipe pushing machine applies a pushing force on the replacement pipes, as the Drilling machine simultaneously applies a pulling and rotational force to the drill string. This causes the tricore tungsten carbide cutter to rotate about the axis of the drill string, causing the tricore tungsten carbide cutter to move laterally into and through the bore of the existing pipe. Until protruding in to Pit A. Said lateral motion causes the helical blade of the tricore tungsten carbide cutter to come into contact with the existing pipe. Upon such contact, milling and pulverisation of the existing pipe takes place.

While the existing pipe is being ground away the hydraulic pump unit is operated to perform a fluid assist. In the fluid assist, a fluid composed of water and a polymer lubricant is mixed and pumped directly into the towing head via the replacement pipe, causing the fluid to emit at the front of the towing head. The fluid lubricates the helical blade of the tricore tungsten carbide cutter as it grinds the existing pipe. The fluid also lubricates the wall of the bore rearward of the back reaming bit reducing friction between bore and the replacement pipe. The fluid also causes pulverised debris from the existing pipe and surrounding ground to flow along the invert of the replacement pipe toward Pit B. The replacement pipe is pushed into and through the bore whilst grinding progresses.

Pulverised debris from the existing pipe flows toward Pit B via fluid assist. The fluid and debris emits as a slurry into Pit B, by means of backwash. The slurry will be pumped from Pit B for disposal. At completion of the process, the tricore tungsten carbide cutter emerges into Pit A followed by the towing head, followed by the replacement pipe. When the replacement pipe emerges into Pit A, the pipe replacement operation is complete.

The replacement pipe is segmented HDPE which is Dovelock.

The method of pipe replacement described above may only be accomplished through a single pass of back reaming. The replacement pipe is then pushed into and through the bore.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings appended hereto are submitted so that the features and objects of the invention briefly described above may be understood in further detail.

Such drawings illustrate only typical embodiments of the invention, and are not to be construed or considered as limiting in scope. The invention may admit other equally effective embodiments.

IN THE DRAWINGS

FIG. I is a sectional view illustrating above and below ground apparatus and equipment utilised in the method of this invention.

FIG. 2 is a sectional view of the drilling machine.

FIG. 3 is a sectional view of the tricore tungsten carbide cutter and towing head assembly demonstrating the process of grinding away an exisiting pipe, and simultaneously pushing a replacement nipe.

FIG. 4 is a a sectional view of the pipe pushing machine.

DETAIL AND DESCRIPTION OF PREFERRED EMBODIMENT

FIGURE 1 depicts a railway track (8) overlying an existing pipe (1), buried within the ground (9), in which the pipe is deteriorated and in need of replacement. The width of the rail way track (8) defines the length and location of the pipe (I) to which the method is applied. The slope or grade of the existing pipe (1) is determined between Pit A (36) and Pit B (37).

Referring to FIGURE 1, upon insertion of the hexbar drill rods (3) into the opening of the existing pipe (1), the Drilling machine is operated to further extend the hexbar drill rods (3) through the invert of the existing pipe (1).

Causing the end of the hexbar drill rods (3) to exit in to Pit B (37). A tricore tungsten carbide cutter (4) is fixedly attached to the end of the hexbar drill rods (3). Referring to FIGURE 3 the leading end of the tricore tungsten carbide cutter(4), preferably is conical and has a helical cutting blade fixedly attached to its outer surface. The tricore tungsten carbide cutter (4) contains a swivel (17), with a means fixedly such as a rotatable eye fixedly attached to its trailing end for towing a puing head (5), without rotating the pulling head (5).

Referring to FIGURE 1, segmented HDPE Dovelock pipe (6) is positioned in the pipe pushing machine (7), in Pit B (37). Referring to FIGURE 3, the replacement segmented HDPE Dovelock pipe (6) is fixedly attached to the towing head (5), which is fixedly attached to the swivel (17), which is fixedly attached to the tricore tungsten carbide cutter (4).

Referring to FIGURE 1, the Drilling machine (2) is then operated to apply a pulling force to the hexbar drill rods (3), which in turn pulls back the tricore tungsten carbide cutter (4) laterally into the outlet of the existing pipe (1).

Simultaneously, whilst applying such pulling force, the Drilling machine (2) is operated to apply rotational force to the hexbard drill rods (3), causing the tricore tungsten carbide cutter (4) to rotate. Referring to FIGURE 3, the lateral pulling and rotational force transmitted through the hexbar drill rods (3) to tricore tungsten carbide cutter (4) enabling the gringing of the existing pipe (1) in to slurry (18).

Simultaneously with the grinding of the existing pipe (1), the Pipe pushing machine is operated to perform a fluid assist wherein a fluid is composed of a water and polymer lubricant. Referring to FIGURE 3 and 4, such pumping causes the fluid to pass through the flexible high pressure hose (25). The fluid is then emitted from the jeweled jets (20). The fluid also lubricates the wall of the newly formed pipe bore (40) rearward of the tricore tungsten carbide cutter (4) reducing friction between newly formed pipe bore (40)and the replacement segmented HDPE Dovelock pipe (6).

The fluid also causes pulverised debris from the existing pipe and surrounding ground to flow along the invert of the replacement segmented HDPE Dovelock pipe (6) toward Pit B (7).

Referring to FIG. 3, the grinding operation of the tricore tungsten carbide cutter (4) creates a newly formed pipe bore (40). The diameter is sufficient to allow the segmented HDPE Dovelock pipe (6) to be simultaneously pushed through the newly formed pipe bore (40) by the pipe pushing machine (7). The process of grinding away the existing pipe (1) and simultaneously pushing the segmented HDPE Dovelock pipe (6) into the newly formed pipe bore (40) continues until the tricore tungsten carbide cutter (4) and the end of the replacement segmented HDPE Dovelock pipe (6) emerges in to Pit A (36). Once the replacement pipe emerges into Pit A (36), the pipe replacement process is complete.

In view of the foregoing, it is evident that the present invention is one well adapted to obtain all of the objects and features hereinabove set forth together with other objects and features that are inherent from the method described hereinabove.

While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow