GB2261687A - Improvements in or relating to piling and pipe lining - Google Patents

Abstract

During pipe lining in which a liner pipe 32 is moved into a pipe 13 to be lined, chambers 10,11 are formed in the ground at the ends of pipe 13. Piles 19 are guided during insertion into the ground by structure 16 extending between chambers 10, 11 on both sides thereof. Each structure 16 has laterally inner and outer parts on opposite side of piles. The structures 16 support a guide roller 22 for the liner 32 and a pivotable frame 15 supporting a liner die 14. The structures 16 are in modular form and support a winch mast 30 associated with a winch 26 for pulling the liner through pipe 13. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO PILING AND PIPE LINING This invention relates to piling and pipe lining.

According to this invention apparatus for piling comprises structure for guiding a pile during insertion into the ground.

The structure may be elongate transverse to the pile.

There may be structure on opposite sides of the pile.

There may be spaced piles each having such a structure, with the structures being connected.

The structure may support a guide roller for a liner during pipe lining.

The structure may support a frame for a die through which a liner moves during pipe lining. The frame may be pivotable with respect to the structure.

A winch device may include a mast secured to such a structure, and bracing means may be operatively engaged with piles associated with the structure.

The invention provides a method of piling comprising guiding the pile during insertion into the ground.

The invention may be performed in various ways and one specific embodiment with possible modifications will now be described by way of example with reference to the accompanying diagrammatic drawings, in which: Fig.l is a side view of part of pipe lining apparatus; Fig.2 is a side view of another part of the apparatus; Fig.3 is a cross-section through a trench; Fig.4 is a view of an outer pile frame; Fig.5 is a view of an inner pile frame; Fig.6 is a cross-section showing a die frame; Fig.7 is a side view of the die frame; and Fig.8 is part of Fig.2 on an enlarged scale.

In lining a buried pipe, for example a gas or water pipe, a chamber is dug in the ground at the ends of a length of pipe that is to be lined, and a plastics liner pipe is moved through a die, which reduces the diameter of the liner, and into the buried pipe under tension. The tension is then released and the liner recovers in diameter to engage firmly the inner surface of the buried pipe. During the recovery in liner diameter, the length of the liner becomes less. A succession of adjacent lengths of pipe can be lined and the adjacent ends of the liner pipes are joined together to form a continuous liner pipe. The chambers are then backfilled.

The present arrangement is suitable for such pipe linings.

Chambers 10, 11 are formed in the ground 12 at the ends of the length of pipe 13 which is to be lined.

A die 14 is mounted in a frame 15 which is supported on structure 16 which is supported on the ground 12.

The structure or the piling frame 16 is at each side of the trench or chamber 10,11 and has inner and outer parts 17,18 which act as guides for the insertion of interlocking piles 19 which form a lining to the sides of the chambers 10,11.

Walings 20 are provided and have hydraulic waling jack struts 21 as required.

A guide roller 22 is supported on a frame 23 from the structure 16 to guide the liner pipe 32. The die frame 15 is pivotally mounted on structure 16 at 24 and can be pivoted by jack 25 to a desired position.

A winch 26 operates winch cable 27 which extends around rollers 28,29, mounted on a winch mast 30, which is supported by structure 16, and connects to a fastener 31 at the front end of the liner 32.

At the lower end of the mast 30 a frame 33 transfers the thrust loading to waling 34,20.

As shown in Fig.l the chamber 10 is stepped as at 34, In the example of Fig.l, the bending radius of the liner 32 is about 40 times the liner diameter, and the die frame 15 has been set down at into the end of the trench to reduce the approach angle. This also keeps the liner pipe close to the ground for ease of handling and safety, and generally reduces drag (and therefore the winch tension).

In Fig. 1, piling frames, walings and two piles have been shown. The walings are capable of supporting the piles over at least 6 metre lengths without strutting, and the positioning of the strutting is flexible so that individual struts can be placed wherever necessary to suit the actual position of the liner. This Fig also shows examples of the vector forces Tw (winch) and Tr (roller) that may be imposed upon the piling frames by the winching operation.

Fig.3 shows a typical cross section, indicating for example a 2 metre clearance between walings for equipment access, and also shows the piles toed in below the trench invert 37. This may not be possible if the pipe trench has been excavated in rock, and the piles are capable of providing cantilever trench wall support below the level of the walings. Fig.2 shows the location and bracing of the winch mast, utilising an extra waling near the trench bottom and thrust transfer frames which will take the thrust (up to 40 tonnes) transmitted from the bottom of the winch mast by pivoting bracings 38.

Because of the need to locate the winch mast bracings, the die frame and the guide roller for each insertion, it is of advantage if the geometry of the mountings is the same each time. The piling frame system is therefore designed so that it cannot be assembled out of alignment, nor be pushed out of alignment by the forces encountered during pile driving.

As all the equipment has to be transported along the pipe route from chamber to chamber as lining progresses, it is preferable that it can be easily handled and transported. All items are provided with suitable lifting points located above their centre of gravity, so that they are easy to handle and align.

The piling frame structure 16 has a modular construction giving ample stiffness in both vertical and horizontal planes. The component parts are as light as possible, consistent with being strong enough to withstand the forces applied during operation, and robust enough. The dimensions shown are examples.

In assembly coupling pins are used. These pins are of generous size and of design to withstand being repeatedly driven in and out, and may be held captive by way of heavy duty chain. A pin is shown at 50.

The structure 16 has two types of frame, an outer and an inner, shown in Figs.4,5. These Figs show a fully welded lattice type construction, but alternative types of construction may be used. All the outer frames 40 are the same, so as to be fully interchangeable, as will be the inner frames 41, which will incorporate mountings for the die frame, guide roller, struts and puncheons. A typical assembly would employ ten of each frame (used five per side).

The couplings 42,50 are able to transfer the considerable loadings that may occur in service, into the main structure of the frame.

The piling frames perform two primary functions.

As they will normally sit directly upon the ground, they will not initially need to apply any thrust to prevent ground movement, and their first function will be to provide precise location and alignment for the piles. As the excavation of the chambers 10,11 proceeds, a certain amount of ground thrust will occur, but will be taken mostly by the walings, and their second function will be to provide a structural frame work to transfer the die-drawing forces to the anchorage of the piles. Only in very bad ground conditions, will they be required to perform a secondary function of ground support The inner frames are joined together top and bottom by fixed length struts 43. It will be seen from Fig.l that three bottom struts and one top strut are left out at the die frame end, but as there will be no piles in this section of the piling frame, the necessary rigidity is provided by linking the inner frames to the outers.

Struts 43 are located as desired, preferably regularly.

If it is desired to provide continuous interlocking pile barrier against the ingress of water, it will not normally be possible to link the inner and outer piling frames other than beyond the extremities of the pile curtains. Both the inner and outer piling frames will possess considerable rigidity in all three axes, so intermediate linking should not be necessary, though links could be accommodated by slotting the top sections of selected piles.

For accurate placement it is desirable to provide a good sliding fit to the piles as they are inserted, and the inner frame is therefore provided with 'bolt on' liner guide plates indicated at 44 to fit the actual type of pile used. This allows alternative types of pile to be used simply by changing the guide plates.

During die-drawing operations, the inner frames are tightly clamped to the piles, as the transfer of diedrawing forces to the pile anchorage will depend upon the frictional grip between piles and frames. It may be that such 'clamping' is inherent in the system, but if this is not so, a suitable clamping mechanism is incorporated into the inner piling frame and liner guide system which could be either manually or hydraulically operated, indicated schematically at 45.

The walings 20 are the same length as the piling frames. The walings are provided with attachments 46 for puncheons to match attachments 46a on the bottom edge of the inner piling frames. The puncheons themselves are of adjustable length to cope with a substantial variation in waling position.

The hydraulic struts 21 are capable of easy fitting and removal, and it is possible to replace them in any position along the walings. It is possible to assemble pairs of walings as a frame by temporarily locking two struts into position, so that the walings can be inserted and put into service without an operative having to enter the trench.

The typical trench arrangement shown in Fig.l provides some 14 metres of liner for recovery at the end of the insertion, but in the case of long runs, this may not be sufficient. To cater for this situation, the die frame can be moved back in 4 metre steps by simply adding sections to the piling frame.

To avoid having to extend the excavation, the die frame can be raised clear of the ground by turning the final inner frames the other way up, thus placing the mountings towards the top of the frames rather than the bottom.

In order that the die-drawing equipment is accurately aligned with the pipe and correctly positioned in relation to the pipe joints, the ground support installation and associated excavation is carried out in accordance with the following method, which describes the sequence of operations in excavating and setting up a typical (entry) chamber 10: The exact line of the pipe 13 is first determined, so that the centre line of the chamber can be set out.

Starting at one end, a pilot excavation is carried out down to the crown of the pipe 13, extended along the centre line until a pipe joint is reached, and then extended a further 500mm beyond it. The 'far end of the chamber can be set out at this point.

Another pilot excavation is then made at the other end of the excavation, digging some 12 metres back from the first pipe joint so that a second pipe joint crown is exposed, and then extended a further 500mm beyond it. The near end of the chamber, which will be 13 metres long, can be set out at this point.

The end of the piling frames extend for example 1.5 metres beyond the end of the chamber (2 metres beyond the pipe joint) so the first pair of inner frames is set up in that position symmetrically spaced about, and parallel with, the centre line, and joined together with fixed length struts top and bottom.

The first pair of outer frames are then placed in position outside the inner frames and coupled to them at each end, thus forming a piling frame 4 metres long.

Piles are then driven at all four corners of the piling frame to a sufficient depth to hold it firmly in position during the pile driving operation, after which piles are driven progressively along both sides of the piling frame, taking care to maintain good vertical alignment.

Excavation is then carried out to the full depth rewired, starting from the far end, and continuing up to about 500mm from the near end of the piling frame.

The second pair of inner frames is then coupled to the first pair, and the internal struts fitted. The second pair of outer frames is then coupled to the first pair, and coupled to the inner frames at the near ends.

A couple of piles are part driven at the near ends of the second section to hold it in place.

Piles are then driven progressively along both sides of the second section, removing the couplings between the inner and outer frames as they are reached, and the whole sequence repeated until the fourth section has been completed. The first walings are inserted immediately excavation of the second section has proceeded far enough.

The final frame sections are coupled to the fourth sections, and the inners and outers coupled together, after which the excavation is extended a further 7 metres to a depth of 1 metre and width of 2 metres to accommodate the die frame, which can then be on its mountings.

One of the exposed pipe sections is cut out, after which any remaining pipe sections may be removed intact. The trench bottom can be trimmed and a sump dug at each end for ground water pumping. The guide roller is then located on its mountings.

Tr may for example be up to 10 tonnes.

Tw may for example be up to 40 tonnes.

The arrangement above provides a method of piling comprising guiding the pile during insertion into the ground. The guide structure is separate from the piles; is on both sides of the piles and is on both sides of the excavated chamber.

Claims (11)

1. Apparatus for piling comprising structure for guiding a pile during insertion into the ground.

2. Apparatus as claimed in Claim 1, in which the structure is elongate transverse to the pile.

3. Apparatus as claimed in Claim 1 or Claim 2, in which the structure is on opposite sides of the pile.

4. Apparatus as claimed in any preceding claim, comprising spaced piles each associated with a said structure.

5. Apparatus as claimed in any preceding claim, in which the structure supports a guide roller for a liner for pipe lining.

6. Apparatus as claimed in any preceding claim, in which the structure supports a frame for a die for a liner for pipe lining.

7. Apparatus as claimed in Claim 6, in which the frame is pivotable with respect to the structure.

8. Apparatus as claimed in any preceding claim, including a winch mast secured to the structure.

9. Apparatus as claimed in Claim 8, including bracing means operatively engaged with piles associated with the structure.

10. Apparatus for piling substantially as herein before described with reference to and as shown in the accompanying drawings.

11. A method of piling comprising guiding the pile during insertion into the ground.