GB1566419A

GB1566419A - Shaft raising

Info

Publication number: GB1566419A
Application number: GB5341776A
Authority: GB
Original assignee: Taylor Woodrow Construction Ltd
Current assignee: Taylor Woodrow Construction Ltd
Priority date: 1978-01-11
Filing date: 1978-01-11
Publication date: 1980-04-30

Description

(54) SHAFT RAISING (71) We, TAYLOR WOODROW CONSTRUCTION LIMITED, a British Company, of 345, Ruislip Road, Southall, Middlesex UB1 2QX., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the followmg statement: This invention relates to the formation and of lining of upwardly extending shafts.

According to the present invention there is provided a method lining an upwardly extending shaft by arranging a series of lining rings one above the other within the shaft using a platform movably supportable within the shaft above which platform is provided a jack girder connectible to the platform by means of a holding jack mechanism, there being provided a ram girder, positioned between the jack girder and the platform and connected to the jack girder by means of a main jack mechanism; the method comprising, for one ring, the steps of: (a) with the platform stationary, sup- ported within the shaft, and with the ram girder supported on an uppermost lining ring previously positioned within the shaft, extending the main jack mechanism to raise the jack girder through a distance which is not less than the axial thickness of the lining ring to be positioned; (b) supporting the jack girder on the platform by means of the holding jack mechanism, and retracting the main jack mechanism to raise the ram girder through said distance; (c) forming the lining ring from a plurality of arcuate sections upon the uppermost previously positioned lining ring; and (d) retracting the holding jack mechanism with the ram girder resting on the newly positioned lining ring to cause the platform to be raised to a new position in readiness for the repetition of steps (a) to (d) for a succeeding lining ring with said newly positioned lining ring constituting said uppermost previously positioned lining ring.

The invention also provides a method of simultaneously raising and lining an underground upwardly extending shaft comprising the method as just defined and in which step (a) includes excavating sufficient material from above the jack girder to allow the jack girder to be raised through said distance.

The invention further provides a method of simultaneously forming and lining an underground upwarding extending shaft which is to pass through a first, lower, region comprising rock and/or clay and a second, upper, region comprising sand, the method comprising, for forming and lining the shaft in the first region, the method as set forth in the immediately preceding paragraph, and then, for forming and lining the shaft in the second region. the steps of:: (i) mounting the platform within the shaft at a position formed and lined using the last-mentioned method; (ii) with the ram girder supported on the uppermost lining ring positioned using said last-mentioned method, extending the main jack mechanism to move the jack girder upwardly thereby to force a cap support member, and hence a cap supported on this cap support member, upwardly into the sand by a distance which is not less than the axial thickness of the lining ring to be positioned; (iii) supporting the cap support member with the holding jack mechanism and retracting the main jack mechanism to lower the jack girder; (iv) forming a lining ring from a plurality of arcuate sections upon the jack girder; and (v) retracting the holding jack mechanism to allow the cap to be supported by the newly formed ring and the cap support member to be engaged with the newly formed ring; steps (ii) to (v) thereafter being repeated, for each subsequent lining ring, to lift, inter alia, each newly formed ring.

The invention also provides apparatus for use in lining an upwardly extending shaft by arranging a series of lining rings one above the other within the shaft, the apparatus comprising a platform adapted to be movably supported in a shaft, a jack girder connectible to the platform by means of a holding jack mechanism, and a ram girder disposed between the platform and the jack girder and connected to the jack girder by means of a main jack mechanism, the main jack mechanism being operable to raise the jack girder through a distance not less than the axial thickness of any one of the lining rings to be arranged in the shaft.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figures 1 to 10 show successive conditions of apparatus during operation thereof to raise a shaft, and Figure 11 is a cross-section taken along the line XI-XI of Figure 10.

Figures 1 to 10 illustrate a procedure for raising a 3.4 m diameter shaft about 40 m vertically upwardly from an underground tunnel through a first region of rock and clay (Figures 1 to 6) and then through a second region of waterlogged sand (Figures 7 to 10). Such conditions may be encountered, for example, when raising a shaft through the sea bed from a tunnel below the sea bed.

It may be necessary to raise such a shaft during the construction of a cooling water intake or outfall for a plant such as a power station or a steel works. The shaft is lined, as the raising proceeds, with concrete lining rings in the first region and with steel lining rings in the second region.

In the following description of the apparatus used to raise the shaft it should be noted that, although the apparatus shown in Figures 7 to 10 differs slightly from that shown in Figures 1 to 6, the same apparatus could be used throughout.

The apparatus includes a platform 2 which can be supported at different vertical levels in a shaft 1, a ram girder 4, a jack girder 6, a cap support member 8 and a cap 10. The jack girder 6 is releasably secured to the cap support member 8 which is connected to the platform 2 by three holding jacks 12 (only one of which is shown in Figure 1) of a holding jack mechanism. The ram girder 4 is connected to the jack girder 6, between the jack girder and the platform 2, by six main jacks 14 (again, only one is shown in Figure 1) of a main jack mechanism. The number of holding jacks 12 and main jacks 14 required will depend on the power of each jack and the soil conditions in which the shaft is to be raised. More or fewer jacks may be necessary.

The cap 10 is composed of a nose 16 and a seal plate ring 18 provided with a hatch (not shown). The nose 16 affords protection for equipment and personnel in the shaft 1 as excavation of the upper end 20 of the shaft proceeds. The seal plate ring 18, in conjunction with the shield skin 22 that surrounds the components 4, 6, 8 and 10, affords a water-tight casing, which is necessary if the apparatus is to be used for raising a shaft through the sea bed. The shield skin 22 is fixed to the jack girder 6 and also affords a temporary lining for the newly formed region of the shaft.

In the initial condition shown in Figure 1, the platform 2 is bolted to a ring 23 within the shaft 1 below a lining ring 24 which has just been positioned and immediately below a further lining ring 26 which was positioned just before the ring 24. The ram girder 4 is supported on the ring 24. All the jacks 12, 14 are retracted.

The rock or clay above the nose is then removed (Figure 2), for example by blasting in rock and overhead excavation in clay, to raise the height of the upper end 20 of the shaft until there is enough room to raise the nose 16 by a distance (say about 650 mm) which is not less than the axial thickness of the lining rings (600 mm). As illustrated in Figure 3, the main jacks 14 and the holding jacks 12 are then extended to raise the jack girder 6, the cap support member 8, the cap 10 and the shield skin 22 by about 650 mm until the cap 10 is close to or contacts the rock or clay.

The cap support member 8 and the jack girder 6 are then supported by the holding jacks 12 while the main jacks 14 are retracted (Figure 4). This raises the ram girder 4 off the ring 24, leaving a space 25 between the ring 24 and the ram girder 4 to accommodate a new ring. Before the new ring is positioned, the space 27 between the excavated rock and the outer periphery of the last-placed ring 24 is grouted. This grouting must not extend higher than the bottom edge of the shield skin 22.

A new concrete lining ring 28 (Figure 5) is then formed by bolting together a number of arcuate sections above the ring 24 and the ram girder 4 is lowered onto this new ring 28 by slightly extending the main jacks 14.

Finally (Figure 6) the platform 2 is unbolted from the ring 23 and raised, by retracting the holding jacks 12, to a new position at which it is boted to the ring 26. The apparatus is then again in its initial condition, but has been raised by the width of one ring. The cycle as just described may be repeated as often as required for placing successive lining rings.

When, in operating through the sea bed, the nose 16 approaches the second region of waterlogged sand, the way in which the shaft is raised and lined changes. One reason for this is that as waterlogged sand is not solid, like rock and clay, but behaves like a liquid, excavation is not possible but the nose can be forced through the sand using the main jacks.

When the second region is reached, the platform 2 is moved up and bolted to the uppermost concrete ring 30 (Figure 7) which has been positioned as described with reference to Figures 1 to 6. The platform 2 remains in this position whilst the raising of the shaft is completed. The cap support member 8, whilst remaining releasably connected to the jack girder 6 is in the apparatus illustrated in Figures 7 to 11 also releasably connected to the adjoining flanges of the seal plate ring 18 and a cast iron ring 32.

The shield skin 22 is detached from the jack girder 6 and the gap between it and the excavated rock and clay is grouted. The shield skin 22 is thus permanently fixed in position. This is the condition shown in Figure 7.

The main jacks 14 and the holding jacks 12 are then extended (Figure 8) to push the cap support member 8, ring 32, seal plate ring 18 and cap 10 out from the shield skin 22 into the waterlogged sand. The shaft may be pressurised at about 30 pounds per square inch to prevent water from seeping into the shaft through any apertures, and the effect of escaping air from the shaft causes the sand to "boil" which allows the nose to be pushed through the sand relatively easily.

When the nose 16 has been pushed up by a distance not less than the thickness of a lining ring, the main jacks 14 are retracted whilst the cap support member 8 is supported on the holding jacks 12. The jack girder 6, which has been released from the cap support member 8, is thus lowered to leave a gap between it and the cap support member 8 in which a new steel lining ring 34 may be assembled from arcuate sections, which are bolted together (Figure 9). This new ring 34 is supported on the jack girders 6. The holding jacks 12 are then retracted until the ring 32 is supported on the newly positioned lining ring 34. The cap support member 8 is released from the adjoining flanges of the rings 18 and 32, lowered further, and connected to the adjoining flanges of the rings 32 and 34 (Figure 10).

The cycle may then be repeated to lift the ring 34 and position another ring beneath the ring 34, and so on as required.

When the shaft has been raised to its full extent, i.e. when the surface of the sea bed is reached, the interior of the shaft remains dry due to the seal plate ring 18. The main jacks 14 and the holding jacks 12 are extended to leave enough room betwen tha ram girder 4 and the jack girder 6 to accommodate one more lining ring, which is then fitted in position. The platform 2, the cap support member 8 and the jacks 12 and 14 are removed from the shaft 1, and the jack girder 6 and the ram girder 4 are cut to shape to afford further lining rings. The original shape of the ram girder 4 can be seen from Figure 11, and it will be appreciated that the three segment-shaped parts 36 must be cut out to leave the outer ring 38. It will be appreciated that once the jack girder 6 and the ram girder 4 have been cut to shape, the shaft will, effectively, be completely lined from top to bottom.An inner lining is then provided over the internal periphery of the rings to give a smooth internal surface to the shaft. This inner lining may be formed, for example, by slip formed concrete work.

Any necessary work at the upper end of the shaft, for example the removal of the nose 10 and the provision of any valves, may be carried out by divers. The divers can then break through the seal plate ring 18 and the shaft may be flooded.

In the description with reference to Figures 1 to 6, the platform 2 and the ram girder 4 are described as being supported on lining rings already in position in the shaft.

However, in the intial stages of raising the shaft from a tunnel, the platform 2 will be supported on a power platform on the tunnel floor which will serve progressively to raise the platform 2 as more and more lining rings are positioned in the shaft until enough rings are present to support the platform 2 and the ram girder 4 in the way described.

In the description, the lining rings in the first region are referred to as being of concrete while those in the second region are referred to as being of steel. However, all the rings could be of concrete or all of steel, or any other material suitable to the environment in which the shaft lining is being formed.

WHAT WE CLAIM IS: 1. A method of lining an upwardly extending shaft by arranging a series of lining rings one above the other within the shaft using a platform movably supportable within the shaft above which platform is provided a jack girder connectible to the platform by means of a holding jack mechanism, there being provided a ram girder, positioned between the jack girder and the platform and connected to the jack girder by means of a main jack mechanism;

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ring. The cycle as just described may be repeated as often as required for placing successive lining rings. When, in operating through the sea bed, the nose 16 approaches the second region of waterlogged sand, the way in which the shaft is raised and lined changes. One reason for this is that as waterlogged sand is not solid, like rock and clay, but behaves like a liquid, excavation is not possible but the nose can be forced through the sand using the main jacks. When the second region is reached, the platform 2 is moved up and bolted to the uppermost concrete ring 30 (Figure 7) which has been positioned as described with reference to Figures 1 to 6. The platform 2 remains in this position whilst the raising of the shaft is completed. The cap support member 8, whilst remaining releasably connected to the jack girder 6 is in the apparatus illustrated in Figures 7 to 11 also releasably connected to the adjoining flanges of the seal plate ring 18 and a cast iron ring 32. The shield skin 22 is detached from the jack girder 6 and the gap between it and the excavated rock and clay is grouted. The shield skin 22 is thus permanently fixed in position. This is the condition shown in Figure 7. The main jacks 14 and the holding jacks 12 are then extended (Figure 8) to push the cap support member 8, ring 32, seal plate ring 18 and cap 10 out from the shield skin 22 into the waterlogged sand. The shaft may be pressurised at about 30 pounds per square inch to prevent water from seeping into the shaft through any apertures, and the effect of escaping air from the shaft causes the sand to "boil" which allows the nose to be pushed through the sand relatively easily. When the nose 16 has been pushed up by a distance not less than the thickness of a lining ring, the main jacks 14 are retracted whilst the cap support member 8 is supported on the holding jacks 12. The jack girder 6, which has been released from the cap support member 8, is thus lowered to leave a gap between it and the cap support member 8 in which a new steel lining ring 34 may be assembled from arcuate sections, which are bolted together (Figure 9). This new ring 34 is supported on the jack girders 6. The holding jacks 12 are then retracted until the ring 32 is supported on the newly positioned lining ring 34. The cap support member 8 is released from the adjoining flanges of the rings 18 and 32, lowered further, and connected to the adjoining flanges of the rings 32 and 34 (Figure 10). The cycle may then be repeated to lift the ring 34 and position another ring beneath the ring 34, and so on as required. When the shaft has been raised to its full extent, i.e. when the surface of the sea bed is reached, the interior of the shaft remains dry due to the seal plate ring 18. The main jacks 14 and the holding jacks 12 are extended to leave enough room betwen tha ram girder 4 and the jack girder 6 to accommodate one more lining ring, which is then fitted in position. The platform 2, the cap support member 8 and the jacks 12 and 14 are removed from the shaft 1, and the jack girder 6 and the ram girder 4 are cut to shape to afford further lining rings. The original shape of the ram girder 4 can be seen from Figure 11, and it will be appreciated that the three segment-shaped parts 36 must be cut out to leave the outer ring 38. It will be appreciated that once the jack girder 6 and the ram girder 4 have been cut to shape, the shaft will, effectively, be completely lined from top to bottom.An inner lining is then provided over the internal periphery of the rings to give a smooth internal surface to the shaft. This inner lining may be formed, for example, by slip formed concrete work. Any necessary work at the upper end of the shaft, for example the removal of the nose 10 and the provision of any valves, may be carried out by divers. The divers can then break through the seal plate ring 18 and the shaft may be flooded. In the description with reference to Figures 1 to 6, the platform 2 and the ram girder 4 are described as being supported on lining rings already in position in the shaft. However, in the intial stages of raising the shaft from a tunnel, the platform 2 will be supported on a power platform on the tunnel floor which will serve progressively to raise the platform 2 as more and more lining rings are positioned in the shaft until enough rings are present to support the platform 2 and the ram girder 4 in the way described. In the description, the lining rings in the first region are referred to as being of concrete while those in the second region are referred to as being of steel. However, all the rings could be of concrete or all of steel, or any other material suitable to the environment in which the shaft lining is being formed. WHAT WE CLAIM IS:

1. A method of lining an upwardly extending shaft by arranging a series of lining rings one above the other within the shaft using a platform movably supportable within the shaft above which platform is provided a jack girder connectible to the platform by means of a holding jack mechanism, there being provided a ram girder, positioned between the jack girder and the platform and connected to the jack girder by means of a main jack mechanism;

the method comprising, for one ring, the steps of: (a) with the platform stationary, supported within the shaft, and with the ram girder supported on an uppermost lining ring previously positioned within the shaft, extending the main jack mechanism to raise the jack girder through a distance which is not less than the axial thickness of the lining ring to be positioned; (b) supporting the jack girder on the platform by means of the holding jack mechanism, and retracting the main jack mechanism to raise the ram girder through said distance; (c) forming the lining ring from a plurality of arcuate sections upon the uppermost previously positioned lining ring: and (d) retracting the holding jack mechanism with the ram girder resting on the newly positioned lining ring to cause the platform to be raised to a new position in readiness for the repetition of steps (a) to (d) for a succeeding lining ring with said newly positioned lining ring constituting said uppermost previously positioned lining ring.

2. A method of simultaneously raising and lining an underground upwardly extending shaft comprising the method as claimed in claim 1 and in which step (a) includes excavating sufficient material from above the jack girder to allow the jack girder to be raised through said distance.

3. A method of simultaneously forming and lining an underground upwardly extending shaft which is to pass through a first, lower, region comprising rock and/or clay and a second upper, region comprising sand, the method comprising, for forming and lining the shaft in the first region, the method as claimed in claim 2, and then, for forming and lining the shaft in the second region, the steps of:: (i) mounting the platform within the shaft at a position formed and lined using the last-mentioned method; (ii) with the ram girder supported on the uppermost lining ring positioned using said last-mentioned method, extending the main jack mechanism to move the jack girder upwardly thereby to force a cap support member and hence a cap, supported on this cap support member, upwardly into the sand by a distance which is not less than the axial thickness of the lining to be positioned; (iii) supporting the cap support member with the holding jack mechanism and retracting the main jack mechanism to lower the jack girder: (iv) forming a lining ring from a plurality of arcuate sections upon the jack girder; and (v) retracting the holding jack mechanism to allow the cap to be supported by the newly formed ring and the cap support member to be engaged with the newly formed ring; steps (ii) to (v) thereafter being repeated for each subsequent lining ring, to lift, inter alia, each newly formed ring.

4. A method of simultaneously raising and lining an underground upwardly extending shaft, substantially as hereinbefore described with reference to the accompanying drawings.

5. Apparatus for use in lining an upwardly extending shaft by arranging a series of lining rings one above the other within the shaft, the apparatus comprising a platform adapted to be movably supported in a shaft, a jack girder connectable to the platform by means of a holding jack mechanism, and a ram girder disposed between the platform and the jack girder and connected to the jack girder by means of a main jack mechanism, the main jack mechanism being operable to raise the jack girder through a distance not less than the usual thickness of any one of the lining rings to be arranged in the shaft.

6. Apparatus as claimed in claim 5, wherein a cap support member for a cap is connected to the platform by the holding jack mechanism and the jack girder is releasably connected to the cap support member between the cap support member and the platform.

7. Apparatus as claimed in claim 6, wherein the cap support member carries a cap that is adapted to provide a cover for personnel and equipment within the shaft, and that is adapted to be forced through sand during raising of the shaft

8. Apparatus as claimed in any one of claims 5 to 7, wherein a shield is attached for movement with the jack girder to afford a temporary lining of the shaft at the region of the jack girder before the shaft is lined with lining rings.

9. Apparatus for use in lining an upwardly extending shaft by arranging a series of lining rings one above the other within the shaft, the apparatus being substantially as hereinbefore described with reference to the accompanying drawings.