US2385251A - Tunneling method - Google Patents

Description

Sept. 18, 1945- F. 'P. AYERS TUNNELING- METHOD Filed Nov. 22, 1944 5 Sheets- Sheet 1 ,1 F. RAYERS 4 2,385,251

TURNELING METHOD Filed Nov. 22, 1944 5 Sheets-Sheet 2 Fig.2.

Sept. 18, 1945. r F. P. AYERS 2,335,251

TUNNELING METHOD Filed Nov. 22, 1944 '5 Sheets-Sheet 4 Se pt. 18, 19.45. F. P. AYERS. 2,385,251

' TUNNELING METHOD Filed Nov. 22, 1944 5 Sheets-Sheet 5 Fig.1-1. Fig.5.

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Patented Sept. 18, 1945 TUNNELING METHOD Frederick Percival Ayers, Barnstaple, North Devon, England Application November 22, 1944, Serial No. 564,695 In Great Britain February 22, 1943 12 Claims. (01. 61-44) This inventionhas reference to a method of and means for tunneling, and has for its object to utilise the tunnel lining'as the foundation of a helical track on which a travelling cutter-supporting frame, rotatable about the axis of the bore, can be mounted and driven to run around the track, advancing as on a screw-thread gradually and continuously as the cutter or cutters carried thereby skives out the earth, rock or the like. The track is progressively extended into the bore as the cutting proceeds.

Briefiy, according'to the invention, the method of tunnelin consists of starting a boring, lining it as far as possible with a lining having a helical track on its inner face, mounting a travelling cutter-support frame to run on said track to carry a rotary cutter extending in advance thereof, rotating said frame to run around said track screwwise thereby advancing its rotary cutter into the working face, and continuing the lining in the Wake of the cutter and in advance'of the travelling cutter-support frame to extend the helical track as the boring proceeds.

In carrying out suchla method two main ways of laying the tunnel lining, and consequently the helical track, may be adopted. In one the lining is constructed of pre-formed sections, and the rotary frame is located sufficiently in rear of the cutter to enable fresh liner sections to be placed in position in advance of the frame and thus to afford a fresh length of helical track to receive the advancing frame as the work progresses. In another way of laying the lining, the lining is formed and shaped in situ as a layer or skin helically formed trailwise in the wake of the cutter head and again in advance of the travel-' lingcutter-supporting frame, the helical track being formed thereon as the lining is being moulded in place. Methods of carrying out this alternative method of laying the lining are set Figure 2 is a diagram of the same cutter-sup porting frame as viewed from the right of Figure 1; .j

Figure 3 shows the lower part of the lined tunnel in section, the plane of the'sectionbeing slightly distorted from a plane normal to the tunnel axis so as, conveniently, to cut through a helical run of the liner sections;

- Figure 4 is a diagram referred to later in this specification in connection with the liner sec Figure 5 is an edge view of a liner section; Figure 6 is a plan of the top edge of the section seen in Figure 5;

Figure 7 is a face view of the concave or interior' side of the liner section shown in Figure 5 but depicted as a flat development thereof; Figure 81s a section on a-a of Figure 7; Figure 9 is a section on b--b of Figure 7;

Figure 10 is a diagram in outline only, also in 'fiat development, ofsome liner sections, as they appear when interfitted in position;

Figures 11 to 14 are views of a shield for use at the working'face described later in this specification, Figure 11 being an elevation showing the interior, Figure 12 being a similar view but of the exterior or. reverse face, Figure 13 a section on c--c of Figure 11, and Figure 14 a side view looking from the left of Figure 11.

Dealing first with the employment of preformed sections, the tunnel lining comprises. interfitting sections each formed with a length of track so disposed on the section that the helical track isbuilt up around the inner face of the lining aslthe sections are progressively laid in o,the wake of the excavation. Referring mainly to Figures 47'10, the sections I may be cast in arcuate lengths, for example in iron, cement or concrete, with an outer plain or other suitable convex surface and. .an interior shallowly recessed and rimmed concave surface, the abutting rims 2 of adjacent sections serving as a convenient means for joining up the lining as depicted in Figures 1 and 3. The outer convex surface may be formed with grooves, pockets, scorings or the like as also may the outer faces of the abutting rims, and by the provision of holes (not shown) extending through the section from the inner surface, cementor otherrequisite material may be injected to the grooves or the like for waterproofing or other purposes.

The sections are advantageously longer in the circumferential direction than in width (i. e. in the height as viewed in Figure 7 than laterally), and throughout this length or height the track portion is formed, conveniently in the middle or otherwise (e. g.along.an edge) as may be found most suitable. This may be in the form of a groove or a grooved rib to take a roller or wheel or its flange, or (as illustrated) in the form of an upstanding V-section or other shaped rail 3 to take a grooved or flanged wheel. At the abutting ends of adjoining sections where the track passes from one section to the other the marginal rim 2 of the section is interrupted if necessary so as not to interfere with the continuity of the track thus built up, as seen at 4 in Figures 6 and 8.

The liner sections are, of course, of arcuate curvature as seen in Figures 3 and 5, and for convenience of producing the helical track, may be given any suitable shape when regarded facially as a flat development. In one example, this shape is rhomboidal a in Figure 4, which will result in the circumferential joints as the long edges 5 winding helically at a pitch determined by the width of the section and the rhomboidal angles. The joints at the abutting ends 6, where the track passes from one to the other are or could be, in this case, parallel to the axis of the bore. In another form (not shown) a plain rectangular shape is used, and in this instance the abutting short edges comparable to the edges 6 of Figure 4 would be .angularly disposed in relation tothe axis of the boreto attain the helical progression of the liner convolutions.

In yet another form, and this is the form illustrated in Figures 5 to 10, the facial shape is substantially rectangular and the progressive spiral feed forward of the sections brought about by forming short lips or other projections l Z-wise on the long sides. That :is to say the ends of the section are wider than the middle or body .part (by reason of the outstanding lip 1 extending :partly along .each side from opposite ends. These square-angled sections would register exactly at their abutting ends as seen in Figure 10, interfitting at their sides, and by reason of. the aforesaid special shape the circumferential runs would gradually creep spirally out of a plane .normal to the axis of the bore. The track length 3 on each section would be slightly inclined to the sides as. shown in Figure 7 to produce the-continuousshelimately the case of Figure 5 it will be clear that.

exactly seven and a half lengths will complete one run, and thus the eighth section to be laid will overlap the beginning of the preceding run :by half a sections length.

These liner sections with their composite helical track 3, when laid, accommodate a travelling cutter-supporting frame which in principle is screwed into the working as the boring proceeds.

Any suitable form of travelling cutter-supporting frame and means for driving it can be used according to the new method of the invention which, as willhave been gathered, consists briefly of starting a boring, lining it as far as possible either by casting in situ orwith sections preformed (as in the example just described) which form a helical track, mounting a travelling cutter-support frame to run on said track by imparting a rotary drive thereto within the boring, cutting away the earth, rock or the like by a rotary cutter or cutters carried by :and extending forward of the frame, and fitting-further liner sections or casting a further length of liner in advance of the frame to extend the helical track as the tunneling progresses. The liner sections remain in situ as the permanent tunnel lining, the recessed concavities lending themselves readily to the attachment of any desired finishing skin. The flat base or ground of the tunnel may be constituted as shown in Figure 3 by flat precast sections 8, bridging from side to side chordwise, engaging convenient rims 2 of the liner sections and supported intermediately by feet members 9 grooved or otherwise recessed at their lower extremities to take over other liner rims 2.

Referring to Figures 1 and 2, in one form of travelling cutter-supporting frame and associated apparatus, by way of example, the frame is carried by a three-point roller engagement I0 with the helical track 3. This three-point may be doubled (as seen in Figure 1), trebled or otherwise multiplied lengthwise of the bore toengage more than one track 3. The three points are not necessarily equi-angularly spaced from the tunnel centre, but preferably spaced to give as much clearance as possible at one part (such as shown uppermost in Figure 2) for the passage of liner sections, workmen, cutter replacements and the like. With this end in view the framework comprises a main frame member ll parallel to the tunnel diameter and slightly oil centre in. one direction so as to divide the tunnel transversely into large and small segments. The small segment is left substantially clear and the large one contains the remainder of the travelling framework. The said main frame member terminates at each end in arunner device l0 engaging the helical track, e. g. a shoe or carriage, pivoted to the frame and having a pair of wheels mounted thereon. Another foundation frame member 12 extends substantially at right-angles from the frame -I I just described, across the large segmental space, is also off centre, :and similarly terminates in a runner device H) engaging the helical track. Other framework I4 is built around the main structural members H and I2.

The said cutter-supporting frame may be driven around its liner track by any suitable means. For example :a central supporting shaft IE3 maybe introduced for the purposeinter aliaof driving or co-operating with driving :means. In the case illustrated, for instance, the frame It l--'l. 2 rotates around a stationary supporting shaft 13 supported axially in the tunnel, by means of a suitable bearing I5 forming part of the rotary framework previously described. The shaft is carried, at some distance rearwardly, away from the travelling framework and the working face, in a supporting framework [6 temporarily riixed or rendered immobile in 'thetunnel. Thelhear ing at this end, or the said fixed supporting framework itself, is so arranged that thesnafit may be axially inclined within limits to take account of bends and deviations from the :axial direction. The shaft may be made tubular for various reasons, particularly when it "is desired to use "a centrally operating pilot boring .head 1.60, which could then be mounted inand driven through the shaft.

The means for turning the travelling frame may comprise a worm J1 and Worm-wheel 18 gearing between the shaft and frame, the power being either manual or derived from an electric motor I9 or other power unit mounted "on the frame, thus in this latter case rendering the travelling frame self-propelling.

The cutter consists of any suitable cutter head 20 having its driving shaft extending {from "the travelling frame, in driven by a second electric motor 2|. or equivalent mounted on the frame. The centre of the cutter is offset from the tunnel centre, and in action it rotates on its owncentre whilst at the same time advancing bodily both circumferentially around the tunnel and forwardly into the working face. This bodily movement is brought about by the helical forward travel of the cutter-supporting frame.

In another method of supporting and operating the travelling cutter-supporting .frame (not shown), the central shaft l3.is rotatable and provides the drive for thehelically travelling oper ation. In this case the rear end of the shaft is brought through suitable bearings in a rear temporarily fixed supporting frame and driven in any way found convenient. The shaft is keyed or otherwise fixedly mounted through the travelling cutter-supporting frame so as to turn the same around its helical liner track.

At the driven end of the shaft provision is made in the fixed supporting frame for inclinations of the shaft from its original tunnel axis as in the previous case. For example the rear bearing block carrying the shaft may be slidably mounted in the centre of the fixed supporting framework in such a Way as to be adiustably movable intwo directions diametrically of the tunnel and at right-angles to one another.

When a central shaft is used, eitherdriven or fixed, there is a spider 22 mounted on thefsame in rear of the fixed supporting frame, the radial legs of which take between respective pairs of cheeks 23 extending rearwardly from the fixed supporting frame There is a clearance to permit the inclination adjustment previously referred to Whilst the length of the cheeks is sufficient to enable the spider arms to slide therein length'ways of the bore. By this means the forward feed of the shaft in relation to the fixed supporting frame I 6 is allowed for.

This latter supporting frame 16 may be clamped in position by jacks 24 forced hard against the lining, and through the medium of which, also, the centering of shaft l3 may be adjusted according as the axis of boring is inclined or not.

Suitable bulkhead arrangements or shields may be employed in conjunction with both the working face and in rear of the rear shaft supporting arrangements.

In the first instance, referring to Figures 11 to 14, a bulkhead plate or shield 25 would be shaped to fit closely to the face being worked, and would naturally be of a snail shape to accommodate itself to the path already skived out. An aperture is formed in the plating through which the cutter extends. In the example the cutting head is housed in a tubular casing 25 extending from the plating 25 and this casing is inclined to correspond with the slight inclination given to the axis of the head. The cutter attacks the face peripherally at the space 21 as well as forwardly and axially at 28, the supporting frame rotating in a clockwise direction with respect to Figure 11. The plating 25 terminates at its out-side periphery in a flange 29 lying parallel to the circumferential wall of the tunnel. The whole shield would be carried by and rotate with the cutter-supporting frame. The lining may be carried up to and interiorly overlap the said lip of the shield as in Figure 1 where the shield is indicated by broken lines, and in this case, if necessary, a suitable configuration may be applied to the liner sections to facilitate such an overlap. For example, a step may be formed on the outer face of the section to allow the bulkhead lip to worlgbetween the liner and the soil. The. excavated soilcould be brought ,awayby meansof a chute or other convenient duct leading from the tubular part 26.

Referringnow-to the case where the lining is shaped in situ, the shield carrying the cutter may be used to accommodate a roll of sheet metal rotatably mounted thereon with its axis parallel to that of the tunnel so that it would unwind and lie against thecircumferential wall of the boring directly behind the cutting head and its shield.

As the latter rotates and :advances, the sheet slidably mounted on the shaft 3 to facilitate plac sheet of expanded metal, strong wire netting .or

other suitable reinforcement for a cementitious lining. In this case a cement lining could be .pressed against the reinforcement as the boring proceeded, and in effect a concrete lining would be cast along the tunneling as the cutter-head moved forward. A quick-drying cement would be necessary, and the interior face would be generally fiat with tracks, raised or recessed, formed for taking the travellingcutter-supporting frame. An elevating device 30 may be rotatably and ing the linen'sections in position. For example an arm 3| on the device 30 can be disposed to project forwardly and terminate in any convenient gripper or carrying bracket 32. This latter can be loaded when it is in a conveniently low po- 4Qsition in rear of the travelling cutter-supporting framework, and then the device manipulated to carry the section to the requisite position.

I claim:

1. A method of tunneling which consists of starting a boring, lining it as far as possible with a lining having a helical track on its inner face, mountin a travelling cutter-support frame to run on said track to carry a rotary cutter extending in advance thereof, rotating said frame to run around said track screw-wise thereby advancing its rotary cutter into the working face, and continuing the lining in the wake of the cutter and in advance of the travelling cuttersupport frame to extend the helical track as the boring proceeds.

2. A method of tunneling according to claim 1 in which the lining is carried out by laying preformed interfitting liner sections each constructed with a length of track so disposed in or on the section that the helical track is built up around the inner face of the lining as the sections are progressively laid in the wake of the excavation.

3. A method of tunneling according to claim 1 characterised by the employment of liner sections which, regarded facially as a fiat development are substantially rectangular with a short lip on each of the long sides at opposite ends 4. A method of tunneling according to claim 1 in which the travelling cutter-support frame is advanced screw-wise along the tunnel guided by a central longitudinal shaft mounted in the boring,

5. A method of tunneling according to claim 1 in which the cutting head carried by the travelling frame is rotated on its own axis, and also turns with the helical movement of the frame on which it is mounted, and is driven by a power unit carried by the frame.

6. In a method of tunneling according to claim 1 the employment, of a bulkhead or shield against the working face, said shield being secured to the travelling frame, and rotating and helically advancing therewith,

'7. A method of tunneling which consists of starting a boring, lining it as far as'possible with a lining having a helical track on its inner face, mountin a traveling cutter-support frame to run on said track to carry a rotary cutter-extending in advance thereof, rotating said frame to run around said track screw-wise, thereby advancing its rotary cutter into the working face, continuing the lining in the wake of the cutter and in advance of the traveling cutter-support frame to extend the helical track as the boring proceeds, such lining being carried out by laying precast arcuate interfitting liner sections having an outer plane or other suitable convex surface and an interiorly shallowly recessed and rimmed concave surface formed with part of the helical track, and arranging the rims of ad- Jacent sections in abutting relationship and serving to join the liner sections together.

8. A method of tunneling according to claim '7 in which the track part is in the form of a'rim extending from one end of the liner section to the other forming a track on which runs a roller, wheel or equivalent of the rotary cutter support frame.

.9. A method of tunneling according to claim 7 characterized by the employment of liner sections, which, regarded facially a a fiat development, are rhomboidal in shape.

10. A method of tunneling which consists of starting a boring, lining it as far as possible with a lining having a helical track on its inner face, mounting a traveling cutter-support frame to run on said track to carry a rotary cutter extending in advance thereof, rotating said frame to run around said track screw-wise along the tunnel guide by a central longitudinal shaft mounted in the boring, thereby advancing it rotary cutter into the working face, continuing the lining in the wake of the cutter and in advance of the traveling cutter-support fram to extend the helical track as the borin proceeds and holding said shaft against rotation while revolving the traveling frame there around through the medium of suitable gearing and a source of power. 11. A method of tunneling according to claim 10 in which the traveling frame carries its own source of power, such as an electric motor, and drives on to the shaft via a worm gear so as to secure its rotation and thus its helical advancement in the direction of the working face.

I 12. In a method of tunneling, according to claim 10, mounting the central shaft in a rear framework adapted to be secured temporarily in the tunnel, and advancing the said framework step by step along the tunnel in the direction of the working face as and when the forward feed of the central shaft necessitates.

FREDERICK vPERCIVAL AYERS.

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