GB2100772A - Improvements in or relating to arcuate lining segments for shafts or tunnels - Google Patents

Abstract

The disclosure relates to a shaft lining comprising precast concrete arcuate segments (11) having upper and lower circumferentially extending end faces (22, 23) between which two parallel through holes (24) extend at spaced locations opening into recesses (25) at the bottom face and containing bolts (26) supported in and extending up through the holes. Screw threaded sockets (31) are formed in the lower end faces of each segment off-set from the recesses to receive the bolts from the segment below to enable a ring of segments to be secured beneath a previously erected ring of segments in the shaft lining as the shaft is driven downwardly with the segments appropriately staggered around the lining with respect to the segments above. A tunnel lining similarly constructed is also disclosed. <IMAGE>

Description

SPECIFICATION Improvements in or relating to arcuate lining segments for shafts or tunnels This invention relates to arcuate lining segments for shafts or tunnels.

The invention provides an arcuate lining segment for a shaft or tunnel having circumferentially extending end faces to receive adjacent segments on either side thereof, at least two means for attachment of the segment to an adjacent segment extending from one of said end faces through the segment and projecting from the other end to engage an adjacent segment and, in said one end face, at least two attachment receiving means located respectively adjacent the two attachment means and off-set therefrom by the same distance to receive and hold the attachment means on an adjacent segment to secure that segment to the first mentioned segment in staggered relation according to the off-set between the respective attachment means and receiving means.

Preferably each attachment means comprises a through bolt having a head located in a recess in said one end of the segment and a screw threaded shank projecting from the other end of the segment and each attachment receiving means comprises a screw threaded socket.

The invention also provides a tunnel or shaft lining comprising a plurality of rings of segments according to any of the above arrangements located end-to-end along the shaft or tunnel.

In one specific arrangement, one segment in each ring of segments is formed with a frustospiral groove extending across the inner face from one circumferential end to the other and the stagger between the segments of adjacent rings is such that a continuous spiral groove winding around the lining is formed by the frusto-spiral grooves in each ring.

The following is a description of some specific embodiments of the invention, reference being made to the accompanying drawings in which: Figure 1 is a cross-sectional view through a shaft lining; Figure 2 is a section on the line 2-2 of Figure 1; Figures 3 and 4 show details of joints in the lining; Figures 5 and 6 are plan views of two specific segments of the lining; Figure 7 is a detailed view of the attachment between vertically adjacent segments of the lining; Figure 8 is a sectional view through a tunnel lining and showing one ring of the lining; Figure 9 is a section on the line 9-9 of Figure 8; Figure 10 is a detailed view showing the attachment between a segment of one ring and a segment in an adjacent ring; and Figure 11 is a further detailed view of the segment part shown in Figure 10.

Reference will be made first to the shaft lining illustrated in Figures 1 to 7.

Referring firstly to Figure 1 of the drawings, there is shown a ring 10 of pre-cast arcuate concrete segments comprising ten uniform thickness segments 1 a pair of increased thickness segments 1 2a and 1 2b forming a spiral unit which will be described in greater detail below, two wedge segments 1 3 which merge the spiral unit segments with the remaining segments and which reduce in thickness from that of the spiral segments to the remaining segments; and finally a short key segment 14 located in the ring diametrically opposite the segments of the spiral unit.

The pair of segments making up the spiral unit are formed on the inner sides 1 5 thereof with a frusto-spiral groove 1 6 leading downwardly across the surface of the segments from the upper circumferential end of one segment 1 2a to the lower circumferential end of the other segment 12b.

The spiral unit 1 2a, 1 2b, is advanced around the axis of the shaft by an appropriate amount for each succeeding ring of the lining so that the frusto-spiral 16 of the successive spiral units down the lining form a smooth spiral groove winding around the inner surface of the lining from the top to the bottom of the shaft. The extent of the advance of the spiral unit of the lining below the lining illustrated in Figure 1 is indicated at 1 7 of Figure 1. In the embodiment illustrated the spiral is a left-hand turning spiral as viewed from above in Figure 1 but the arrangement would be equally applicable to a right-hand turning spiral. The spiral groove 1 6 forms a feed groove around which the granular material such as coal can be fed into the shaft to fill up the shaft.The spiral angle is determined in relation to the radius of the lining so that the coal tends to roll down the spiral groove staying within the confines of the groove. The spiral thus provides a means for filling up the shaft whilst avoiding the free fall of the material. The spiral also enables material to be drawn off from the bottom of the shaft when emptying the shaft.

Such systems are particularly suitable for forming temporary storage of coal in coal mines.

The adjacent lining segments 11, 12, 1 3 around the ring are secured together by a pin and hoop arrangement which forms the subject of our U.K. Patent Application No. 31169/78 to which reference should be made for the detailed description. Figure 3 illustrates a typical joint between two lining segments and it will be seen that part cylindrical cavity 1 8 extends into the end of each segment from the inner side thereof and a pair of tensile hoops 19 project from one segment into the cavity and a single hoop 20 projects from the other segment into the cavity between the hoops 19. A pin not shown is driven through the overlapping hoops to hold the segments together.

Two such joints are formed between each adjacent pair of segment ends.

Figure 4 shows a similar joint between the segment 11 and the key segment 14.

The system of securing together the segments of adjacent rings in order to achieve the appropriate stagger for the spiral groove will now be described. Firstly it must be mentioned that the shaft is excavated from the top downwards and the rings of the lining segments are erected in the shaft as excavation progresses.

Referring now to Figure 5 and 7 of the drawings, the segment 11 illustrated has upper and lower circumferentially extending end faces 22, 23 between which two parallel through holes 24 extend at spaced locations around the segment. The through holes 24 opens into a recess 25 at the bottom face 23 of the segment.

The through holes contain long bolts 26 extending up through the bores. Each bolt has a head 27 at its lower end located in the recess 25 which bears against a washer 28 at the bottom of the recess 25. The diameter of the shank of the bolt is somewhat less than the diameter of the through hole 24 so that there is significant clearance between the bolt and the hole to permit lateral movement of the bolt in the hole. Mid-way up the shank 29 there is an encircling collar 29a on the shank which engages the bore 24 and forms a pivot point about which the bolt can be rocked in the bore 24 when lining up with a socket as described below. The upper end of the bolt shank is screw-threaded as indicated at 29 and projects from the upper face 22 of the segment.Spaced to one side of the recess 25 of the bolt hole 23 in the bottom face of each segment there is cast-in internally screw-threaded socket 31 to receive the screw-threaded end 29 of the bolt from the segment below as can be seen in Figure 7. The sockets 31 are spaced from the respective bolt holes 24 by an equal off-set so that in relation to each segment, both the segment above and the segment below will be staggered around the axis of the shaft for the purpose described earlier. The detailed arrangement of the screw threaded socket 31 is best seen in Figure 7. It will be seen that there is a tapered entry 32 formed in the end face of the segment leading into the socket 31 and above the socket there is a plate 33 through which reinforcement 34 for the segment extends.

As indicated previously, the shaft lining is erected by excavating the shaft downwardly and, as the excavation proceeds, the new rings of linings are erected below the previously erected ring. Thus when a new ring of linings is to be laid, the lining segments are offered up underneath the previously erected ring with the bolt 29 in line with the sockets 31 facing downwardly from the undersides of the segments of the previously erected ring. The bolts 24 are pushed upwardly and rocked laterally until the screw threaded shanks 29 line up with and enter the sockets 31.

The bolts are then screwed up until tight to hold the new lining to the lining above.

Figure 5 of the drawing illustrates in degrees the lay out of sockets and bolt holes required to achieve the necessary stagger between adjacent ring of segments for lining up the helical groove 1 6. The upper face 29 of each segment is also provided with two spaced lifting sockets 36 for receiving lifting eyes from which the segment can be suspended from a hoist for transporting the segment and lowering the segment into the shaft ready for erection as required.

Figure 6 of the drawings shows the wedge segment with the positions of the bolts holes 24 and socket 31 as with the normal lining 11. The lifting socket 36 adjacent the thicker end of the segment is however displaced in the radius along which the bolt holes and sockets 33 lie and the socket lies generally in the centre of the face so that the segment is approximately balanced for lifting.

Figures 8 to 11 show a tunnel lining in which a similar circumferential joint system is used to provide stagger between adjacent rings of segments and like part have been allotted the same reference numerals. Figure 8 shows one ring of the segments which are all generally similar to the uniform thickess segment 11 of the previously described embodiment and the key segment 14 is located at the top of the ring. The adjacent segments in each ring are secured together by the over-lapping hoop and pin construction described in our U.K.Patent Application No. 31169/78. The sockets 33 in the end faces of the segments to receive the threaded shank 29 of the bolts projecting from the adjacent segments are slightly different and comprise a tubular metal sleeve 40 cast into the segment end with a flanged nut 41 at the end of the sleeve and to which the screw threaded shank 29 engages. A further feature of the arrangement is the provision of a malleable iron eye and grout socket 42 midway across the segment adjacent bolt hole 26 and intersecting the bolt hole so that grout injected through the socket also fills up the gap between the bolt and bolt hole. The arrangement is otherwise similar to that of the shaft lining described above except that the rings of segments are laid horizontally as the tunnel is excavated and the lining is built up so that the key of every other ring is rolled alternately one pitch left or right of the centre-line.

Claims (12)

1. An arcuate lining segment for a shaft or tunnel having circumferentially extending end faces to receive adjacent segments on either side thereof, at least two means for attachment of the segment to an adjacent segment extending from one of said end faces through the segment and projecting from the other end to engage an adjacent segment and, in said one end face, at least two attachment receiving means located respectively adjacent the two attachment means and off-set therefrom by the same distance to receive and hold the attachment means on an adjacent segment to secure that segment to the first mentioned segment in staggered relation according to the off-set between the respective attachment means and receiving means.

2. A segment as claimed in claim 1 wherein each attachment means comprises a through bolt having a head located in a recess in said one end of the segment and a screw threaded shank projecting from the other end of the segment and each attachment receiving means comprises a screw threaded socket.

3. A segment as claimed in claim 2 wherein the bolts extend with clearance through holes formed in the segment to permit lateral adjustment of the bolts for engagement in the receiving means of an adjacent segment.

4. A segment as claimed in claim 3 wherein partway along each both there is a collar engaged in the bolt hole to support the bolt in the hole whilst permitting pivotal adjustment of the bolt in the collar.

5. A segment as claimed in any of the preceding claims wherein each receiving means comprises a blind hole formed in the segment having a sleeve fixed therein with a nut to receive the bolt at the end of the sleeve adjacent the blind eye of the hole.

6. A segment as claimed in any of the preceding claims wherein for each through hole in the segment accommodating a bblt a grout hole is formed in the segment extending through the segment and intersecting the bolt hole so that grout ejected through the hole also fills up the bolt hole around the bolt.

7. A tunnel or shaft lining comprising plurality of rings of segments according to any of the preceding claims located end-to-end along the shaft or tunnel.

8. A shaft lining as claimed in claim 7 wherein one segment in each ring of segments is formed with a frusto-spiral groove extending across the inner face from one circumferential end to the other and the stagger between the segments of adjacent rings is such that a continuous spiral groove winding around the lining is formed by the frusto-spiral grooves in each ring.

9. A shaft lining as claimed in claim 9 wherein the frusto-spiral groove is formed across a pair of adjacent segments.

10. A shaft lining as claimed in claim 9 wherein each lining ring is made up of a number of similar segments of uniform thickness, one or more segments of increased thickness and provided with the frusto-spiral groove extending across the inner surface thereof and two merging segments each increasing from said uniform thickness at one end to the thickness of the spiral segment or segments at the other end to merge the spiral segment or segments with the rest of the lining.

11. A shaft lining substantialjy as described with reference to and as illustrated in Figures 1 to 7 of the accompanying drawings.

12. A tunnel lining substantially as described with reference to and as illustrated in Figures 8 to 12 of the accompanying drawings.