Improvements in or relating to joining concrete elements

Abstract

 The disclosure relates to a concrete element (10) having a corner (14) between a side face (12) and an end face (11) in which a box shaped cavity (15) is formed. A pair of U-shaped loops (18) is cast in the segment at the corner with base members (19) of the loops extending parallel to one another across the cavity to receive a fixing bolt (12) which has a head (21) and washer brackets (22) engaging behind the loops and a shank extending from the end of the element to engage in a nut similarly held in a recess of a corresponding segment for securing the segment ends together.
The arrangement permits the bolt to be tightened through the cavities at the sides of the segments.
The arrangement is particularly suitable for securing arcuate concrete tunnel lining segments together.

Description

[0001] This invention relates to concrete elements as is particularly although not exclusively applicable to concrete elements in the form of precast arcuate concrete tunnel or shaft lining segments.

[0002] This invention provides a concrete element having a corner between a pair of mutually angled edge faces joint to an adjacent element, the corner having an anchorage cast into the element at or adjacent one of said edge faces of said corner with a cavity formed behind the anchorage which is open to the other side edge of the corner to enable an attachment member to be inserted through the cavity and engaged with the anchorage to be held thereby and project from said one side edge of the corner to engage with another element.

[0003] More particularly the anchorage may provide an opening through which the attachment member extends, the attachment member having abutment means to engage behind the anchorage to retain the attachment member in the anchorage.

[0004] In one embodiment of the invention the anchorage may comprise a plurality of bars cast into the concrete element and spaced apart to permit the attachment member to extend through the bars with the abutment means of the attachment member engaged behind the bars.

[0005] More particularly the bars may comprise a pair of parallel bars cast into the concrete element.

[0006] Furthermore the bars may be formed by the bases of rigid U-shaped elements extending from said one edge face of the element into the element.

[0007] Alternatively, reinforcing members may be cast in the element and said bars may be connected to the reinforcing members.

[0008] In any of the above arrangements the bars may be cast in the concrete element immediately adjacent said one end face and the cavity in the concrete element may extend across the corner of the element between said respective edge faces.

[0009] In an alternative construction the bars may be cast in the element at a location spaced behind said one edge face of the element, a throughway being formed between the bars and said one edge face through which the attachment member extends and the cavity extending from the other edge face into the concrete behind the bars.

[0010] In a further construction the anchorage may comprise an apertured plate cast into the concrete element at or adjacent said one edge face.

[0011] In the latter construction the element may contain reinforcing members cast into the element and to which the anchorage plate is connected.

[0012] The invention also provides a concrete element according to any of the above arrangements in the form of a pre-cast arcuate concrete tunnel or shaft lining segment having corner joints at each corner thereof for connecting the axially extending edges of adjacent segments together.

[0013] The segment may have passages formed between the cavities and the outer convex surface thereof through which grout pumped into the gap between the outer surface of a segment after erection may pass to fill the cavities.

[0014] 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 side view of a joint between two arcuate concrete tunnel lining segments;

Figure 2 is a view on the section A-A on Figure 1;

Figure 3 is a perspective view of a corner of one of the segments of Figure 1;

Figures 4 and 5 are similar views to Figures 1 and 2 showing a modified construction;

Figures 6 and 7 are also similar views to Figures 1 and 2 showing a further modified construction; and

Figures 8 and 9 are also similar views to Figures 1 and 2 showing a still further modified construction.

[0015] Referring firstly to Figures 1 to 3 of the drawings, there is shown parts of two pre-cast concrete arcuate tunnel lining segments 10 having axially extending end faces 11 and circumferentially extending side faces 12. The segments are secured together at their axially extending edge faces with a gasket 13 between the adjacent faces by means of corner connections which will now be described with particular reference to Figure 3.

[0016] Figure 3 of the drawing shows one corner indicated generally at 14 of one of the segments 10 between a side face 12 and an end face 11. At a mid-position within the thickness of the segment, the corner is formed with a box shaped cavity 15 which extends across the corner and is open at 16 to the side face 12 and at 17 to the end face 11. A pair of fla bottomed U-shaped loops 18 are cast into the segment at the corner with the base members 19 of the loops extending parallel to one another and adjacent to the end face 17. The base members extend parallel to one another across the cavity 15 as shown in Figure 3 and the arms of the U-shaped members extend into the thickness of the segment as illustrated in Figure 1 and made be tied into main reinforcement bars (not shown) of the segment. A fixing bolt 20 extends through the exposed parts of the loops 19 and is held captive by a head 21 and washer 22 on the bolt engaging behind the loops within the cavity 15. The cavity 15 extends sufficiently behind the loops 19 to enable the bolt 20 to be inserted through the loops from the opening 16 in the side face of the segment into the cavity.

[0017] The corresponding corner of the adjacent segment has a similar cavity and loop arrangement and the fixing bolt 20 extends through the loops 19 of the further corner to receive a washer 23 and nut 24 for securing the end faces of the segments together. A similar connection is provide between the corner joints at the opposite ends of the end faces 17 so that the end faces of the segments can be secured together adjacent both ends thereof. In erecting a ring of segments in a tunnel or shaft, two segments are located with their axially extending faces in abutment and with the segments spaced from the previously erected ring of segments. The end faces of the segments can then be secured together as described above and once a complete ring of segments has been secured together in a similar manner, the ring is then moved into engagement with and secured to the previously erected ring. The segments of one ring may for example, be connected to the segments of the previously erected ring using any of the arrangements disclosed in our U.K. Patent Specification Nos. 2003212, 2139277, 2139268, 2139278 or 2133852. A further ring of segments is then erected and secured together as before.

[0018] A throughway 25 is provided between each cavity 15 and the outer circumferential surface of each segment so that when the lining has be fully erected and grout is delivered under pressure to fill the cavity between the outer surface of the lining and the excavated tunnel, the grout will be driven into the cavities 15 through the throughways to fill and seal the cavities. Thus the connecting elements including the bolts and bars are protected against corrosion.

[0019] Figures 4 and 5 show a similar arrangement to that of Figures 1 and 2 and like parts have been allotted the same reference numerals. The main difference is that the loops 18 are cast in the segments 10 with the base parts 19 of the loop set back from the respective end faces 11 thus there is a wall concrete 26 between each cavity 15 and the end face 11 which is formed with a bore 27 through which the bolt 20 extends. The arrangement is otherwise similar to that described above.

[0020] Figures 6 and 7 show a further variation on the arrangement of Figures 1 and 2 in which the corner one of the segments 10 is formed as described with respect to Figures 1 and 2 and the adjacent corner of the other segment 10a has a threaded cast-in socket 28 extending into the segment from the end face 11 to receive the bolt 20 projecting from said one segment. The cast in socket 28 is attached to the reinforcement 29 of said other segment. As can be seen in Figure 7, the joints at opposite ends of the segments are handed so that each segment has a bolt projecting from one corner and a socket at the other corner for engagement with a corresponding socket and bolt respectively of an adjacent segment.

[0021] The arrangement shown in Figures 8 and 9 is also similar to that of Figures 1 and 2 except that the loops 18/19 are replaced by apertured plates 30 cast into the end faces of the segments to which loops 31 are connected which extends into the respective segments and may be connected to main reinforcement bars. The arrangement is otherwise similar to that described above.

Claims

1. A concrete element having a corner between a pair of mutually angled edge faces joint to an adjacent element, the corner having an anchorage cast into the element at or adjacent one of said edge faces of said corner with a cavity formed behind the anchorage which is open to the other side edge of the corner to enable an attachment member to be inserted through the cavity and engaged with the anchorage to be held thereby and project from said one side edge of the corner to engage with another element.

2. A concrete element as claimed in Claim 1, wherein the anchorage provides an opening through which the attachment member extends, the attachment member having abutment means to engage behind the anchorage to retain the attachment member in the anchorage.

3. A concrete element as claimed in Claim 2, wherein the anchorage comprises a plurality of bars cast into the concrete element and spaced apart to permit the attachment member to extend through the bars with the abutment means of the attachment member engaged behind the bars.

4. A concrete element as claimed in Cliam 3, wherein the bars comprise a pair of parallel bars cast into the concrete element.

5. A concrete element as claimed in any of Claims 2 to 4, wherein the bars are formed by the bases of rigid U-shaped elements extending from said one edge face of the element into the element.

6. A concrete element as claimed in any of Claims 2 to 5, wherein reinforcing members are cast in the element and said bars are connected to the reinforcing memebers.

7. A concrete element as claimed in any of the preceding claims, wherein the bars are cast in the concrete element immediately adjacent said one end face and the cavity in the concrete element extends across the corner of the element between said respective edge faces.

8. A concrete element as claimed in any of Claims 1 to 6, wherein the bars are cast in the element at a locations spaced behind said one edge face of the element, a throughway being formed between the bars and said one edge face through which the attachment member extends and the cavity extending from the other edge face into the concrete behind the bars.

9. A concrete element as claimed in Claim 1, wherein the anchorage comprises an apertured plate cast into the concrete element at or adjacent said one edge face.

10. A concrete element as claimed in Claim 8, wherein the element contains reinforcing members cast into the element and to which the anchorage plate is connected.

11. A concrete element as claimed in any of the preceding claims in the form of a pre-cast arcuate concrete tunnel or shaft lining segment having corner joints as claimed in any of the preceding claims for connecting the axially extending edges of adjacent segments together.

12. A concrete segment as claimed in Claim 11, wherein each corner of the segment has said corner joints for connecting with adjacent corners of further segments to form a ring of interconnected segments.

13. A concrete segment as claimed in Claim 11, wherein each axially extending edge has one of said anchorages at one corner thereof with a bolt projecting therefrom to engage in a corner of an adjacent segment and is cast in screw-threaded socket in the other corner of the segment to receive a projecting bolt from said adjacent segment.

14. A concrete segment as claimed in Claim 11, wherein passages are formed in the concrete element between the cavities and the outer convex surface of the segment through which grout pumped into the gap between the outer surface of a segment after erection may pass to fill the cavities.

Drawing