Abstract
A tunnel segment gasket and a method for making and using a tunnel segment gasket (1, 1) comprising a shaped profile (3, 3) having at least two anchoring legs (5, 5) for casting in to a tunnel segment (6, 6); a plurality of longitudinally extending bores (7, 7); a shot film joint (43) and a strengthening element (11, 4) at the base (9) of the gasket (1, 1).
Claims
1. A tunnel segment gasket comprising: a shaped profile having at least two anchoring legs for casting in to a tunnel segment; a plurality of longitudinally extending bores; a shot film joint (43) and a strengthening element at a base of the tunnel segment gasket.
2. The tunnel segment gasket according to claim 1, wherein the strengthening element is a rhombus shape having a centre line parallel to the shot film joint.
3. The tunnel segment gasket according to claim 1, wherein the strengthening element is integral with the shot film joint.
4. The tunnel segment gasket according to claim 3, wherein the shot film joint is concealed within the tunnel segment gasket and the strengthening element is exposed at the base of the tunnel segment gasket.
5. The tunnel segment gasket according to claim 1, wherein the cross-sections of the plurality of longitudinally extending bores are circular or semi-circular.
6. The tunnel segment gasket according to claim 1, wherein the tunnel segment gasket comprises at least two curved protrusions on the base of the tunnel segment gasket.
7. The tunnel segment gasket according to claim 6, wherein the at least two curved protrusion are positioned between the two anchoring legs.
8. The tunnel segment gasket according to claim 1, wherein the tunnel segment gasket further comprises at least two shaped transverse protrusions.
9. A method of forming a tunnel segment gasket joint comprising: extruding a first tunnel segment gasket through a first cutting guide; extruding a second tunnel segment gasket through a second cutting guide; cutting an angled end of both the first and second tunnel segment gaskets; providing a thin elastomeric film between the angled ends of the first and second tunnel segment gaskets to form a joint.
10. The method according to claim 9, further comprising providing a strengthening element integral with the joint.
11. The method according to claim 9, further comprising providing an integral strengthening element wherein the integral strengthening element is exposed at the base of the first tunnel segment gasket.
12. The method according to claim 9, wherein the thin elastomeric film is a rubber film.
13. The method according to claim 9, wherein the thin elastomeric film has a thickness of between about 0.2 mm and about 2 mm.
14. The method according to claim 12, wherein the thin elastomeric or rubber film is provided by injecting the thin elastomeric or rubber film between the angled ends of the first and second tunnel segment gaskets to form a joint.
15. The method according to claim 9, further comprising: clamping at least one end of both the first and second tunnel segment gaskets.
16. A tunnel segment gasket joint produced by a method comprising: extruding a first tunnel segment gasket through a first cutting guide; extruding a second tunnel segment gasket through a second cutting guide; cutting an angled end of both the first and second tunnel segment gaskets; providing a thin elastomeric film between the angled ends of the first and second tunnel segment gaskets to form a joint, wherein the thin elastomeric film is a rubber film that has a thickness of between about 0.2 mm and about 2 mm provided by injecting the thin elastomeric or rubber film between the angled ends of the first and second tunnel segment gaskets to form a joint; providing a strengthening element integral with the joint, wherein the integral strengthening element is exposed at the base of the first tunnel segment gasket; and clamping at least one end of both the first and second tunnel segment gaskets.
Description
[0038] The invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:
[0039] FIG. 1a is a perspective view of a slice through a tunnel segment gasket constructed in accordance with a first embodiment of the present invention;
[0040] FIG. 1b is a cross-sectional view across the joint, effectively showing half of a tunnel segment gasket, as shown in FIG. 1a, in accordance with a first embodiment of the present invention;
[0041] FIG. 2 is a cross-sectional view of a tunnel segment gasket, as shown in FIG. 1b, cast in to a concrete tunnel segment;
[0042] FIG. 3 is a cross-sectional view of a tunnel segment gasket constructed in accordance with a second embodiment of the present invention;
[0043] FIG. 4 is a cross-sectional view of a tunnel segment gasket constructed in accordance with a second embodiment of the present invention shown in FIG. 3, which is shown cast-in to a tunnel segment;
[0044] FIG. 5 is a cross-sectional view of a tunnel segment gasket constructed in accordance with a further embodiment of the present invention;
[0045] FIG. 6 is a cross-sectional view of a tunnel segment gasket constructed in accordance with the further embodiment of the present invention shown in FIG. 5, which is shown cast-in to a tunnel segment;
[0046] FIG. 7 is a view from above of a cutting guide for cutting a first (left hand) tunnel segment gasket of the present invention to be joined to form a corner joint, as described with respect to FIG. 15;
[0047] FIG. 8 is a view from the side of the cutting guide of FIG. 7, for cutting a first tunnel segment gasket of the present invention to be joined to form a corner joint;
[0048] FIG. 9 is a perspective view of the cutting guide of FIGS. 7 and 8 for cutting a first tunnel segment gasket of the present invention to be joined to form a corner joint;
[0049] FIG. 10 is a view from above of a cutting guide for cutting a second (right hand) tunnel segment gasket of the present invention to be joined to form a corner joint, as described with respect to FIG. 15;
[0050] FIG. 11 is a view from the side of the cutting guide of FIG. 10 for cutting a second tunnel segment gasket of the present invention to be joined to form a corner joint;
[0051] FIG. 12 is a perspective view of the cutting guide of FIGS. 10 and 11 for cutting a second tunnel segment gasket of the present invention to be joined to form a corner joint;
[0052] FIG. 13 is a perspective view of the left hand and right hand cutting guides;
[0053] FIG. 14 is a schematic view of the cutting of the left hand and right hand tunnel segment gaskets according to the present invention;
[0054] FIG. 15 is a perspective view of a tunnel segment gasket joint having an obtuse angle, in accordance with the present invention;
[0055] FIG. 16 is a view from above of a tunnel segment gasket joint having an obtuse angle;
[0056] FIG. 17 is an internal view of the tunnel segment gasket joint of FIG. 16;
[0057] FIG. 18 is a perspective view of a tunnel segment joint having an acute angle; and
[0058] FIG. 19 is a perspective view of a tunnel segment gasket joint having an acute angle, according to the present invention.
[0059] Referring to FIG. 1a and FIG. 1b, showing a slice through the tunnel segment gasket (TSG) 1, the TSG 1 comprises an elastomeric (rubber) body 3 having a shaped profile. The body 3 comprises anchoring legs 5, such that the full profile of the gasket 1, as shown in FIG. 2 comprises two anchoring leg 5, with one on each side of the TSG 1. The TSG 1 further comprises a plurality of longitudinally extending bores 7.
[0060] Referring to FIG. 2, each of the anchoring legs 5 secures the TSG 1 in position when cast in to a concrete tunnel segment 6. In use, the gasket 1 is compressed under load of the concrete tunnel segments 6 in which the TSG 1 is cast. The width of the gasket 1, excluding the shoulders 13, in a first embodiment is about 28 mm and the height of the main body of the gasket 1, excluding the anchoring legs 5, is about 18 mm. The height of each shoulder 13 from the base of the gasket 1 is about 9 mm. The width of the base of the gasket is about 21 mm.
[0061] Referring to FIG. 1b, the gasket 1 further comprises a shot film joint 43 and a strengthening element 4 at the base of the gasket 1. It is understood that the base of the gasket refers to the face of the gasket 1 between the two anchoring legs 5, which is external to the shot film joint 43. The strengthening element 4 is shaped and positioned to increase the strength of the tunnel segment gasket 1 at the joint 43 and reduces the risk of crack propagation when the tunnel segment gaskets 1 are joined and cast in to concrete tunnel segments 6.
[0062] In the embodiment of FIG. 1b, the strengthening element 4 has four sides forming a rhombus shape wherein a centre line of the strengthening element 4 is aligned with the centre line of the shot film joint 43. The strengthening element 4 is integrally formed with the shot film joint 43. The shot film joint 43 is concealed within the tunnel segment gasket 1 and the strengthening element 4 is concealed, in use by the concrete tunnel segment 6 into which it is cast. It is understood that, in alternative embodiments of the present invention the strengthening element 4 can have a different shape according to user requirements. The shape of the strengthening element 4 is determined by the method described with respect to FIGS. 15 and 17 and is formed integrally with the shot film joint 43.
[0063] Referring to FIG. 3, the tunnel segment gasket (TSG) 1 comprises an elastomeric (rubber) body 3 having a shaped profile. The profile comprises two anchoring legs 5 and a plurality of longitudinally extending bores 7. The base 9 of the TSG 1 optionally has two curved protrusions 11 that are arranged to increase the surface area of the base 9 of the TSG 1. The embodiment shown in FIG. 1 has a rubber volume for a 1000 mm length of gasket of 302 cc; however, the volume of rubber is given by way of example only. For any given gasket, the volume of rubber is varied according to the requirements of the given gasket; for example depending on the application for which it is to be used. The profile further comprises two shoulders 13 protruding substantially perpendicular to the direction of the anchoring legs 5. The width of the gasket (FIG. 1-A), excluding the shoulders 13, in a first embodiment is about 28 mm and the height of the main body of the gasket (FIG. 1-B), excluding the anchoring legs 5 is about 19 mm. The height of each shoulder 13 from the base of the gasket (FIG. 1-C) is about 8 mm. The width of the base of the gasket (FIG. 1-D) is about 21 mm.
[0064] In use, as shown in FIG. 4, the anchoring legs 5 are cast in to a tunnel segment 13. The longitudinally extending bores 7 of the TSG 1 are shown to have a circular cross-section. However, in alternative embodiments the cross-section of the longitudinally extending bores 7 can be configured according to the anticipated load requirements of the TSG 1. That is, it is understood that the number, shape and dimensions of each of the longitudinally extending bores 7 can vary according to the gasket's load requirements. Referring to FIG. 2, when the TSG 1 is cast into the tunnel segment 23, the volume of the groove 15 in which the TSG 1 sits has a volume of about 335 cc; however, the volume of the groove is given by way of example only. For any given gasket, the volume of rubber is varied according to the requirements of the given gasket; for example depending on the application for which it is to be used. The volume of the rubber and the groove 15 is carefully calculated to ensure that it will be possible to close adjacent tunnel segments 23 securely. The shoulders 13 of the TSG 1 are configured to protrude within the tunnel segment in which they are cast, with the shoulders 13 substantially parallel to and along the upper face of the tunnel segment 23.
[0065] In the embodiments shown in FIG. 3 (and FIG. 4), the optional protrusions 11 have a substantially semi-circular profile extending along the base 9 of the TSG 1. The curved profile of the curved protrusions 11 prevents any points of stress when the TSGs are joined; thus, avoiding the risk of splitting of the joint or crack propagation when a load is applied to the joint; that is, when the TSG 1 is used in joining two tunnel segments (not shown). It is envisaged that the curved profile of the curved protrusions 11 can take the form of an elongate beading running along the length of the underside of the TSG 1. The cross-section of the curved protrusions 11 is semi-circular or domed. It is also envisaged that it alternative embodiments, a plurality of curved protrusions are provided, however, the preferred embodiment is that shown in FIGS. 1a, 1b and 2, as referred to above. By providing the optional curved protrusions 11, the surface area of the base 9 of the TSG 1 is increased to allow for efficient joining of two TSGs 1 without an excess of elastomeric material being required at the joint.
[0066] As shown in FIG. 5 and FIG. 6, in a further embodiment of the present invention, when the TSG 1 is to be cast in to a tunnel segment 23, having groove volume 25 of about 434 cc for a 1000 mm length, the dimensions of the TSG 1 are altered accordingly. The volume of rubber is given by way of example only. For any given gasket, the volume of rubber is varied according to the requirements of the given gasket; for example depending on the application for which it is to be used.
[0067] The width of the gasket 1 (FIG. 5-E), excluding the shoulders 13, in this further embodiment is about 32 mm and the height of the main body of the gasket 1 (FIG. 5-F), excluding the anchoring legs 5 is about 20 mm. The height of each shoulder 13 from the base of the gasket (FIG. 5-G) is about 9 mm. The width of the base of the gasket (FIG. 5-H) is about 33 mm. In alternative embodiments, the width of the base of the gasket is about 40 mm or about 45 mm, but all dimensions will vary according to the sealing requirements and the application of the TSG.
[0068] As shown in FIG. 5, for the further embodiment shown, the profile of the gasket 1 comprises a plurality of longitudinally extending bores 7 having a circular cross-section and also a plurality of longitudinally extending bores 7b having a substantially semi-circular cross section. The profile comprises two anchoring legs 5 and two shoulders 13 protruding substantially perpendicular to the direction of the anchoring legs 5.
[0069] As shown in FIG. 6, in use, the anchoring legs 5 are cast in to form a groove 25 in a tunnel segment 23. The shoulders 13 of the TSG 1 are configured to protrude substantially parallel to and along the upper face of the TSG 1.
[0070] As shown in FIGS. 7, 8 and 9, a first cutting guide 30 is used to extrude a first tunnel segment gasket (not shown) along a curing line. As shown in FIG. 9, the cutting guide 30 comprises a bottom plate 32 and a top plate 31. The bottom plate 32 comprises a channel 33. As shown in FIG. 8, the cross-section of the channel 33 is shaped according to the gasket profile that is required. The angle of the channel 33 to the outer faces of the cutting guide is also carefully selected according to the required angle of the joint that is to be formed by the TSG.
[0071] As shown in FIGS. 10, 11 and 12, a second cutting guide 35 is used to extrude a first tunnel segment gasket (not shown). As shown in FIG. 10, the cutting guide 35 comprises a bottom plate 37 and a top plate 36. The bottom plate 37 comprises a channel 38. As shown in FIG. 9, the cross-section of the channel 33 is shaped according to the gasket profile that is required. The angle of the channel 38 to the outer faces of the cutting guide is also carefully selected according to the required angle of the joint that is to be formed by the TSG.
[0072] Referring to FIG. 13, the first and second cutting guides 30, 35 form the left hand and right hand guides for forming the corner joint of two tunnel segment gaskets 41, 42, as shown in FIGS. 15 and 16. To form the corner joint a first tunnel segment gasket 41 is extruded through the channel 33 of the left hand cutting guide 30, shown in FIG. 7. A second tunnel segment gasket 42 is extruded through the channel 38 of the right hand cutting guide 35.
[0073] Referring to FIG. 14, two rotating blades 40a, 40b are used to accurately cut the end surface of each of the two extruded tunnel segment gaskets 41, 42 whilst they are held within the respective cutting guides 30, 35.
[0074] Referring to FIG. 15, the present invention also provides a method of manufacturing a tunnel segment gasket joint. A first and second tunnel segment gasket 40, 41 are joined together by shooting in a thin film of rubber 43, as shown in FIG. 17. The thin film shot joint 43 is applied to the first and second tunnel segment gaskets 40, 41 whilst they are clamped in the required position. The increased accuracy of the cutting of the extruded TSGs together with the increased accuracy of the joining is such that the profile of the gasket 40, 41 is substantially unchanged by the joining method, as shown in FIG. 13. The joining method of the present invention provides a stronger, fully vulcanised joint. The optional curved protrusions, at the base of the gasket ensure that not only is the desired angle achieved at the joint but the joint profile is maintained to allow for secure sealing without the risk of split propagation.
[0075] Referring to FIG. 16, the cutting guides allow for the angle 46 at the joint to be obtuse, as shown in FIG. 16 or to be acute, as shown in FIG. 18, or to be a 90-degree angle, if required. The increased accuracy of the angle at the joint improves the performance of the TSGs when positioned to join tunnel segments. This capability to produce any required joint angle also ensures an accurate fit with the segment with which the TSG is to be used.
[0076] The above described embodiment has been given by way of example only, and the skilled reader will naturally appreciate that many variations could be made thereto without departing from the scope of the claims.
