Anchorage arrangement

Abstract

The invention relates to an anchorage arrangement (100) for anchoring a cable including a plurality of wires and / or strands (104) to a building structure, said anchorage arrangement (100) comprising an anchorage unit (102) for fixing free ends of said wires and / or strands (104) and comprising an anchorage spacer unit (108) including a plurality of through-holes for passing said wires and / or strands (104) therethrough in a widened configuration, and a compacting clamp unit (124) for compacting the wires and / or strands (104) in a side-by-side configuration and being located at a predetermined distance from said anchorage unit (102). According to the invention, the anchorage arrangement (100) further comprises a further spacer unit (130) located between said anchorage spacer unit (102) and said compacting clamp unit (124), said further spacer unit (130) including a plurality of through-holes (130a) for passing said wires and / or strands (104) therethrough in a further widened configuration.

Description

[0001] Anchorage Arrangement

[0002] Description

[0003] The invention relates to an anchorage arrangement for anchoring a cable including a plurality of wires and / or strands to a building structure, said cable, said wires and / or strands and said building structure not being part of the anchorage arrangement, said anchorage arrangement comprising an anchorage unit adapted and intended for being fixed to said building structure, adapted and intended for fixing free ends of said wires and / or strands and comprising an anchorage spacer unit, said anchorage spacer unit including a plurality of through-holes adapted and intended for passing said wires and / or strands therethrough in a widened configuration, and said anchorage arrangement further comprising a compacting clamp unit adapted and intended for compacting the wires and / or strands in a side-by-side configuration and being located at a predetermined distance from said anchorage unit.

[0004] Such anchorage arrangements have been successfully marketed by the applicant for many years under the tradename Dyna Grip®.

[0005] Within the anchorage unit, the free ends of the wires and / or strands run essentially parallel to each other, being spaced apart from each other in accordance with the widened configuration of the anchorage spacer unit by a distance which is large enough to allow them to be held in a wedge plate by means of wedge elements. At the outlet of the anchorage spacer unit, the wires and / or strands are deflected so that they gradually approach each other outside the anchorage unit until they are arranged in the compacting clamp unit in the side-by-side configuration.

[0006] This kind of arrangement assumes that the anchorage unit, which is located inside the building structure, is almost perfectly aligned with the tangent of the catenary of the cable at the entrance to the anchorage unit. Deviations from this perfect alignment must not exceed an angle in the order of 2°.

[0007] In practice, however, even with newly erected building structures, it is not uncommon for the alignment of the anchorage unit not to meet these requirements. In this case, there is a too large deflection at the outlet of the anchorage spacer unit, which in turn leads to too much stress on the wires and / or strands, which limits their service time.

[0008] In addition, the development of cables has made great progress in recent years, so that if an old, heavy cable is replaced by a modern cable, this modern cable will follow a different catenary than the old cable due to its lower weight, which in turn results in an excessive deviation between the tangent of the catenary of the new cable and the alignment of the anchorage unit.

[0009] During construction and service stage of the bridge, also large angular rotations due to deflections of the structure, rotation of the structure at the anchorage points of the cable, change of cable sag due to change in cable force, static and dynamic wind loads on the cable occur. Especially at long span bridges such angular rotations can reach values of more than 1 ° which need to be added to the structural tolerances of the alignment of the bridge and which are variable in direction.

[0010] Finally, in the case of cable stayed bridges, such excessive deviations can also result from the desire to raise the bridge deck at the same time of replacing the cables, for example to increase the clearance height for ships.

[0011] It is therefore the object of the present invention to provide an anchorage arrangement which fulfills the above-mentioned requirements without resulting in excessive stress on the wires and / or strands.

[0012] According to the invention, this object is achieved by an anchorage arrangement of the afore- mentioned type which further comprises a further spacer unit located between said anchorage spacer unit and said compacting clamp unit, said further spacer unit including a plurality of through-holes adapted and intended for passing said wires and / or strands therethrough in a further spacer unit widened configuration.

[0013] The inventors have recognized that in all the cases described above the necessary deflection of the wires and / or strands is composed of two components, namely on the one hand the unavoidable radial-symmetric deflection for transferring the wires and / or strands from the widened configuration required for anchoring to the side-by-side configuration required for the main length of the cable, and on the other hand a deflection resulting purely from the specific constellations of the afore-described static and dynamic deflection causes. The inventors have also recognized that it is possible to have these two components received by the wires and / or strands at length sections spatially separated from each other in the longitudinal direction of the cable. According to the invention, this spatial separation is achieved by providing a further spacer unit in addition to the anchorage spacer unit. While the further spacer unit mainly merges / widens the wires and / or strands between the widened configuration and the side-by-side configuration, the deflections resulting from the above-described causes are mainly taken over by the anchorage spacer unit, which in this case therefore fulfills the function of a deviator unit.

[0014] In existing building structures, the anchorage unit may be located relatively deep in the building structure. So there is a risk that the wires and / or strands will, on their way out of the building structure, come into contact with the side walls of the channel leading from the anchorage unit to the outlet of the building structure. Such a contact would also be detrimental to the service time of the cables. It is therefore proposed that the anchorage arrangement further comprises a guide spacer unit located between said anchorage spacer unit and said further spacer unit, said guide spacer unit including a plurality of through-holes adapted and intended for passing said wires and / or strands therethrough in a guide spacer unit widened configuration. In this case, the guide spacer unit assumes the function of the deviator unit, while the anchorage spacer unit only has the function of maintaining the widened configuration. Between the anchorage spacer unit and the guide spacer unit, the wires and / or strands therefore preferably run substantially parallel to the channel leading from the anchorage unit to the outlet of the building structure, so that there is no risk of contact with the channel wall.

[0015] From the outlet of the building structure, the deflection resulting from the case constellations described above are then taken over by the guide spacer unit, while the further spacer unit, also in this case, is responsible mainly for the merging / widening of the wires and / or strands.

[0016] It should be noted that the word “between” in “the further spacer unit is located between said anchorage spacer unit and said compacting clamp unit” is to be understood as referring to the fact that the further spacer unit has a predetermined non-zero distance from both said anchorage spacer unit and said compacting clamp unit. In other words, the only physical contact of the further spacer unit to both the anchorage spacer unit (or the guide spacer unit) and the compacting clamp unit is made by free length sections of the wires and / or strands running between the further spacer unit, on the one side, and the anchorage spacer unit (or the guide spacer unit) and the compacting clamp unit, respectively, on the other side.

[0017] It should also be pointed out that the solution according to the invention can be retrofitted in a simple and cost-effective manner, since only one or two additional spacer units need to be provided in each anchorage arrangement.

[0018] In a further development of the invention, it is proposed that the anchorage arrangement further comprises an exit pipe adapted and intended for surrounding the wires and / or strands and adapted and intended for being fastened to an outer surface of the building structure, said further spacer unit being located inside said exit pipe or adjacent a free end of said exit pipe outside said exit pipe and / or that the guide spacer unit is located at a further predetermined distance from the free end of said exit pipe, the further predetermined distance amounting to between about 0.3 m and about 1 .0 m. Advantageously, the further spacer unit can be a floating spacer unit, i.e. a spacer unit having contact neither to the anchorage nor to the exit pipe thereof. In this way it is ensured that the further spacer unit focuses on the radial-symmetric deflection transferring the wires and / or strands from the widened configuration required for anchoring to the side-by-side configuration required for the main length of the cable. As it is true for the compacting clamp unit, also the floating further spacer unit can be held in place merely by the frictional forces acting between the wires and / or strands on the one side and the further spacer unit on the other side, and this is true even taking weather-related dynamic forces into account.

[0019] In order that the deflection of the wires and / or strands can take place as gently as possible, it is proposed that at least a portion of the inner wall of the through-holes of at least one of the spacer units, i.e. anchorage spacer unit and / or further spacer unit and / or guide spacer unit, is arcuate. The arcuate shape can have a predetermined curvature, wherein a radius of the predetermined curvature can, for example, amount to at least 2 m, preferably at least 4 m, even more preferably to at least 4.3 m. However, also other shapes of the arcuate inner wall of the through-holes are conceivable, e.g. a clothoid-shape.

[0020] Depending on the function of the respective spacer unit, the arcuate portions can be designed and / or oriented differently. For example, the through-holes of the anchorage spacer unit can be funnel-shaped widening away from the anchorage unit. Furthermore, the arcuate portions of the inner walls of the through-holes of the further spacer unit can be directed towards a central axis of the further spacer unit. Analogously, the arcuate portions of the inner walls of the through-holes of the guide spacer unit may be directed all in the same direction.

[0021] Preferably, the widened configuration of the anchorage spacer unit, the further spacer unit widened configuration and the guide spacer unit widened configuration, with exception of the design of the arcuate wall portions, can be identical. Preferably, at least one of the anchorage spacer unit, the further spacer unit and the guide spacer unit may be made from polyethylene, e.g. HDPE.

[0022] Furthermore, at least one of the anchorage spacer unit, the further spacer unit and the guide spacer unit can comprise a plurality of, e.g. disk-shaped, spacer subunits each including a plurality of through-holes adapted and intended for passing said wires and / or strands therethrough, at least one of the plurality of spacer subunits being made from a material selected from HDPE, plastic foam, rubber, steel and high strength grout. In this way, predetermined properties going beyond the mere deflection can be attributed to the spacer unit(s), e.g. sealing properties.

[0023] In the following the invention will be explained in more detail referring to embodiments shown in the drawing:

[0024] Figure 1 shows a bridge deck side anchorage including an anchorage arrangement according to the invention;

[0025] Figure 2 shows a pylon side anchorage including an anchorage arrangement according to the invention;

[0026] Figure 3 shows a first embodiment of an anchorage arrangement according to the invention having the same basic design as the anchorage arrangements of Figure 1 and 2;

[0027] Figure 4 shows a second embodiment of an anchorage arrangement according to the invention;

[0028] Figures 5a and 5b show a sectional view (Figure 5a) and a front view (Figure 5b) seen in the direction of arrow P1 in Figure 5a of an embodiment of the further (floating) spacer unit; Figures 6a and 6b show a sectional view (Figure 6a) and a front view (Figure 6b) seen in the direction of arrow P2 in Figure 6a of an embodiment of the guide spacer unit; and

[0029] Figure 7 shows an embodiment of an anchorage arrangement known from the prior art.

[0030] In Figure 1 an anchorage arrangement according to the present invention is generally denoted by reference numeral 100.

[0031] The anchorage arrangement 100 includes an anchorage unit 102 fixing a plurality of wires and / or strands 104 to a bridge deck 106.

[0032] As may be seen in detail from Figure 3, the free ends of the wires and / or strands 104 run essentially parallel to each other within the anchorage unit 102, being spaced apart from each other in accordance with the widened configuration of an anchorage spacer unit 108 by a distance which is large enough to allow them to be held in a wedge plate 110 by means of wedge elements 112. The wedge plate 110 abuts against an anchor plate 114 which in turn abuts against the bridge deck 106 (see also Figure 1 ). An anchor tube 116 extends from anchor plate 114 into a channel 118 of the bridge deck 106.

[0033] With reference again to Figure 1 , an exit pipe 120 is mounted to the bridge deck 106 at the end of the channel 118. Furthermore, a vandalism protection tube 122 is connected to the exit pipe 120. Inside the vandalism protection tube 122 a compaction clamp 124 is provided. Starting from the compaction clamp 124 the wires and / or strands 104 are extending in a side-by-side configuration towards the respective other, substantially identically designed anchorage arrangement 100 located at the bridge pylon 126 (see Figure 2).

[0034] As is shown in Figure 1 , the actual extension E1 of the wires and / or strands 104 in the side-by-side configuration deviates from the axial extension E2 of the anchorage unit 102 and the bridge deck channel 118 by an angle [3. In the following, the problems arising from this deviation will be explained referring to Figure 7 showing a prior art anchor arrangement 900.

[0035] In the prior art anchor arrangement 900, the entire deflection of the wires and / or strands 904, i.e. the deflection caused by the compaction of the wires and / or strands 904 from the widened configuration at the anchorage spacer unit 908 to the side-by-side configuration at the compaction clamp 924, on the one side, and the afore-mentioned deviation (angle (3) , on the other side, occurs at the outlet end of the anchorage spacer unit 908. As a result, wire and / or strand 904a has to take a maximum deflection, while wire and / or strand 904b shows an almost undeflected extension. The excessive deflection of wire and / or strand 904a causes too much stress, and thus the risk of limited service time.

[0036] It should be noted that the same problem arises when the wires and / or strands are not deflected at the anchorage spacer unit 108, but at a guide spacer unit 128 (see Figures 1 and 3). According to the invention, such guide spacer units 128 can be provided at or close to the end of the channel 1 18, in order to ensure a substantially parallel, in other words undeflected, extension of the wires and / or strands 104 inside the channel.

[0037] In order to provide a solution to the afore-described problem, the invention suggests to provide a further spacer unit 130 between the guide spacer unit 128 (or the anchorage spacer unit 108, if there is no need for a guide spacer unit 128 in view of a short enough length of the channel 1 18) and the compaction clamp 124. The purpose of this further spacer unit 130 is to separate the compacting deflection of the wires and / or strands 104 from the widened configuration at the anchorage spacer unit 108 to the side-by-side configuration at the compaction clamp 124 from the deflection caused by the deviation (angle [3).

[0038] In particular, the further spacer unit 130 deals with the compacting deflection, while the deviation deflection is handled by the guide spacer unit 128 (or the anchorage spacer unit 108), as may be best seen from Figure 3. Consequently, wire and / or strand 104a is considerably less deformed as compared to wire and / or strand 904a of the prior art anchorage arrangement 900. The fact that wire and / or strand 104b shows a higher deformation than wire and / or strand 904b of the prior art anchorage arrangement 900 is acceptable in view of the more uniform deformation distribution among the entirety of the wires and / or strands 104.

[0039] In this context, it should be noted that the most uniform deformation distribution can be achieved if the further spacer unit 130 is a floating spacer unit, i.e. a spacer unit which merely contacts the wires and / or strands 104, but is free of contact from any other component of the anchorage arrangement 100, in particular the anchor tube 116. Nevertheless, the floating spacer tube 130 is safely held in place by the frictional forces between itself and the wires and / or strands 104, as this is, as a side remark, true for the compacting clamp 124 as well.

[0040] Figure 5a shows a sectional view of the further spacer unit 130, and Figure 5b shows a front view seen in the direction of arrow P1 in Figure 5a of the further spacer unit 130.

[0041] As can be seen from Figure 5a, the further spacer unit 130 includes a plurality through-holes 130a extending therethrough, each receiving one of the wires and / or strands 104. At least a portion 130a1 of the inner wall of the through-holes 130a has an arcuate shape allowing to support the wires and / or strands 104 while being deflected and thus ensuring a uniform distribution of the deflection-related forces over a predetermined distance. As the further spacer unit 130 is responsible merely for the compacting deflection, the arcuate inner wall portions 130a1 of the through-holes 130a all are pointing towards a central axis A of the further spacer unit 130.

[0042] Figures 6a and 6b show analogous views of the guide spacer unit 128.

[0043] As can be seen from Figure 6a, the guide spacer unit 128 includes a plurality through-holes 128a extending therethrough, each receiving one of the wires and / or strands 104. At least a portion 128a1 of the inner wall of the through-holes 130a has an arcuate shape allowing to support the wires and / or strands 104 while being deflected and thus ensuring a uniform distribution of the deflection-related forces over a predetermined distance. As the guide spacer unit 128 is responsible for the deviation deflection the direction of which cannot be predicted, and as the guide spacer unit 128, in particular in view of the floating arrangement of the further spacer unit 130, is responsible for dynamic deflections caused, for example, by wind and rain, the arcuate inner wall portions 128a1 of the through- holes 128a all are designed as funnel-shaped wall portions.

[0044] For the sake of completeness, Figure 4 shows a further embodiment of the anchorage arrangement according to the present invention, namely the aforementioned embodiment not including a guide spacer unit. As the embodiment according to Figure 4 substantially corresponds to the embodiment of Figure 3, all elements are designated by the same reference numerals as in Figure 3, but increased by 100. Furthermore, the anchorage arrangement 200 of Figure 4 will be described only insofar as it differs from the anchorage arrangement 100 of Figure 3, to the description of which it is otherwise explicitly referred to.

[0045] As already mentioned, the anchorage arrangement 200 of Figure 4 differs from the anchorage arrangement 100 of Figure 3 only by the fact that it fails to include a guide spacer unit. This is possible because the anchor tube 216 is short enough to avoid the risk of an undesired contact of one of the wires and / or strands 204 and / or the floating spacer unit 230 with the anchor tube 216. With respect to the anchor plate 214, the wedge plate 210, the wedge elements 212, the anchorage spacer unit 208 and the compacting clamp 224, the design of the anchorage arrangement 200 of Figure 4 is identical to that of the anchorage arrangement 100 of Figure 3.

[0046] Returning to Figure 3, the anchorage spacer unit 108 comprises a plurality of, e.g. disk-shaped, spacer sub-units 108a, each including a plurality of through-holes 108b adapted and intended for passing said wires and / or strands 104 therethrough. Although not shown in the drawings, the further spacer unit 130 and / or the guide spacer unit 128 as well may include a plurality of, e.g. diskshaped, spacer sub-units.

Claims

Claims1 . Anchorage arrangement (100) for anchoring a cable including a plurality of wires and / or strands (104) to a building structure (106, 126), said cable, said wires and / or strands and said building structure not being part of the anchorage arrangement, said anchorage arrangement (100) comprising:• an anchorage unit (102) adapted and intended for being fixed to said building structure (106, 126), adapted and intended for fixing free ends of said wires and / or strands (104) and comprising an anchorage spacer unit (108), said anchorage spacer unit (108) including a plurality of through-holes adapted and intended for passing said wires and / or strands (104) therethrough in a widened configuration, and• a compacting clamp unit (124) adapted and intended for compacting the wires and / or strands (104) in a side-by-side configuration and being located at a predetermined distance from said anchorage unit (102), wherein the anchorage arrangement (100) further comprises a further spacer unit (130) located between said anchorage spacer unit (102) and said compacting clamp unit (124), said further spacer unit (130) including a plurality of through-holes (130a) adapted and intended for passing said wires and / or strands (104) therethrough in a further widened configuration.

2. Anchorage arrangement according to claim 1 , wherein the anchorage arrangement (100) further comprises an exit pipe (120) adapted and intended for surrounding the wires and / or strands (104) and adapted and intended for being fastened to an outer surface of the building structure (106, 126), said further spacer unit (130) being located inside said exit pipe (120) or adjacent a free end of said exit pipe (120) outside said exit pipe (120).

3. Anchorage arrangement according to claim 1 or 2, wherein the further spacer unit (130) is a floating spacer unit, i.e. a spacer unit being not in contact with the anchorage unit (102) or to the exit pipe (120) thereof.

4. Anchorage arrangement according to any of claims 1 to 3, wherein the anchorage arrangement (100) further comprises a guide spacer unit (128) located between said anchorage spacer unit (108) and said further spacer unit (130), said guide spacer unit (128) including a plurality of through-holes (128) adapted and intended for passing said wires and / or strands (104) therethrough in a widened configuration.

5. Anchorage arrangement according to claims 2 and 4, wherein the guide spacer unit (128) is located at a further predetermined distance from the free end of said exit pipe (120) .

6. Anchorage arrangement according to any of claims 1 to 5, wherein at least a portion (128a1 , 130a1 ) of the inner wall of the through- holes (128a, 130a) of at least one of the spacer units, anchorage spacer unit, further spacer unit (130) and guide spacer unit (128), is arcuate having a predetermined curvature.

7. Anchorage arrangement according to claim 6, wherein a radius of the predetermined curvature amounts to at least 2 m, preferably at least 4 m, even more preferably to at least 4.3 m.

8. Anchorage arrangement according to any of claims 1 to 7, wherein the through-holes of the anchorage spacer unit (108) are funnel- shaped widening away from the anchorage unit (102).

9. Anchorage arrangement according to any of claims 1 to 8,wherein the arcuate portions (130a1 ) of the inner walls of the through- holes (130a) of the further spacer unit (130) are directed all towards a central axis (A) of the further spacer unit.

10. Anchorage arrangement according to any of claims 1 to 9, wherein the arcuate portions (128a1 ) of the inner walls of the through- holes (128a) of the guide spacer unit (128) are funnel-shaped widening away from the anchorage unit (102).11 . Anchorage arrangement according to any of claims 1 to 10, wherein at least one of the anchorage spacer unit (108), the further spacer unit (130) and the guide spacer unit (128) is made from polyethylene, e.g. HDPE.

12. Anchorage arrangement according to any of claims 1 to 11 , wherein at least one of the anchorage spacer unit (108), the further spacer unit and the guide spacer unit comprises a plurality of, e.g. disk-shaped, spacer sub-units (108a) each including a plurality of through-holes (108b) adapted and intended for passing said wires and / or strands (104) therethrough, at least one of the plurality of spacer sub-units (108a) being made from a material selected from HDPE, plastic foam, rubber, steel and high strength grout.

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