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Title:
A SEALING SYSTEM
Document Type and Number:
WIPO Patent Application WO/2024/086859
Kind Code:
A1
Abstract:
According to one aspect of the invention there is provided a sealing system for a mechanical anchor comprising, a first pipe (2) for discharging a settable liquid, a second pipe (3) through which a fluid can be displaced, a retainer device (20) for locating the tendon (1) to be anchored, the first pipe (2) and second pipe (3) and a sealing means associated with the retainer device (20), located between a proximal and a distal end of the tendon (1), wherein the sealing means expands into the hole and the surrounding cavities of the hole (8, 13) in which the tendon is to be anchored, the settable liquid being pumped through the first pipe (2) at the distal end of the tendon (1), the settable liquid entering the sealing means which becomes semi-saturated with said settable liquid, the settable liquid setting within the confines of the sealing means impeding the flow of settable liquid past the sealing means, further where the systematic pumping of the settable liquid displaces the air in the hole through the second pipe (3), thereby creating a seal between a distal and a proximal end of the tendon.

Inventors:
VILJOEN STEFAN DU TOIT (ZA)
BEKKER ADRIAN ROBERT (ZA)
Application Number:
PCT/ZA2023/050064
Publication Date:
April 25, 2024
Filing Date:
October 18, 2023
Export Citation:
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Assignee:
WEKABA ENG PTY LTD (ZA)
International Classes:
E02D5/80; E02D5/54; E02D5/76; E21D20/02; E21D21/00
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Claims:
the first pipe at the distal end of the tendon, the settable liquid entering the sealing means which becomes semi-saturated with said settable liquid, the settable liquid setting within the confines of the sealing means which impedes the flow of settable liquid past the sealing means, further where the systematic pumping of the settable liquid displaces the air in the hole through the second pipe, thereby creating a seal between a distal and a proximal end of the tendon. 2. The sealing system as claimed in claim 1 wherein the sealing system comprises of a porous mesh material. 3. The sealing system as claimed in any of claims 1 and 2 wherein the sealing means have semipermeable properties; 4. The sealing system as claimed in any of claims 1 to 3 wherein the porous sealing means extends into the surrounding cavities of a hole when pressure is applied thereon. 5. The sealing system as claimed in any of claims 1 to 4 wherein the porous sealing means extends into the surrounding cavities by the application of pressure generated by the insertion of the anchor system into the hole in which the tendon is to be anchored. 6. A seal for use with a mechanical anchor comprising: a plurality of elongate flexible filamentary seal elements associated with the mechanical anchor. 7. The seal as claimed in claim 6, the seal further comprising a longitudinal axis and the seal elements spaced angularly around and longitudinally along the axis such that they protrude outwardly from the axis. 8. The seal as claimed in any of claims 6 to 7 including at least one elongate core which defines the longitudinal axis and to which a plurality of the seal elements is attached.

9. The seal as claimed in any of claims 6 to 8 wherein the seal elements protrude radially from the longitudinal axis. 10. The seal as claimed in any of claims 6 to 9 wherein the seal elements are located adjacent to a portion of the tendon. 11. A seal for use with a mechanical anchor comprising: a plurality of permeable and pliable sealing members, the sealing members being secured to one or more components of the mechanical anchor, the sealing members having elongate seal elements extending outwardly from the sealing members, wherein a settable liquid can be discharged within the confines of the sealing members and set therein, creating a seal between one end of a tendon and another end of the tendon. 12. A seal assembly comprising: at least one seal of the type described in claim 6 or claim 11 and an attachment means configured to attach the seal to a component of a mechanical anchor. 13. The seal assembly as claimed in claim 12 wherein the seal is attached to the tendon of a mechanical anchor. 14. The seal assembly as claimed in any of claims 12 or 13 wherein the attachment means includes a collar which can be secured to the tendon and to which the core of the seal element is connected. 15. The seal assembly as claimed in any of claims 12 to 14 wherein the seal assembly includes a plurality of seals, the cores of which are connected to the attachment means.

16. A method of installing a mechanical anchor in a hole drilled in rock including the steps of: inserting at least one seal as described herein into the hole; pumping a settable liquid into the hole; the settable liquid entering the confines of the seal; the settable liquid becoming associated with the seal impeding the flow of further settable liquid past the seal. 17. A mine having a hanging wall which is supported by a plurality of mechanical anchors installed in holes drilled in the hanging wall, at least some of the mechanical anchors having at least one seal of the type described herein positioned in the associated hole. ABSTRACT According to one aspect of the invention there is provided a sealing system for a mechanical anchor comprising, a first pipe for discharging a settable liquid, a second pipe through which a fluid can be displaced, a retainer device for locating the tendon to be anchored, the first pipe and second pipe and a sealing means associated with the retainer device, located between a proximal and a distal end of the tendon, wherein the sealing means expands into the hole and the surrounding cavities of the hole in which the tendon is to be anchored, the settable liquid being pumped through the first pipe at the distal end of the tendon, the settable liquid entering the sealing means which becomes semi-saturated with said settable liquid, the settable liquid setting within the confines of the sealing means impeding the flow of settable liquid past the sealing means, further where the systematic pumping of the settable liquid displaces the air in the hole through the second pipe, thereby creating a seal between a distal and a proximal end of the tendon.

Description:
A SEALING SYSTEM This invention relates to a sealing system. More particularly, a sealing system for use with a mechanical anchor. It further relates to a seal assembly and to a method of installing a mechanical anchor in a rock face. BACKGROUND Mechanical anchoring systems are widely used in the mining industry and are critical to ensure that rock roofs and rock faces maintain their integrity and do not collapse onto mine workers. Additionally, such collapses can render a mine inoperable. Mechanical anchoring systems typically include an elongate tendon having an inner end which is secured in a hole bored in a rock face and an outer end which protrudes from the hole and to which a rock support, in the form of a bearing plate or washer, is secured such that it abuts against the rock face around the mouth of the hole to provide support to the rock. Additionally, mechanical anchoring systems are typically secured by means of grouting the Mechanical anchoring systems into a rock face, along the length of the mechanical anchoring system to avoid the rock face from collapsing which renders the mechanical anchoring system void. The grout not only serves to secure the mechanical anchoring system but also acts to prevent the metallic tendon from corroding. The installation of these mechanical anchors involves inserting the inner end into a predrilled hole in the rock face and securing it in position, whether mechanically or chemically (by means of a settable substance) a combination of the two or in any other way. Once the inner end of the tendon is secured in the hole it is grouted in position. This process involves pumping a settable grout into the hole around the tendon and allowing it to set. The grout then serves structurally to support the rock around the tendon and prevent it from collapsing the hole which could compromise the structural integrity of the mechanical anchor. Generally, the holes are drilled upwardly into the rock face, and it is accordingly necessary to take steps to reduce the risk that the grout which is pumped into the hole will simply flow downwardly under the influence of gravity out of the mouth of the hole. In order to prevent this from happening, use is made of a plug or seal which is inserted into the hole. The grout is pumped into the hole through a filler pipe inserted into the hole. In addition, a breather pipe is inserted into the hole in order to permit air which is inside the hole, and which is displaced by the grout to escape from the hole. Accordingly, the seal or plug needs to provide a seal around each of the tendon, the filler pipe, and the breather pipe as well as against the inner surface of the hole. However, these filler pipes often prove ineffective as each drilled hole to be filled with grout is different making it difficult to seal the hole entirely with grout since a lot of the grout seeps past the seal. Moreover, air bubbles are often caught by the filling of the hole with grout which is difficult to remove which negatively affects the integrity of the anchor system. Alternatively, current methods for sealing the grout in the hole also include a plug which is inserted into the hole alongside the Mechanical and piping, which is also inefficient since it inadequately accounts for the geometric characteristics of the anchoring system and surrounding rock conditions. Other methods for sealing the grout in the hole also inserting or creating a gasket between the rock and the plate which is typically manufactured from foam, rubber or plastic and/or pre- installed on the Mechanical and therefore fail to account for the particular geometric characteristics of the anchoring system and the surrounding rock conditions. With existing grout seals, components of the Mechanical anchor may have to be removed and reinstalled during the installation process. Failure to account for the aforementioned can often lead to ineffective sealing and securing of the Mechanical anchoring system in the ground, which evidently, is both ineffective and extremely dangerous. In addition, certain of the grout seals of which the Inventor is aware are relatively costly which increases the total cost associated with the mechanical anchor. The current methods have lengthy installation times in addition to the risk that components may be lost during such installation or repairs. Accordingly, the current means for securing a mechanical anchoring system in a rock face is reduced to the effectiveness of how well the grout can be retained in the hole by means of a seal. Therefore, a need exists for a means to effectively secure a tendon in a rock face which is both time and cost effective and where the grout can be retained in the relevant areas effectively. It is an object of the present invention to provide for a solution that, at least partially, alleviate some of the aforementioned disadvantages. SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a sealing system for a mechanical anchor comprising: a first pipe for discharging a settable liquid, a second pipe through which a fluid can be displaced, a retainer device for locating the tendon to be anchored, the first pipe and second pipe and a sealing means associated with the retainer device, located between a proximal and a distal end of the tendon, wherein the sealing means expands into the hole and the surrounding cavities of the hole in which the Mechanical is to be anchored, the settable liquid being pumped through the first pipe at the distal end of the Mechanical, the settable liquid entering the sealing means which becomes semi-saturated with said settable liquid, the settable liquid setting within the confines of the sealing means impeding the flow of settable liquid past the sealing means, further where the systematic pumping of the settable liquid displaces the air in the hole through the second pipe, thereby creating a seal between a distal and a proximal end of the tendon. The sealing means comprises of a porous mesh material. The sealing means having semipermeable properties. The porous sealing means extends into the surrounding cavities of a hole when pressure is applied thereon. The porous sealing means extends into the surrounding cavities by the application of pressure generated by the insertion of the anchor system into the hole in which the item is to be anchored. According to a second aspect of the invention, there is provided a seal for use with a Mechanical anchor which seal includes a plurality of elongate flexible filamentary seal elements that are associated with the mechanical anchor. The seal may include a longitudinal axis and the seal elements may be spaced angularly around and longitudinally along the axis such that they protrude outwardly from the axis. The seal may include at least one elongate core which defines the longitudinal axis and to which a plurality of the seal elements is attached. The seal elements may protrude radially from the longitudinal axis. The seal elements may be located adjacent to a portion of the tendon. According to yet another aspect of the invention there is provided a seal for use with a mechanical anchor which seal includes a plurality of permeable and pliable sealing members, the sealing members being secured to one or more components of a mechanical anchor, the sealing members having elongate seal elements extending outwardly from the sealing members, where a settable liquid can be discharged within the confines of the sealing members and set therein whereby a seal is created between one end of a tendon and another end of the tendon. According to another aspect of the invention, there is provided a seal assembly which includes at least one seal of the type described above with an attachment means configured to attach the seal to a component of a mechanical anchor. The seal may be attached to a tendon of a mechanical anchor. The attachment means may include a collar which can be secured to the tendon and to which the core of the seal element is connected. The seal assembly may include a plurality of seals, the cores of which are connected to the attachment means. According to yet another aspect of the invention there is provided a method of installing a Mechanical anchor in a hole drilled in rock, which method includes the steps of inserting at least one seal of the type described above into the hole, pumping a settable liquid into the hole, the settable liquid entering the confines of the seal, the settable liquid becoming associated with the seal impeding the flow of further settable liquid past the seal. According to yet another aspect of the invention there is provided a mine having a hanging wall which is supported by a plurality of mechanical anchors installed in holes drilled in the hanging wall, at least some of the mechanical anchors having at least one grout seal of the type described above positioned in the associated hole. The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings. BRIEF DESCRIPTION OF THE DRAWINGS A sealing system in accordance with the invention will now be described by way of the following, non-limiting examples with reference to the accompanying drawings. In the drawings: - Figure 1 is a perspective view showing a first embodiment of a sealing system, in an unfolded position to be received by the retainer device; Figure 2 is a perspective view of Figure 1 showing the unfolded seal with the retainer device retaining the Mechanical and the position for the inlet and the outlet provided for by the retainer. Figure 3 is a perspective view showing the sealing system with the seal unfolded; Figure 4 is a sectional side view of the sealing system, with the seal folded down, as placed with the hole to be filled with grout and sealed therewith; Figure 5 is a sectional side view of the sealing system in use indicating the flow of grout through the inlet and filling up the hole and surrounding cracks in the ground; Figure 6 is a sectional side view of the hole with the sealing system, in use after the hole and the surrounding cracks in the ground have been filled entirely with grout to secure the tendon; Figure 7 is a sectional bottom view of the hole depicting the sealing system with the seal folded downward which also shows the spaces between the mechanical anchor components and the cable/tendon to be filled with grout; and Figure 8 is a sectional bottom view of the hole depicting how the grout has managed to fill the entire hole and permeate through the seal to contact the walls of to secure the Mechanical in the ground. Figure 9 shows a perspective view of a sealing system in accordance with a second embodiment of the invention; Figure 10 shows a side view of the sealing system as shown in Figure 9; Figure 11 shows a three-dimensional view of a seal assembly in accordance with another embodiment of the invention; Figure 12 shows a three-dimensional fragmentary view of a Mechanical anchor installation incorporating the seal assembly of Figure 11; Figure 13 shows a front view of the installation of Figure 12; Figure 14 shows a top perspective view of a sealing member in accordance with another embodiment of the invention; Figure 15 shows a bottom perspective view of the sealing member of Figure 14; Figure 16 shows a perspective view of the sealing member of Figure 14 configured to a tendon/Mechanical to be anchored before insertion into a hole; Figure 17 shows a perspective view of the sealing member when inserted into a hole; Figure 18 is a sectional side view of the sealing system, with the seal folded down, as placed in the hole to be filled with grout and sealed therewith; Figure 19 is a sectional bottom view of the hole depicting the sealing system with the seal folded downward which also shows the spaces occupied by the sealing member; and Figure 20 is a sectional side view of the hole with one embodiment of the sealing system, in use after the hole and the surrounding cracks in the ground have been filled entirely with grout to secure the tendon. In Figures 9 and 10 of the drawings, reference numeral 10 refers generally to a grout seal in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings in which like numeral refer to like features, a sealing system is generally indicated by reference numeral 10. In a first embodiment of the invention, as shown in Figures 1; 2 and 4, a retainer device 20 consisting of a bottom half 21 and a top half 22 capable of being joined to one another to enable the retainer device 20 to retain a tendon 1, a first pipe 2 (also referred to as an inlet), through which grout or another settable liquid can be pumped and a second pipe 3 (also referred to as an outlet), through which air can be displaced within the hole. The retainer is also capable of retaining the sealing member 4 in between the bottom half 21 and the top half 22 of the retainer device 20 to be capable of being folded downward before being placed in the hole 5. In one embodiment of the invention, and as shown in Figures 2 and 3, the item 1 can be an elongated object, such as, a wire, a pole and most preferably, a cable or tendon 1. The tendon 1, should be sized and shaped so that it can be retained by the retainer device 20 and which is capable of receiving material 7 to be used to fill and secure the item 1 in the hole 5. As shown in Figure 6, the material 7 for filling the hole 5 can be any of cementitious material, wax, plastic, or any other material capable of filling the hole in the ground as well as the surrounding cracks 8 and spaces between the inlet 2 and the outlet 3 up to the bottom half 21 of the retainer 20. Preferably, the material will be grout or cement or any other material capable of hardening to ensure that the tendon 1 is secured in the hole 5 as illustrated in Figures 4 to 6. The outlet 3 is an outlet pipe 3 extending from the lower portion of the hole 5 past the top half 22 of the retainer 3 which is open to the atmosphere 40 to allow for any fluids 11, most likely air bubbles 11, residing in the surrounding cracks 8 and the hole 5 to escape therefrom to ensure that once the grout 7 is received via the inlet pipe 2 and fills up the hole 5 that no fluids 11 remain in the hole 5 whereby ensuring that the entire hole 5 is filled with grout 7 to encourage the tendon 1 to stay secured in the hole 5. With reference to Figures 5; 7 and 8, the device provides for a sealing member 4. The sealing member 4 is made from a material which is pliable to allow for the sealing member 4 once placed in the hole 5 to be sealed, to assume the general geometric conditions of the hole 5 and to facilitate the sealing thereof whilst impeding the seeping of grout 7 to occur past the sealing member 4 towards the surface 12. The sealing member 4 is furthermore made from a material that is semipermeable to allow for the grout 7 to enter the sealing member to the extent that it becomes, to at least some extent, saturated with grout. The grout 7 also fills the spaces between the retained tendon 1, the inlet pipe 2 and outlet pipe 3 and also permeates through the side walls of the hole 13 whereby allowing for the grout 7 to set against the side walls of the hole 13 and secure the tendon 1 in the hole 5. The semipermeable properties of the sealing member 4 are described to include that grout can infiltrate the sealing member where the grout can be allowed to set. The setting of the grout 7 within the confines of the sealing member serves to impede the flow of grout past the sealing member 4. For clarity, the sealing member 4 expands into the cavities adjacent the sealing member 4 so that when the grout 7 is received by the sealing member 4 that the grout extends through the sealing member 4 into the cavities in which the seal extends in order to effectively seal the hole. In use, with reference to Figure 4 and Figure 5, the retainer device 20 will receive and retain the inlet pipe 2, the outlet pipe 3, the sealing member 4, and the tendon 1. The sealing member 4 will be folded downward to, at least partially, cover the retainer device 20 and portions of the inlet pipe 2 and outlet pipe 3 to extend toward the lower region of the hole 14. As grout 7 is received via the inlet pipe 2 in and incrementally filling the hole 5, air bubbles 11 are displaced and able to escape to the atmosphere 40, via the outlet pipe 3. This will ensure that the hole 5 and the cracks 8 are entirely filled with grout 7 and the amount of air bubbles 11 are diminished. By having a diminished amount of air bubbles 11 in the hole 5, it will ensure that the tendon 1 is secured in the hole 5 more effectively. Once the grout 7 has filled the hole 5 entirely, it can harden thereby securing the tendon 1 in the hole 5. As can be seen from Figures 9 to 12, a second embodiment of the invention comprises a grout seal 110 which includes an elongate core 112 which defines a longitudinal axis 114 and a plurality of elongate filamentary seal elements 116 which are connected to and protrude from the core 112. The core 112 is formed from a length of twisted steel wire or tendon and has an attachment formation in the form of a ring 118 connected to one end thereof. The seal elements 116 may be formed from a synthetic plastics material and are attached to the core 112 such that they protrude generally radially therefrom. The seal elements are angularly and longitudinally spaced-apart such that their outer ends together define a generally circular cylindrical seal formation generally indicated by reference numeral 120. Reference is now made to Figure 11 of the drawings, in which reference numeral 130 refers generally to a seal assembly in accordance with another embodiment of the invention. The seal assembly 130 includes a plurality of grout seals 110 and attachment means, generally indicated by reference numeral 132 whereby the seal assembly 130 is connectable to a tendon of a mechanical anchor as described in more detail here below. The attachment means 132 is in the form of a collar to which the rings 118 of the seal elements 116 are connected. Reference is now made to Figures 11 and 12 of the drawings, in which reference numeral 150 refers generally to a mechanical anchor installation in accordance one aspect of the invention. The mechanical anchor installation 150 includes an elongate tendon in the form of a Mechanical 152 having an operatively inner end and an operatively outer end. The seal assembly 130 is connected to the tendon 152 by positioning the collar 132 around the Mechanical 152 at a position spaced longitudinally inwardly from its operatively outer end and crimping the collar in order to secure it in place relative to the tendon 152. In order to install the mechanical anchor, a hole 156 is drilled in a rock face 158, typically in a hanging wall in a mine. The tendon 152 is then inserted into the hole 156 and the operatively inner end of the tendon 52 is secured in the hole in a conventional manner e.g. mechanically, chemically, a combination of the two or in any other known manner. With the tendon 152 secured in position in the hole, the seal assembly 130 is positioned such that the seal formations 120 are arranged around the tendon 152 within the hole 156. Further, the operatively outer end of the tendon 152 protrudes from the hole 156. A bearing plate or washer 162 is positioned over the protruding end portion of the tendon 152 in abutment with the rock face 158 surrounding the mouth of the hole 156. A grout filler pipe 164 and a breather pipe 166 extend through the bearing plate 162 into the hole 156 between the seal elements 116 of the grout seals 130 into the portion of the hole 156 which is positioned inwardly of the seal formations 120. The tendon 152 of the mechanical anchor 150 is then pre-tensioned and secured in its pre- tensioned condition by means of a barrel and wedge or nut arrangement, generally indicated by reference numeral 170 in a conventional manner. A flowable and settable grout is then pumped into the hole through the filler pipe 164 and air which is displaced from the hole by the grout escapes through the breather pipe 166. The seal elements 116 which are arranged around the tendon 152 intermesh with one another and effectively form a seal to inhibit the grout which is pumped into the hole from flowing outwardly past the seal assembly 130. It will be appreciated, that an amount of liquid may pass between the seal elements 116, however particulate material is mostly retained by the seal elements. As the volume of particulate material, which is retained increases, it serves as a plug effectively retaining the grout within the hole 156. Any water seepage which does pass through the seal elements 116 tends to accelerate the drying and curing of the grout. As can be seen in Figures 14 to 20, another embodiment of the invention comprises a sealing member 200 having a base 202 and sealing elements 216 protruding radially from the base 202. The base 202 can be in various lengths as can be seen when comparing Figure 14 with Figure 16. The sealing elements 216 are pliable and can be bent as illustrated in Figure 17. In use, as shown in Figures 18 to 20, sealing members 200 are configured around the components of the Mechanical anchor system, including the cable/tendon 1 to be anchored, a filler pipe 202 and a breather pipe 203. This embodiment of the invention functions similarly to that of the first embodiment of the invention where the filler or inlet pipe 202 functions to pump a settable liquid such as grout into the hole 205 and air is allowed to escape from the hole through the breather or outlet pipe 203. Upon inserting the mechanical anchor 210 into the hole 205, the sealing elements 216 of the sealing member 200 fold downward and intermesh with the sealing elements 216 of the other sealing members 200. As can be seen in Figure 19 the sealing elements 216 occupy most of the space between the tendon 201, the filler pipe 202 and the breather pipe 203. Once the mechanical anchor 210 is inserted into the hole 205, grout 207 will be pumped through the filler pipe 202. The grout 207 will infiltrate the space between the sealing elements 216 and will set within the confines of the sealing elements 216. This will impede the flow of further grout 207 past the proximal end of the mechanical anchor 210. The Inventors believe that a grout seal in accordance with the invention will provide a reliable and cost-effective manner for sealing a hole and facilitating the loading of grout into the hole in a reliable and productive fashion. It is, of course, to be appreciated that the sealing system for use with a mechanical anchor in accordance with the invention is not limited to the precise constructional and functional details as hereinbefore described with reference to the accompanying drawings and which may be varied as desired. Although only certain embodiments of the invention have been described herein, it will be understood by any person skilled in the art that other modifications, variations, and possibilities of the invention are possible. Such modifications, variations and possibilities are therefore to be considered as falling within the spirit and scope of the invention and hence form part of the invention as herein described and/or exemplified. It is further to be understood that the examples are provided for illustrating the invention further and to assist a person skilled in the art with understanding the invention and is not meant to be construed as unduly limiting the reasonable scope of the invention. The inventor believes that the invention will provide a solution to sealing and securing a mechanical anchor in a rock face or wall without concern for the object to break loose or become unsecure from where it was fixed in the hole which is also time and cost efficient. CLAIMS 1. A sealing system for a mechanical anchor comprising: a first pipe for discharging a settable liquid; a second pipe, through which a fluid can be displaced; and a retainer device for locating a tendon of a mechanical anchor, the first pipe and the second pipe; and a sealing means associated with the retainer device located between a proximal and a distal end of the tendon, wherein the sealing means expands into the hole and the surrounding cavities of the hole in which the tendon is to be anchored, the settable liquid being pumped through