AU2006202538B2

AU2006202538B2 - Grout pack restraining system

Info

Publication number: AU2006202538B2
Application number: AU2006202538A
Authority: AU
Inventors: Nils Mittet Skarbovig
Original assignee: Norsenet Pty Ltd
Current assignee: Norsenet Pty Ltd
Priority date: 2006-06-15
Filing date: 2006-06-15
Publication date: 2012-07-19
Anticipated expiration: 2026-06-15
Also published as: AU2006202538A1

Abstract

The invention provides a grout pack restraining system which includes a plurality of elongate elements shaped to extend about a grout pack and which are characterised in that they are configured to control circumferential expansion of the grout pack beyond the expansion permitted through material yield of the elements. In one embodiment the rings of different diameter are secured about the grout pack. In a further embodiment rings which are configured to be circumferentially expandable are secured about the grout pack.

Description

AUSTRALIA Patents Act COMPLETE SPECIFICATION (ORIGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Norsenet (Pty) Limited Actual Inventor(s): Nils Mittet Skarbovig Address for Service and Correspondence: PHILLIPS ORMONDE & FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: GROUT PACK STRAINING SYSTEM Our Ref: 775407 POF Code: 470431/478084 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6006q 2 GROUT PACK RESTRAINING SYSTEM 5 FIELD OF THE INVENTION This invention relates to a grout pack restraining system, more particularly to a restraining system for a yielding grout pack. 10 BACKGROUND TO THE INVENTION A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission or a suggestion that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. 15 The support of the hanging wall in mining stopes is one of the most basic requirements in mining. Dependent on the type and quality of rock being supported, the depth of mining, the prevalent field stresses, seismicity, stoping width and a number of other factors, stope support can vary across a vast 20 range of materials, configurations and systems. These include, among others, gum poles, timber and composite packs, steel props, backfill paddocks, unmined ore pillars, hanging wall rock anchors and any combination of the above. 25 Grout packs are among the increasingly utilized combination support products consisting essentially of a support column formed by a geotextile bag holding cured cemented backfill or a similar cured cementious grout that is resistant to compression. The geotextile bag is usually protected and supported against 3 lateral dilation of the pack under load by a wire or polymer mesh, as well as a set of additional wire or polymer rings surrounding the bag and mesh horizontally. The grout column is usually combined with timber poles that are required to suspend the bag, net and ring assembly prior to filling with grout. For the purpose of this background discussion, the structural and support contribution of the timber poles to the behaviour and performance of the grout pack shall be disregarded. Under vertical (axial) load the grout column reduces in length and dilates laterally according to the Poisson's ratio of the grout material. Besides the cohesion of the cemented material, the geotextile bag (a), the surrounding mesh (b), as well as the restraining rings (c) all contribute in some measure to the support resistance of the pack in that they restrain the lateral dilation of the grout column. (a) The geotextile material is usually woven or knitted from low tenacity polymer fibres and offers little lateral confinement as it stretches easily under load. Although it will provide some useful confinement, its primary function is to provide suitable containment for the grout slurry with optimal drainage and filtering properties. (b) The secondary mesh basically forms a support structure for the geotextile material, preventing excessive bulging (with the associated increased solids losses through the enlarged pores) under hydrostatic loading of the uncured grout slurry. To add some degree of yieldability to the cured pack, the netting wires (or fibres) are usually oriented at 450 to the axis of the pack allowing the mesh to stretch in the horizontal direction, providing some additional lateral confinement to the pack. (c) The lateral restraining rings are the major structural confinement of the pack and their strengths contribute directly and significantly to the support resistance of the pack. In conventional grout packs the performance of these rings is essentially dependent on their material properties, characterised primarily by their tensile strength and elongation. Invariably there is a trade-off in terms of 4 these properties in that higher tensile strength generally goes with lower elongation and vice versa. In stope support the stiffness of a support unit has to be carefully considered, however, as stronger and stiffer is not necessarily better, particularly in seismic stress environments where, under dynamic loading, shear stresses in the hanging wall around a very stiff pack can exceed the strength of the rock resulting in hanging wall failure ("punching"). Under such conditions, a yielding support unit should be able to absorb large and/or sudden rock movement without losing its structural integrity. Similarly, high closure stopes also require yieldability to safely absorb the energy of the closing hanging wall. In conventional grout packs, the width-to-height ratio of the grout columns is insufficient to generate their own cemented material confinement under compression and the simple tendon lateral restraining rings, as described in (c) above are, therefore, the only significant lateral confinement of these packs. It is these rings that largely control the compression behaviour of the packs. At present, however, they do not permit adequate yielding of the packs from an unyielded initial condition to a fully yielded condition as they rely solely on material deformation to permit yielding. Yield is thus determined by the quality of the steel used for the elements. After expansion permitted by the material yield of the elements the elements break and expansion becomes uncontrolled. In this specification, yield refers to two separate concepts: a) yield or elongation as a material property is the deformation of a material (e.g., a metal) beyond its elastic limit; i.e. yield or elongation is irrecoverable plastic deformation; b) yield as a structural property refers to the plastic deformation of a structure, e.g., a grout pack; an "unyielded condition" refers to the condition of the grout pack immediately after being filled and a "fully yielded condition" refers to the condition of the grout pack after being 5 subjected to axial loading wherein the diameter thereof increases according to the Poisson's ration of the material of which the structure is composed. 5 Therefore, in light of the above, it would be desirable to provide a grout pack restraining system which will at least partially alleviate the abovementioned drawbacks. SUMMARY OF THE INVENTION 10 According to one aspect of the invention there is provided a grout pack restraining system which includes a plurality of elongate elements shaped to extend about a grout pack having an initial size and characterised in that the elements are configured to control circumferential expansion of the grout pack beyond the expansion permitted through material yield of the elements, the elongate elements including: 15 (a) a first ring having a first diameter in an unyielded condition, the first diameter sized to restrain the grout pack at its initial size, and a second diameter at a maximum design yield, the second diameter being significantly greater than the first diameter; and (b) a second ring supported relative to the first ring; 20 (c) wherein the second ring has, in an unyielded condition, a third diameter which is significantly greater than the first diameter and substantially equal to or less than the second diameter, such that, in response to expansion of the grout pack which causes yielding of the first ring, the second ring will provide restraint to the grout pack prior to failure of the first ring, thereby providing a 25 progressive yield of the grout pack. 30 CpofPwd\SPEC-77 [4d7 4ocx 6 Further features of the invention provide for the rings to have a helical configuration; alternatively for the rings to be concentric, and for the rings of the second ring to be secured to the fist ring by means of ties. 5 A further aspect of the present invention provides an element for a grout pack restraining system, the element being shaped to extend about a grout pack C:w o PEC-7754071] .do 7 having an initial size to control circumferential expansion of the grout, the element having: (a) a first ring having a first diameter in an unyielded condition, the first diameter sized to restrain the grout pack at its initial size, and a 5 second diameter at a maximum design yield, the second diameter being significantly greater than the first diameter; and (b) a second ring supported relative to the first ring; (c) wherein the second ring has, in an unyielded condition, a third diameter which is significantly greater than the first diameter and 10 substantially equal to or less than the second diameter, such that, in response to expansion of the grout pack the first ring restrains the grout pack as it yields from its unyielded condition to its maximum design yield condition and the second ring provides restraint to the grout pack prior to failure of the first ring, thereby providing a progressive yield of the grout 15 pack. Further features of the invention may provide for the second ring to be connected to the first ring by means of ties, the rings may be concentric or the first ring and the second ring are secured together using at least one helically 20 extending elongate element. Yet another aspect of the present invention provides a method of restraining a grout pack which includes the steps of: (a) providing a plurality of elongate elements having: 25 (i) a first ring having a first diameter in an unyielded condition, the first diameter sized to restrain the grout pack at its initial size, and a second diameter at a maximum design yield, the second diameter being significantly greater than the first diameter; and (ii) a second ring supported relative to the first ring and having, in 30 an unyielded condition, a third diameter which is significantly greater than the first diameter and substantially equal to or less than the second diameter, such that, in response to expansion of the grout pack which <Sename> 7a causes yielding of the first ring, the second ring will provide restraint to the grout pack prior to failure of the first ring; and (b) securing the plurality of elongate elements about the grout pack to control circumferential expansion and provide a progressive yield of the 5 grout pack. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described, by way of example only, with reference to the accompanying drawings in which: 10 Figure 1 is a top plan view of a first embodiment of a grout pack restraining system; Figure 2 is an isometric view of part of the grout pack restraining system in Figure 1; 15 8 Figure 3 is a side elevation of a fastener used in the grout pack restraining system in Figure 1; Figure 4 is a front elevation of the fastener in Figure 3; Figure 5 is a further side elevation of the fastener in Figure 3; Figure 6 is a side elevation of the grout pack restraining system in Figure 1 in use; Figure 7 is a side elevation of the grout pack restraining system in Figure 1 in use; Figure 8 is a side elevation of a fastener used in the grout pack restraining system in Figure 1 in an alternate arrangement; Figure 9 is a side elevation of second embodiments of a fastener for use in a grout pack restraining system; Figure 10 is a side elevation of third embodiments of a fastener for use in a grout pack restraining system; Figure 11 is a side elevation of fourth embodiments of a fastener for use in a grout pack restraining system; Figure 12 is a top plan view of a second embodiment of a grout pack restraining system; Figure 13 is a top plan view of a third embodiment of a grout pack restraining system; 9 Figure 14 is a isometric view of part of the grout pack restraining system in Figure 13; Figure 15 is a top plan view of a fourth embodiment of a grout pack restraining system; Figure 16 is a sectional end view of part of the grout pack restraining system in Figure 15; Figures 17 to 19 are side elevations of part of the grout pack restraining system in Figure 15 moving from an unyielded to a fully yielded condition; Figure 20 is a top plan view of the grout pack restraining system in Figure 15 in a fully yielded condition; Figure 21 is a side elevation of the grout pack restraining system in Figure 15 in use; Figure 22 is a side elevation of the grout pack restraining system in Figure 15 in use in a second configuration; Figure 23 is a side elevation of the grout pack restraining system in Figure 15 in use in a third configuration; Figure 24 is a top plan view of a fifth embodiment of a grout pack restraining system; Figure 25 is a isometric view of part of the grout pack restraining system in Figure 24; 10 Figure 26 is a top plan view of a sixth embodiment of a grout pack restraining system; Figure 27 is a isometric view of part of the grout pack restraining system in Figure 26; Figure 28 is a part sectional side elevation of an alternate collar for use in the grout pack restraining system in Figure 15; Figure 29 shows side elevations of the collars in Figure 29 in use moving from an unyielded to a fully yielded condition; Figure 30 is a side elevation of an elongate element for use in a seventh embodiment of a grout pack restraining system; Figure 31 is a side elevation of part of the elongate element in Figure 30 moving from an unyielded to a fully yielded condition; Figure 32 is a top plan view of a seventh embodiment of a grout pack restraining system; Figure 33 is a side elevation of part of the grout pack restraining system in Figure 32; Figure 34 is a side elevation of the grout pack restraining system in Figure 32 in use; Figure 35 is a side elevation of the grout pack restraining system in Figure 32 in use in a second configuration; 11 Figure 36 is a side elevation of the grout pack restraining system in Figure 32 in use in a third configuration; Figure 37 is a side elevation of the grout pack restraining system in Figure 32 in use in a fourth configuration; Figure 38 is a side elevation of the grout pack restraining system in Figure 32 in use in a fifth configuration; Figure 39 is a side elevation of an elongate element for use in an eighth embodiment of a grout pack restraining system; Figure 40 is a top plan view of an eighth embodiment of a grout pack restraining system; Figure 41 side elevation of part of the grout pack restraining system in Figure 41; and Figure 42 is a side elevation of an elongate element for use in a ninth embodiment of a grout pack restraining system. DETAILED DESCRIPTION OF THE DRAWINGS A first embodiment of a grout pack restraining system (1) is shown in Figures 1 and 2 and includes a pair of rings (2,3) each made from a steel rod with its ends welded together. The rings (2,3) have a first diameter and second diameter respectively, with the first diameter being smaller than the second diameter. The rings (2,3) are concentrically arranged and secured to each other by a number of ties (5) spaced about the circumferences thereof. As shown in Figures 12 3 to 5, each tie (5) has a sleeve (6) moulded from a plastics material which is a sliding fit over the ring (2) and from which extends an integral flexible strap (7). The distal end (8) of the strap (7) is slightly narrower than the remainder thereof and has a series of teeth (9) on one side thereof. The end (8) can be fed through a slot (10) with a detent (not shown) therein centrally located on the strap. This permits the end (8) to be fastened about the ring (3) in the manner of a conventional cable tie with the rings (2,3) coaxial to each other. In use, as shown in Figure 6, a number of rings (2a to 2d) are secured over a grout pack (15) spaced along the length thereof and with the rings (3a to 3d) suspended therefrom. The diameter of the rings (2a to 2d) is selected to provide a tight fit over the grout pack and provide restraint in its unyielded condition. Figure 7 shows the grout pack (15) as it progressively yields under pressure from movement of the hanging wall (20) towards the foot wall (21). Here, "closure" indicates the degree of movement of the hanging wall (20) towards the foot wall (21) from the time at which the grout pack (15) is installed in position. Also, in this figure, only three ring sets (2a, 2c, 2e, 3a, 3c, 3e) are shown. It has been found in practice that grout packs yield by expanding and disintegrating from the top (23) downwards, as depicted. As this occurs, the grout pack gradually expands to engage the rings (3a to 3e) whilst still being restrained by the rings (2a to 2e). At approximately 20% closure the ring (2a) has yielded approximately 35% whilst the ring (3a) is tightly constricted about the grout pack (15). As expansion occurs down the length of the grout pack (15) the rings (2c, 23) similarly yield whilst the rings (3c, 3e) provide restraint. At 30% closure, the ring (2a) is fully yielded, showing its maximum design yield of about 40%, whilst the ring (3a) restrains the grout pack (15) and continues yielding. The performance of the ring (2a) is assisted by the ring (3a). At 30% closure, ring (2e) is relatively undistorted with ring (3e) only commencing to restrain the grout pack (15).

13 The grout pack restraining system thus permits controlled circumferential expansion of the grout pack between the unyielded condition and fully yield condition. This is in major part through configuring the system to permit circumferential expansion of the grout pack beyond the expansion which would occur through simple yield of the material used in the system, in this embodiment by the provision of the rings of the second larger diameter. It will be appreciated, however, that many other embodiments of a grout pack restraining system exists which fall within the scope of the invention, particularly as regards the material used for the rings and the cross-sectional shape thereof. Also, the rings can be secured in any convenient configuration and, as shown in Figure 8, the ring (2b), adjacent ring (3a), can be suspended from the ring (3a) using a tie (5b). Also, ties of any suitable configuration can be used. As shown in Figures 9 and 10, ties (30, 32), could include an elongate body (34, 35) with hook formations (36, 37) at either end thereof in which the rings (2a, 3a) can be secured. As also illustrated in these figures, each body (34, 35) can have an arm (34a, 35a) extending laterally therefrom having a hook (36a, 37a) at the end thereof for securing a further ring (2b). Further alternatively, as shown in Figure 11, the ties (40, 41, 42) can simply be elongate bodies having apertures at either end thereof through which the rings (2a, 3a) can be inserted. More than two rings of increasing diameter can also be used and it is not necessary for the rings to be co-axial. As shown in Figure 12, three rings (50, 51, 52) of different diameter can be used and these can be secured together at a single point (54) by welding or by using a fastener. Further alternatively, a pair of rings (60, 61) of first and second diameter, can be secured together using a pair of helically extending elongate elements (63, 64).

14 This helical configuration in effect provides several restraining rings of increasing diameter and provides a much smoother transition of restraining duty from the ring of smaller diameter (60) to that of larger diameter (61). It is, however, not necessary to use rings of different diameter to control expansion of a grout pack. Instead, a ring can be provided which can be increased in diameter through a predetermined radial force by virtue of its configuration rather than through material deformation of the material of the ring. As shown in Figures 15 to 17, a ring (70) providing part of a grout pack restraining system is formed from an elongate steel element (72) with the ends thereof (73, 74) overlapping. A collar (76, 77), in this embodiment a ferrule, is secured over the overlapping sections at each end (73, 74). The ferrules (76, 77) are swaged onto the overlapping ends (73, 74) to permit relative movement of these. The swaging force determines the frictional resistance to movement. The ends (73, 74) are bent outwardly to prevent them from pulling through the ferrules (76, 77). Under predetermined internal force on the ring (70) its diameter increases through frictional yield between the overlapping ends (73, 74) as shown in Figures 17 to 19. In the fully yielded condition, shown in Figures 19 and 20, the ferrules (76, 77) abut preventing further relative outward movement of the ends (73, 74) and hereafter the ring (70) yields through material deformation. In use, as shown in Figure 21, a plurality of rings (70a to 70g) are secured about a grout pack (15) spaced along the length thereof. As described with reference to Figure 7, closure of the hanging wall (20) and foot wall (21) causes compression and a deformation of the grout pack (15). The rings (70a to 70g) control the circumferential expansion of the grout pack (15) initially through frictional resistance and thereafter by material deformation until fully yielded as described above.

15 Any suitable configuration of rings (70a to 70g) can be used. As illustrated in Figure 22, the ring (70a to 70f) can be positioned adjacent the upper end (23) of the grout pack (15) to control expansion there. It is, however, not necessary to secure the rings (70) coaxilly with the grout pack (15). As shown in Figure 23, the rings could be secured elliptically about the grout pack to form a type of net jacket, and these could be interspersed with non-yielding rings of conventional construction. Frictional expansion of the ring can also be achieved through other configurations. As illustrated in Figures 24 and 25, an elongate element (80) can be folded into a pair of overlapping rings (81, 82) with the diameter of the first ring (81) being of smaller diameter than that of the second ring (82) and of the desired initial restraining diameter in an unyielded condition. A ferrule (83) joins the overlapping portion of the elongate element (80) and provides frictional resistance to circumferential expansion of the ring (81). It will be understood that expansion of the ring (81) causes similar contraction of the ring (82) and at the point where the rings (81, 82) have equal diameter, both will undergo material deformation under continued expansion of a grout pack over which they are secured. It will also be understood that the ring (81) could be formed with the ends of the elongate element (80) overlapping as described with reference to Figures 15 to 17 to provide further frictional expansion of this ring. With such a configuration it may be desirable to secure the overlapping portion of the elongate element together to prevent relative movement. This will provide a grout pack restraining system which combines the characteristics of the system described with reference to Figures 1 and 2 with that of the system described with reference to Figures 15 to 17. Further alternatively, as shown in Figures 26 and 27, a pair of rings (90, 91) of equal diameter can be secured together by a contiguous helical member (93) 16 which provides different yield characteristics because of its length and also provides friction against the expanding grout pack. Furthermore, any suitable means of providing frictional resistance between overlapping ends of a ring can be used. As illustrated in Figure 28, a chain link (100, 101) can be welded to each end (73, 74) inclined to the axis of the elongate element and over the overlapping ends. Under relative movement of the ends, the chain links (100, 101) cause the ends moving relative to them to be deformed under tensile load and this deformation together with the accompanying friction provides the required yield resistance. The sequential expansion of the overlapping ends is shown in Figure 29 and is similar to that illustrated in Figures 17 to 19. Resistance to expansion can also be achieved through use of a non-linear elongate element (110) as illustrated in Figure 30. Here, an elongate steel element is formed with a series of undulations (112) along its length. As illustrated in Figure 31, the overall length of the element (110) is increased when the ends thereof are forced in opposite directions and the undulations reduce in magnitude until the element is linear. The increase in length for each undulation is indicated in Figure 31 by "x". A ring (120) formed from the elongate element (110) is shown in Figures 32 and 33 and is formed with the undulations extending in the axial direction. It will be understood that applying an internal radial force to the ring will cause an increase in diameter thereof against the resistance provided by the undulations to straightening. Rings (120a to 120g) are shown in use over a grout pack (15) in Figure 34. Similarly to the restraining systems illustrated with reference to Figures 7 and 21, the rings (120a to 120g) are secured over the grout pack spaced along the length thereof. The closure of the hanging wall (20) and foot wall (21) causes deformation of the grout pack (15) as previously discussed and this is controlled by the rings (120a to 120g) as illustrated in Figure 34.

17 It will be appreciated that the rings (120a to 120g) can be paired in a meshed configuration as illustrated in Figure 35. Alternatively, as shown in Figure 36, rings (120a to 120e) could be used together with non-expanding rings (130a, 130b) located co-axially about the grout pack (15) or in an elliptical configuration as shown in Figure 37. The rings (120a, 120b) could also be used with rings (70a to 70e) of the type described in Figures 15 to 17 as shown in Figure 38. The degree of expansion can be controlled by the number of undulations in the elongate element. As shown in Figures 39 to 41, a single undulation (130) can be provided in the elongate element (131) to provide a ring (32) which provides only a small degree of circumferential expansion. Also, as shown in Figure 42, loops (140) can be provided in the elongate element (141) instead of undulations to permit expansion thereof. The grout pack retraining system of the invention thus provides a simple yet highly effective means to control circumferential expansion of a grout pack between an unyielded condition and a fully yielded condition. The elongate elements of the system are configured to permit expansion of the grout pack about which they are secured greater than the expansion permitted by simple material deformation of the elements. Many other embodiments which fall within the scope of the invention will be apparent to a person skilled in the art.

Claims

1. A grout pack restraining system which includes a plurality of elongate elements shaped to extend about a grout pack having an initial size to control 5 circumferential expansion of the grout pack, the elongate elements including: (a) a first ring having a first diameter in an unyielded condition, the first diameter sized to restrain the grout pack at its initial size, and a second diameter at a maximum design yield, the second diameter being significantly 10 greater than the first diameter; and (b) a second ring supported relative to the first ring; (c) wherein the second ring has, in an unyielded condition, a third diameter 15 which is significantly greater than the first diameter and substantially equal to or less than the second diameter, such that, in response to expansion of the grout pack which causes yielding of the first ring, the second ring will provide restraint to the grout pack prior to failure of the first ring, thereby providing a progressive yield of the grout pack. !0

2. The grout pack restraining system as claimed in claim 1 in which the second ring is connected to the first ring by means of ties.

3. The grout pack restraining system as claimed in claim 1 in which the rings are 25 concentric.

4. The grout pack restraining system as claimed in claim 2 in which the rings have a helical configuration. 30

5. An element for a grout pack restraining system, the element being shaped to extend about a grout pack having an initial size to control circumferential expansion of the grout, the element having: 19 (a) a first ring having a first diameter in an unyielded condition, the first diameter sized to restrain the grout pack at its initial size, and a second diameter at a maximum design yield, the second diameter being significantly greater than the first diameter; and 5 (b) a second ring supported relative to the first ring; (c) wherein the second ring has, in an unyielded condition, a third diameter which is significantly greater than the first diameter and substantially equal to 10 or less than the second diameter, such that, in response to expansion of the grout pack the first ring restrains the grout pack as it yields from its unyielded condition to its maximum design yield condition and the second ring provides restraint to the grout pack prior to failure of the first ring, thereby providing a progressive yield of the grout pack. 15

6. The element as claimed in claim 5 in which the second ring is connected to the first ring by means of ties.

7. The element as claimed in claim 5 in which the rings are concentric. 20

8. The element as claimed in claim 5 in which the first ring and the second ring are secured together using at least one helically extending elongate element.

9. A method of restraining a grout pack which includes the steps of: 25 (a) providing a plurality of elongate elements having: (i) a first ring having a first diameter in an unyielded condition, the first diameter sized to restrain the grout pack at its initial size, and a second diameter at a maximum design yield, the second diameter being significantly 30 greater than the first diameter; and (ii) a second ring supported relative to the first ring and having, in an unyielded condition, a third diameter which is significantly greater than the first diameter and substantially equal to or less than the second diameter, such that, in response to expansion of the grout pack which causes yielding of the Oft-n~, 20 first ring, the second ring will provide restraint to the grout pack prior to failure of the first ring; and (b) securing the plurality of elongate elements about the grout pack to 5 control circumferential expansion and provide a progressive yield of the grout pack.

10. A grout pack restraining system according to any one of claims to 1 to 4 substantially as herein described with reference to the accompanying 10 drawings.

11. An element for a grout pack restraining system according to any one of the embodiments substantially as herein described with reference to the accompanying drawings. 15

12. A method of restraining a grout pack according to any one of the embodiments substantially as herein described with reference to the accompanying drawings.