Mine support grout packs

Abstract

A grout pack is provided comprising a grout bag and a restraining envelope encircling the grout bag. The restraining envelope includes multiple elongate tension elements made of a multitude of fibres twisted, braided or woven to form confinement tension elements for operatively supporting the grout bag. The restraining envelope may include an inner mesh layer positioned on the inside of the elongate tension elements which may assume the form of containment rings encircling the grout bag at spaced positions up the height of the grout pack. Alternatively, or in addition, at least some elongate tension elements may extend in generally helical directions of opposite hand in the installed condition of the grout pack. The tension element may assume the form of a rope or a length of webbing. The ends of the rope or webbing may be joined in a manner providing for controlled slipping of overlapping ends thereof.

1 . A grout pack comprising a grout bag and a restraining envelope encircling the grout bag, the grout bag having flexible side walls and two ends defining, in use, a top, and a bottom and a cavity for receiving settable granular material or grout, the grout bag further having an inlet for slurry to be introduced into the interior of the grout bag and wherein the flexible side walls are adapted to retain solids within the grout bag and the grout bag has an axis in the general direction of which a filled and set grout pack is adapted to yield, wherein the restraining envelope includes multiple elongate tension elements each of which is made of a multitude of fibres twisted, braided or woven or any combination thereof to form confinement tension elements for operatively supporting the grout bag. 
     
     
         2 . A grout pack as claimed in  claim 1  in which the fibres are polymer fibres selected from one or more of polypropylene, nylon, polyesters, polyethylene and aromatic polyamides. 
     
     
         3 . A grout pack as claimed in  claim 1  in which the restraining envelope includes an inner mesh layer positioned on the inside of the elongate tension elements. 
     
     
         4 . A grout pack as claimed in  claim 1  in which at least some elongate tension elements assume the form of containment rings encircling the grout bag at spaced positions up the height of the grout pack in the installed condition. 
     
     
         5 . A grout pack as claimed in  claim 1  in which at least some elongate tension elements extend in generally helical directions of opposite hand in the installed condition of the grout pack. 
     
     
         6 . A grout pack as claimed in  claim 1  in which the restraining envelope includes terminal rigid confinement rings at each of its two ends. 
     
     
         7 . A grout pack as claimed in  claim 1  in which a tension element assumes the form of a rope ( 8 ,  10 ). 
     
     
         8 . A grout pack as claimed in  claim 7  in which the ends of a length of rope are spliced together to form an endless loop. 
     
     
         9 . A grout pack as claimed in  claim 8  in which the splice is configured to be either a non-slip type of splice or a splice configured to slip under predetermined loads in order to provide for controlled yielding of an installed grout pack. 
     
     
         10 . A grout pack as claimed in  claim 1  in which a tension element assumes the form of a length of webbing. 
     
     
         11 . A grout pack as claimed in  claim 10  in which the free ends of a length of webbing are associated with a buckle that is arranged to provide for yielding under predetermined loads. 
     
     
         12 . A grout pack as claimed in  claim 10  in which selected overlapping zones of the webbing are stitched together. 
     
     
         13 . A restraining envelope adapted to receive a grout bag in order to form a grout pack as claimed in  claim 1 .