Rock bolt with grout flow geometry

Abstract

A rock bolt having a modified tip geometry for spreading grouting material along the bolt or rupturing a grouting material container, or both, and method of using such a rock bolt for substrate support.

1 . A substrate reinforcement device, comprising: a bolt having a tip comprising a geometry configured to transport grouting materials from the tip, along a length of the bolt.  
     
     
         2 . The substrate reinforcement device of  claim 1 , wherein the geometry of the tip promotes mixing of the grouting materials.  
     
     
         3 . The substrate reinforcement device of  claim 1 , wherein the geometry of the tip promotes flow of the grouting materials around the tip.  
     
     
         4 . The substrate reinforcement device of  claim 1 , wherein the geometry of the tip promotes flow of the grouting material through an annulus formed between the bolt and a wall of a pilot hole.  
     
     
         5 . The substrate reinforcement device of  claim 1 , wherein the geometry comprises an auger shape.  
     
     
         6 . The substrate reinforcement device of  claim 5 , wherein the auger shape is configured in shape and pitch relative to a diameter of the bolt, a pilot hole diameter, a viscosity of the grouting materials, a bolt insertion rate relative to the pilot hole, and a bolt rotation rate relative to the pilot hole.  
     
     
         7 . The substrate reinforcement device of  claim 1 , wherein the geometry is further configured to rupture a grouting materials container residing in a pilot hole.  
     
     
         8 . The substrate reinforcement device of  claim 7 , wherein the geometry comprises an extreme tip having a smaller surface area than a cross section of the bolt.  
     
     
         9 . The substrate reinforcement device of  claim 1 , wherein the geometry is further configured to create a groove in a pilot hole wall.  
     
     
         10 . The substrate reinforcement device of  claim 9 , wherein the geometry comprises a protrusion to create a groove in the pilot hole wall.  
     
     
         11 . A substrate reinforcement device, comprising: 
 a bolt having a tip comprising a geometry configured for rupturing a grouting materials container residing in a pilot hole.    
     
     
         12 . The substrate reinforcement device of  claim 11 , wherein the geometry comprises a chisel shape.  
     
     
         13 . The substrate reinforcement device of  claim 11 , wherein the geometry comprises a plurality of piercing features.  
     
     
         14 . The substrate reinforcement device of  claim 11 , wherein the geometry promotes rapid release of a grouting material within the container upon contact with the container.  
     
     
         15 . The substrate reinforcement device of  claim 11 , wherein the geometry of the tip promotes rapid release of a grouting material within the container upon rotational contact with the container.  
     
     
         16 . A rock bolt, comprising: 
 a shaft comprising a tip end, the tip end comprising at least one feature selected from the group consisting of an auger shape, and an extreme tip having a smaller surface area than a cross section of the shaft.    
     
     
         17 . A method of stabilizing a substrate, comprising: 
 providing a pilot hole in a substrate;    providing a grouting material within the pilot hole;    inserting a bolt into the pilot hole and into the grouting material, the bolt having a tip with a geometry configured to transport grouting materials from the tip, along a length of the bolt.    
     
     
         18 . The method of  claim 17 , wherein the tip comprises at least one auger shape for the transport of grouting materials.  
     
     
         19 . The method of  claim 18 , further comprising inserting the bolt into the pilot hole at an insertion rate and at the same time rotating the bolt at a rotation rate, wherein the auger shape is configured in shape and pitch relative to a diameter of the bolt, a pilot hole diameter, a viscosity of the grouting materials, the bolt insertion rate, and the bolt rotation rate.  
     
     
         20 . A method of stabilizing a substrate, comprising: 
 providing a pilot hole in a substrate;    providing a grouting material within the pilot hole, the grouting material being within a container;    inserting a bolt into the pilot hole and into the grouting material, the bolt having a tip with a geometry configured to rupture the container for the release of the grouting material.    
     
     
         21 . The method of  claim 20 , further comprising rotating the bolt during the inserting.