Friction rock stabilizers

Abstract

Friction rock stabilizers such as for example roof anchors, comprising a erally annular body which from end-to-end has a slot through its thickness and is circumferentially compressible for installation into a bore of diameter substantially smaller than the normal outer diameter of the body whereby, after such installation, the resilience of the body causes the body outer periphery to anchor by frictional engagement with the surrounding wall of the bore. Also, an anchoring method employing a stabilizer of this type.

I claim: 
     
       1. A friction stabilizer for insertion in a bore in a structure such as a roof or side wall of a mine shaft or other underground opening for anchoring the structure, said stabilizer comprising a generally annular body from end-to-end having a slot through its thickness, said body including edge portions extending along opposite sides of said slot and relatively arranged to permit substantial circumferential compression of said body, said body being of outer diameter predetermined to be substantially larger than the diameter of the bore in which it is to be inserted such that insertion of said body in such bore causes substantial circumferential compression of said body, said body being dimensioned to be plastically deformed during its insertion in such bore, the stabilizer being free of structure precluding said substantial compression and plastic deformation of said body during its said insertion, said body being of material permitting its said substantial compression and plastic deformation during its said insertion and, after such insertion, causing the body outer periphery to frictionally engage the surrounding wall of the bore for frictionally anchoring the structure, the ratio of the length of said body to the outer diameter thereof being at least about 16 to 1, the ratio of the radial thickness of said body to the outer diameter thereof being at a maximum about 1 to 5 and at a minimum about 1 to 50, and the outer circumferential dimension of said body being at least two inches. 
     
     
       2. A friction stabilizer according to claim 1, wherein the circumferential width of said slot is at a maximum about 25 percent of the outer circumferential dimension of said body. 
     
     
       3. A friction stabilizer according to claim 1, wherein the outer periphery of said body is at least substantially imperforate. 
     
     
       4. A friction stabilizer according to claim 1, wherein said slot is straight from end-to-end of said body. 
     
     
       5. A friction stabilizer according to claim 1, wherein the interior of said body is open. 
     
     
       6. A friction stabilizer according to claim 1, further comprising means for tensioning said body after its insertion in a bore. 
     
     
       7. A friction stabilizer according to claim 1, further comprising wedge means movable internally of an end of said body. .Iadd. 
     
     
       8.  A friction stabilizer for insertion in a bore in a structure such as a roof or side wall of a mine shaft or other underground opening for anchoring the structure, said stabilizer comprising when inserted a generally annular body arranged to permit when inserted substantial circumferential compression of said body against the surrounding wall of the bore, said body being of substantially the same transverse dimension along substantially its full length, said body being of outer diameter predetermined to be substantially larger than the diameter of the bore in which it is to be inserted such that insertion of said body in such bore causes substantial circumferential compression of said body, said body being dimensioned to be plastically deformed during its insertion in such bore, the stabilizer being free of structure precluding such substantial compression and plastic deformation of said body during its said insertion, said body being of material permitting its said substantial circumferential compression and transverse plastic deformation after said insertion in the event of a shift of said structure in a plane transverse to the length of said stabilizer, and, after such insertion, causing the body outer periphery to frictionally engage the surrounding wall of the bore for frictionally anchoring the structure, the ratio of the length of said body to the outer diameter thereof being at least about 16 to 1, the ratio of the radial thickness of said body to the outer diameter thereof being at a maximum about 1 to 5 and at a minimum about 1 to 50, and the outer circumferential dimension of said body being at least two inches. .Iaddend. .Iadd. 
     
     
       9.  A friction stabilizer, according to claim 8, wherein: said material comprises means plastically responsive to diverse, radial-component forces applied to said body, as by a surface of said surrounding wall of the bore, substantially fully along a continuous and substantially full length of said body to effect an engagement of said body with said surrounding wall of the bore with a given, substantially uniformly distributed, anchoring force. .Iaddend. .Iadd.   
     
     
       10.  A friction stabilizer, according to claim 9, wherein: said material further comprises means which, responsive to an axial translation of said stabilizer due to strata separation of said structure or the like, causes said body to retain such engagement with substantially all said given anchoring force. .Iaddend. .Iadd.   
     
     
       11.  A friction stabilizer for insertion in a bore in a structure such as a roof or side wall of a mine shaft or other underground opening for anchoring the structure, said stabilizer comprising when inserted a generally annular body arranged to permit when inserted substantial circumferential compression of said body against the surrounding wall of the bore, said body being of substantially the same transverse dimension along substantially its full length, said body being of outer diameter predetermined to be substantially larger than the diameter of the bore in which it is to be inserted such that insertion of said body in such bore causes substantial circumferential compression of said body, said body being dimensioned to be plastically deformed during its insertion in such bore, the stabilizer being free of structure precluding such substantial compression and plastic deformation of said body during its said insertion, said body being of material permitting its said substantial circumferential compression and transverse plastic deformation after said insertion in the event of a shift of said structure in a plane transverse to the length of said stabilizer, and, after such insertion, causing the body outer periphery to frictionally engage the surrounding wall of the bore for frictionally anchoring the structure, and wherein said material comprises means plastically responsive to diverse, radial-component forces applied to said body, as by a surface of said surrounding wall of the bore, substantially fully along a continuous and substantially full length of said body to effect an engagement of said body with said surrounding wall of the bore with a given, substantially uniformly distributed, anchoring force. .Iaddend. .Iadd. 
     
     
       12.  A friction stabilizer for insertion in a bore in a structure such as a roof or side wall of a mine shaft or other underground opening for anchoring the structure, said stabilizer comprising when inserted a generally annular body arranged to permit when inserted substantial circumferential compression of said body against the surrounding wall of the bore, said body being of substantially the same transverse dimension along substantially its full length, said body being of outer diameter predetermined to be substantially larger than the diameter of the bore in which it is to be inserted such that insertion of said body in such bore causes substantial circumferential compression of said body, said body being dimensioned to be plastically deformed during its insertion in such bore, the stabilizer being free of structure precluding such substantial compression and plastic deformation of said body during its said insertion, said body being of material permitting its said substantial circumferential compression and transverse plastic deformation after said insertion in the event of a shift of said structure in a plane transverse to the length of said stabilizer, and, after such insertion, causing the body outer periphery to frictionally engage the surrounding wall of the bore for frictionally anchoring the structure, and wherein the material comprises means which, responsive to an axial translation of said stabilizer due to strata separation of said structure or the like, causes said body to retain such engagement with substantially all said given anchoring force. .Iaddend. .Iadd. 
     
     
       13.  A friction stabilizer for insertion in a bore in a structure such as a roof or side wall of a mine shaft or other underground opening for anchoring the structure, said stabilizer comprising a generally tubular body of substantially one cross-sectional configuration along substantially its full length, said body having a maximum transverse dimension predetermined to be larger than the maximum transverse dimension of the bore in which it is to be inserted, whereby insertion of said body in such bore causes circumferential compression and deformation of said body, the stabilizer being free of structure precluding such circumferential compression and deformation of said body, and said body being of material which, in response to a bore insertion of said stabilizer (a) permits both said circumferential compression of said body, and a transverse deformation thereof as well, in the event of a shift in a plane transverse to the length of said stabilizer, of a section or sections of any such bored structure in which said stabilizer shall have been inserted; (b) causes said body, to frictionally engage the wall of any such bore, thereby to anchor the bored structure, substantially fully along a continuous and substantially full length of said body, with a given, substantially uniformly distributed, anchoring force; and which also (c) maintains not less than substantially all said given anchoring force, even in the event of partial or full collapse of said body at some location therealong, in that portions of said body, defined by or subsisting opposite any such collapse, apply some proportionate anchoring forces to corresponding portions of such bore wall thereabout, whether such portions of said body are coaxially or linearly aligned with each other, or displaced or shifted therebetween by any such collapse. .Iaddend. .Iadd. 
     
     
       14.  A friction stabilizer, according to claim 13, wherein said material comprises means plastically responsive to diverse, radial-component forces applied to said body, by a surface of the wall of a structure bore, upon said stabilizer being inserted into such bore. .Iaddend. .Iadd.15. A friction stabilizer, according to claim 13, wherein said material comprises means which, responsive to an axial translation of said stabilizer, due to strata separation, or the like, of a bored structure in which said stabilizer shall have been inserted, causes said body to retain such frictional engagement thereof with the wall of a bore in such structure as to maintain substantially all said given anchoring force. .Iaddend.