Brace assembly for truss legs of offshore structures

Abstract

A brace assembly for truss legs of offshore structures is provided with a reinforcing sleeve mounted on the brace member in the portion of the brace member most prone to buckling under the force of horizontal moment acting on the brace member. The reinforcing sleeve surrounds the critical area of the brace member and provides additional load bearing capacity to the brace member. The reinforcing sleeve is made from a non-corrosive material having physical characteristics suitable to withstand the environmental forces in the location. The reinforcing sleeve may be installed at the shipyard when the offshore structure is manufactured or mounted on the existing rig by an easy retrofit not requiring towing of the offshore structure to the shipyard.

1 . A brace assembly for a truss leg, comprising: 
 an elongated tubular member; and    a reinforcing sleeve positioned about exterior of a pre-determined portion of the tubular member, said sleeve substantially conforming to the exterior configuration of the tubular member.    
   
   
       2 . The apparatus of  claim 1 , wherein said sleeve is formed from a non-corrosive material.  
   
   
       3 . The apparatus of  claim 2;  wherein said non-corrosive material is steel.  
   
   
       4 . The apparatus of  claim 2 , wherein reinforcing sleeve is welded to the tubular member.  
   
   
       5 . The apparatus of  claim 2 , wherein said non-corrosive material is composite fiber material.  
   
   
       6 . The apparatus of  claim 5 , wherein said reinforcing sleeve is adhesively secured on said tubular member.  
   
   
       7 . The apparatus of  claim 5 , wherein said reinforcing sleeve comprises a plurality of layers of the composite fiber material wrapped around exterior of the predetermined portion of the tubular member.  
   
   
       8 . A brace assembly for a truss leg of an offshore structure having vertically extending leg chords, the brace assembly comprising: 
 a first horizontal member extending in a transverse relationship between a first leg chord and a second parallel leg chord;    a second horizontal member extending in a transverse relationship between the first leg chord and the second parallel leg chord below said first horizontal member;    a plurality of angular brace members extending between the first horizontal brace member and the second horizontal brace member; and    wherein each of said first horizontal brace member, said second horizontal brace member, said plurality of angular brace members is provided with a reinforcing sleeve mounted about exterior surfaces thereof.    
   
   
       9 . The apparatus of  claim 8 , wherein each of said reinforcing sleeves covers at least a portion of an outer periphery of a corresponding brace member.  
   
   
       10 . The apparatus of  claim 8 , wherein each of said reinforcing sleeves is formed from a non-corrosive material.  
   
   
       11 . The apparatus of  claim 10 , wherein said non-corrosive material is steel.  
   
   
       12 . The apparatus of  claim 10 , wherein said non-corrosive material is composite fiber material positioned in a plurality of layers about a predetermined portion of a respective brace member.  
   
   
       13 . The apparatus of  claim 12 , wherein said composite fiber material is adhesively secured to the pre-determined portion of a respective brace member.  
   
   
       14 . A method of reinforcing a brace member of a truss leg, comprising the steps of: 
 providing a reinforcing sleeve means for positioning over a pre-determined portion of the brace member;    positioning said reinforcing sleeve means in a surrounding relationship over the pre-determined portion of the brace member, thereby increasing resistance of the brace member to bending loads.    
   
   
       15 . The method of  claim 14 , wherein said reinforcing sleeve means is formed from a non-corrosive material.  
   
   
       16 . The method of  claim 15 , wherein said non-corrosive material is steel.  
   
   
       17 . The method of  claim 15 , wherein said non-corrosive material is composite fiber material.  
   
   
       18 . The method of  claim 14 , wherein said reinforcing sleeve means comprises a hollow member having an interior diameter slightly greater than an exterior periphery of the pre-determined portion of the brace member.