Adjustable cap for column foundation

Abstract

A head for a column-type foundation is adjustable with respect to its foundation. A top member has a support member for mating with and securing a leg of a structure and a central aperture for receiving an anchor rod of the column-type foundation. A sidewall casing extends downwardly from the top member and at least three positioning members engage the foundation. A seal is located on an inside of the sidewall casing near a bottom of the sidewall casing. The head is filled with a settable material when connected to the foundation.

What is claimed is: 
     
         1 . A method of installing a foundation comprising:
 drilling a borehole;   providing a column structure in said borehole;   filling at least a space between said borehole and said column structure with a first settable material;   hardening said first settable material wherein said column structure combined with said first settable material forms a foundation column;   providing a head having a top structure-engaging surface;   supporting said head while adjusting a position of said head with respect to said foundation column with at least two degrees of freedom, and adjusting an angular position of a planar surface of said head;   providing a second settable material between said foundation column and said head while maintaining said position; and   hardening said second settable material to make said head structurally integral with said foundation column with said head secured in said position.   
     
     
         2 . The method as defined in  claim 1 , wherein said drilling said borehole comprises drilling through an overburden layer into a bedrock layer, said foundation column deriving lateral stability from said bedrock layer. 
     
     
         3 . The method as defined in  claim 1 , wherein said foundation column comprises a bar extending upwardly for attaching said head. 
     
     
         4 . The method as defined in  claim 3 , wherein said supporting said head comprises fastening said head to said bar at a desired height. 
     
     
         5 . The method as defined in  claim 3 , wherein said providing said second settable material between said foundation column and said head comprise providing a container between said foundation column and a bottom of said top structure engaging surface for containing said second settable material. 
     
     
         6 . The method as defined in  claim 1 , wherein said column structure is one of a cylindrical member and a cylindrical tube and is filled with a settable material. 
     
     
         7 . The method as defined in  claim 1 , further comprising partially filling said column structure with a settable material, up to a height allowing insertion of said head inside said column structure, hardening said settable material partially filling said column structure and inserting said head inside said column structure before said supporting and said adjusting of said head. 
     
     
         8 . The method as defined in  claim 1 , wherein said supporting said head while adjusting a position of said head with respect to said foundation column with at least two degrees of freedom comprises using adjustment screws extending from said head to said foundation column. 
     
     
         9 . The method as defined in  claim 8 , wherein said adjustment screws include vertical adjustment screws extending between a horizontal member of said head and a horizontal member of said foundation column. 
     
     
         10 . The method as defined in  claim 1 , wherein said head comprises a sidewall casing extending downwardly from said top structure-engaging surface to surround said column structure, further comprising a seal located on an inside of said sidewall casing near a bottom of said sidewall casing to prevent leakage of said second settable material. 
     
     
         11 . The method as defined in  claim 1 , wherein said head comprises a sidewall casing extending downwardly from said top structure-engaging surface located inside said column structure. 
     
     
         12 . A method of installing a tower comprising:
 providing the tower having at least one leg;   defining a position and orientation for said at least one leg;   installing at least one foundation, said installing comprising:
 drilling a borehole; 
 providing a column structure in said borehole; 
 filling at least a space between said borehole and said column structure with a first settable material; 
 hardening said first settable material wherein said column structure combined with said first settable material forms a foundation column; 
 providing a head having a top structure-engaging surface; 
 supporting said head while adjusting a position of said head with respect to said foundation column with at least two degrees of freedom; 
 providing a second settable material between said foundation column and said head while maintaining said position; and 
 hardening said second settable material to make said head structurally integral with said foundation column with said head secured in said position, wherein said position of said head corresponds to said position and orientation for said at least one leg; and 
   securing said at least one leg to said head.   
     
     
         13 . The method as defined in  claim 12 , wherein said tower comprises four legs, said installing comprising installing four said foundations. 
     
     
         14 . The method of  claim 12 , further comprising connecting three tension members to each foundation and applying tension to the foundation via the tension members, wherein at least one tension member connects two foundations. 
     
     
         15 . The method of  claim 13 , further comprising connecting four tension members between the four foundations, such that two of the four tension members are connected to each of the four foundations. 
     
     
         16 . The method of  claim 15 , further comprising connecting a tension member from a foundation to a substrate proximate the foundation, wherein said substrate comprises at least one of a bedrock and an overburden layer. 
     
     
         17 . A head for a column-type foundation comprising:
 a top member having a support member for mating with and securing a leg of a structure;   a central aperture for receiving an anchor rod of said column-type foundation; and   a sidewall casing extending downwardly from said top member, said sidewall casing being one of:
 surrounding said column-type foundation and further comprising a seal located on an inside of said sidewall casing near a bottom of said sidewall casing; and 
 located inside a casing of said column-type foundation. 
   
     
     
         18 . The head as defined in  claim 17 , further comprising positioning members for engaging said column-type foundation. 
     
     
         19 . The head as defined in  claim 17 , further comprising at least one of an aperture for filling the cap with a settable material when connected to a column-type foundation or an aperture for ventilation. 
     
     
         20 . The head as defined in  claim 18 , wherein said positioning members comprise at least one of a positioning member mounted in the sidewall casing to be adjustable in position extending into the sidewall casing and a positioning member mounted in said top member for engaging a top member of said column-type foundation to provide for vertical adjustment and levelling. 
     
     
         21 . The head as defined in  claim 17 , wherein said top member comprises a cover plate connected to said sidewall casing and a base member fastenable to said cover plate. 
     
     
         22 . A head for a column-type foundation comprising:
 a top member connectable to a top of the column-type foundation; and   at least three pivotable anchor attachments seated in said top member, each pivotable anchor attachment connectable to a tension anchor for securing the head.