Adjustable cap for column foundation

Abstract

A cap 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 cap 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 cap having a top structure-engaging surface;   supporting said cap while adjusting a position of said cap with respect to said foundation column with at least two degrees of freedom;   providing a second settable material between said foundation column and said cap while maintaining said position;   hardening said second settable material to make said cap structurally integral with said foundation column with said cap 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 cap. 
     
     
         4 . The method as defined in  claim 3 , wherein said supporting said cap comprises fastening said cap to 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 cap 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 a cylindrical member. 
     
     
         7 . The method as defined in  claim 6 , wherein said column structure is a cylindrical tube and filled with said first settable material. 
     
     
         8 . The method as defined in  claim 1 , wherein said first settable material and said second settable material are cement. 
     
     
         9 . The method as defined in  claim 1 , wherein said supporting said cap while adjusting a position of said cap with respect to said foundation column with at least two degrees of freedom comprises using adjustment screws extending from said cap to said foundation column. 
     
     
         10 . The method as defined in  claim 9 , wherein said adjustment screws include vertical adjustment screws extending between a horizontal member of said cap and a horizontal member of said foundation column. 
     
     
         11 . 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 in accordance with  claim 1 , wherein said position of said cap corresponds to said position and orientation for said at least one leg;   securing said at least one leg to said cap.   
     
     
         12 . The method as defined in  claim 11 , wherein said tower comprises four legs, said installing comprising installing four said foundations. 
     
     
         13 . The method of  claim 11 , further comprising connecting three tension members to each foundation and applying tension to the foundation via the tension members. 
     
     
         14 . The method of  claim 12 , further comprising connecting at least one tension member between two foundations. 
     
     
         15 . The method of  claim 12 , 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. 
     
     
         17 . The method of  claim 16 , wherein the substrate comprises a bedrock. 
     
     
         18 . A cap 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;   a sidewall casing extending downwardly from said top member;   at least three positioning members for engaging said column-type foundation;   a seal located on an inside of the sidewall casing near a bottom of the sidewall casing; and   aperture for filling the cap with a settable material when connected to a column-type foundation.   
     
     
         19 . The cap as defined in  claim 18 , wherein said position members include positioning members mounted in the sidewall casing to be adjustable in position extending into the sidewall casing. 
     
     
         20 . The cap as defined in  claim 18 , wherein said position members include positioning members mounted in said top member for engaging a top member of said column-type foundation to provide for vertical adjustment and leveling. 
     
     
         21 . The cap as defined in  claim 20 , wherein said top member comprises a cover plate connected to said sidewall casing and a base member fastenable to said cover plate. 
     
     
         22 . A cap 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.