Sliding concave foundation system

Abstract

A foundation system for a building or other load includes a lower part and an upper sliding raft. The lower part has a generally concave surface at the top thereof. The upper sliding raft has a convex surface at the bottom thereof adapted to rest on the concave surface of the lower part and allow for sliding rotational movement therebetween. The building or other load is attached to the upper sliding raft.

What is claimed as the invention is:  
     
         1 . A foundation system for a building or other load comprising; 
 a lower part having a generally concave surface at the top thereof;    an upper sliding raft having a convex surface at the bottom thereof adapted to rest on the concave surface of the lower part and allow for sliding rotational movement therebetween and wherein the building is attached to the upper sliding raft.    
     
     
         2 . The foundation system as claimed in  claim 1  wherein the concave surface of the lower part is generally cylindrical.  
     
     
         3 . The foundation system as claimed in  claim 2  wherein the lower part and the upper sliding raft each has an interface made of very low friction material.  
     
     
         4 . The foundation system as claimed in  claim 3  wherein the very low friction material interfaces has constant static and dynamic characteristics.  
     
     
         5 . The foundation system as claimed in  claim 3  wherein the very low friction material interfaces is one of steel-Teflon and Teflon-Teflon.  
     
     
         6 . The foundation system as claimed in  claim 3  wherein the upper sliding raft includes a concrete platform resting on a plurality of short and rigid stands, the stands collectively having the convexity corresponding to the concave surface of the lower part.  
     
     
         7 . The foundation system as claimed in  claim 3  wherein the upper sliding raft includes a solid sector of a cylinder that matches the concave surface of the lower fixed foundation.  
     
     
         8 . The foundation system as claimed in  claim 3  wherein the upper sliding raft includes a combination of a concrete platform resting on a plurality of short and rigid stands, the stands collectively having the convexity corresponding to the concave surface of the lower part and a solid sector of a cylinder that matches the concave surface of the lower fixed foundation.  
     
     
         9 . The foundation system as claimed in  claim 3  wherein the concave surface has a center of curvature and the building has a center of gravity and the center of curvature of the concave surface is above the center of gravity of the building.  
     
     
         10 . The foundation system as claimed in  claim 3  wherein the concave surface has a radius of curvature and the building has a height and the radius of curvature of the concave surface is at least half the height of the building.