Patent ID: 7651302

Claim:
A method for increasing stiffness of bearing strata formed of soil, rock or other geomaterial, comprising the steps of: forming a shaft in said soil, rock, or other geomaterial with a drill bit, said shaft having a foundation tip; compressing soil, rock, or other geomaterial beneath the foundation tip of the shaft; compressing said soil, rock, or other geomaterial by forming a void in said soil, rock, or other geomaterial beneath said foundation tip of said shaft by injecting non-hardening pre-compression fluids into said bearing strata formed of said soil, rock, or other goematerial to cause pre-compression of said soil, rock, or other geomaterial beneath said foundation tip of said shaft; said non-hardening pre-compression fluids creating said void beneath said foundation tip of said shaft by squeezing water from voids in said soil, rock, or other geomaterial; filling said void with said non-hardening pre-compression fluids and maintaining said non-hardening pre-compression fluids in said void for a length of time sufficient to allow water to be squeezed from said soil, rock, or other geomaterial beneath said foundation tip of said shaft; removing said non-hardening pre-compression fluids from said void; filling said void with cement grout; and curing said cement grout in the substantial absence of additional pressure; whereby end bearing capacity is improved at least ten times greater than the bearing capacity of an unimproved foundation.