Casting of piles in situ

Claim 1

A PROCESS FOR CONSTRUCTING PILES CAST IN SITU COMPRISING THE STEPS OF FORMING A HOLE OF A DIAMETER EQUAL TO THE NOMINAL DIAMETER OF THE PILE, POURING LIQUID GROUT INTO SAID HOLE AS ITS FORMATION PROCEEDS, INSERTING AXIALLY INTO SAID HOLE FILLED WITH SAID GROUT TO ITS FULL DEPTH WHEN FORMED A COMPLETELY FLEXIBLE AND RESILIENTLY EXTENSIBLE, RADIALLY EXPANSIBLE ELEMENT AND A PREVIOUS METAL CAGE, SAID ELEMENT HAVING A LENGTH APPROXIMATELY EQUAL TO THE DEPTH OF SAID HOLE, SAID PERVIOUS METAL CAGE SURROUNDING SAID ELEMENT AND HAVING A DIAMETER LESS THAN THAT OF SAID HOLE AND EQUAL TO THE MAXIMUM PERMISSIBLE EXPANDED DIAMETER OF SAID ELEMENT, EXPANDING SAID ELEMENT UNDER RADIAL PRESSURE WHEREBY SAID RADIALLY EXPANSIBLE ELEMENT IS EXPANDED APPROXIMATELY EQUALLY RADIALLY, MAINTAINING SAID PRESSURE UNTIL SAID GROUT SETS TO FORM A LINING FOR SAID HOLE, RELEASING SAID RADIAL PRESSURE TO CAUSE SAID EXPANSIBLE ELEMENT TO PULL AWAY FROM SAID LINING, REMOVING SAID ELEMENT AND FILLING THE CAVITY LEFT THEREBY WITH LOAD-BEARING CONCRETE.