Patent ID: 8021083

Claim:
A grout pack assembly, comprising: (a) an inflatable grout bag adapted to contain settable cementitious grout pumped into the bag during installation thereof and which, when expanded and set, forms a generally right cylindrical support column capable of bearing a load along an axial length thereof; (b) at least one restraining ring that extends about the grout bag to provide support against circumferential expansion of the grout bag, the at least one restraining ring being formed by an elongate element, the at least one restraining ring having at least one expansion zone adapted to permit a diameter of the ring to be increased from a first diameter to a second diameter in response to expansion of the grout bag without material deformation of the at least one elongate element; and (c) at least one connector connecting a first section of the elongate element to a second section of the elongate element in an overlapping configuration to form the at least one expansion zone, wherein the connector imparts a pre-determined compressive force on the second section that permits the first section and the second section to move relative to one another and creates a frictional resistance to movement of the second section relative to the first section, thereby allowing the ring to increase in diameter from the first diameter to the second diameter, and providing a progressive yield characteristic to the grout pack assembly.