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Systems and methods for filling submerged voids with a foam-fluidized fill material in an efficient and economical manner are disclosed herein. The foam fluidized fill material is a granular solid material fluidized with a foam. The foam-fluidized fill material is pumped or gravity-fed through an in

Systems and methods for filling submerged voids with a foam-fluidized fill material in an efficient and economical manner are disclosed herein. The foam fluidized fill material is a granular solid material fluidized with a foam. The foam-fluidized fill material is pumped or gravity-fed through an insertion tube into the submerged void. The insertion tube terminates at a point lying below a surface of the liquid within the void. Since the foam-fluidized fill material is heavier than the liquid, the foam-fluidized fill material exiting the insertion tube sinks to the bottom of the void and expands laterally at the bottom of the void displacing the liquid. The liquid is forced upward and out of the void where it may be collected. Further, as the fill material fills the void, the foam dissipates and the fill material self compacts, making the filled void sufficiently load bearing.

대표청구항 ▼

1. A method for filling a subterranean void, the method comprising: injecting a foam-fluidized granular fill material into the void and leaving the granular material in the void, the injecting being at an injection point beneath a surface of water within the void, wherein the foam-fluidized granular

1. A method for filling a subterranean void, the method comprising: injecting a foam-fluidized granular fill material into the void and leaving the granular material in the void, the injecting being at an injection point beneath a surface of water within the void, wherein the foam-fluidized granular fill material is injected at a velocity sufficient for the foam-fluidized granular fill material to expand laterally within the void at least two times more than if the granular fill material was not foam-fluidized and to displace the water, and wherein foam within the foam-fluidized granular fill material dissipates, rather than being removed from the void, as the foam-fluidized granular fill material expands laterally within the void, thus self-compacting the granular fill material. 2. The method of claim 1, wherein the density of the foam-fluidized granular fill material is greater than the density of the water. 3. The method of claim 1, further comprising: drilling a hole from a surface to access the void. 4. The method of claim 3, further comprising: inserting an injection tube through the hole in the void, wherein a distal end of the injection tube extends beneath the surface of the water, and wherein the injection operation is performed using the injection tube. 5. The method of claim 4, further comprising: monitoring pressure of the foam-fluidized granular fill material within the injection tube; andwithdrawing the injection tube an incremental distance if the pressure rises above a predetermined maximum. 6. The method of claim 4, further comprising: monitoring flow rate of the foam-fluidized granular fill material within the injection tube; andwithdrawing the injection tube an incremental distance if the flow rate drops below a minimum flow rate. 7. The method of claim 1, further comprising: collecting the water displaced by the injected foam-fluidized granular fill material. 8. The method of claim 1, wherein the foam-fluidized granular fill material is a homogeneous mixture of at least granular solid fill material, a surfactant, and air. 9. The method of claim 8, wherein the granular solid fill material is sand. 10. The method of claim 1, wherein the void contains a second liquid below the water, wherein the second liquid has a density greater than the water, and wherein the foam-fluidized granular fill material expands laterally between the water and the second liquid and displaces the water. 11. The method of claim 10, wherein the density of the foam-fluidized granular fill material is greater than the density of the water and less than the density of the second liquid. 12. The method of claim 1, wherein the foam-fluidized granular fill material becomes less fluid and more compacted as it expands laterally within the void. 13. The method of claim 1, wherein the injection operation is gravity-driven or pressure-driven. 14. The method of claim 1, wherein the foam-fluidized granular fill material expands laterally at least 2.5 times more than if the granular fill material was not foam-fluidized. 15. A method of filling a submerged void comprising: drilling a hole from a surface to access the submerged void;inserting an injection tube from the surface and through the hole, wherein a distal end of the injection tube extends beneath a surface of a liquid within the submerged void;injecting a foam-fluidized granular fill material with a density greater than that of the liquid into the submerged void through the injection tube at a velocity sufficient for the foam-fluidized granular fill material to expand laterally at least two times more than if the granular fill material was not foam-fluidized and to displace the liquid, with the foam within the foam-fluidized granular fill material dissipating, rather than being removed from the void, as the foam-fluidized granular fill material expands laterally within the void, thus self-compacting the granular fill material; andleaving the self-compacted granular material in the void. 16. The method of claim 15, further comprising: collecting the liquid displaced by the injected foam-fluidized granular fill material. 17. The method of claim 15, wherein the liquid is discharged from the void via the drilled hole. 18. A method comprising: calculating a maximum hole spacing for filling a submerged void;drilling two or more holes from a surface to access the submerged void, wherein the holes are spaced no further apart than the calculated maximum hole spacing;inserting an injection tube from the surface and through each of the holes, wherein a distal end of each of the injection tubes extends beneath a surface of a liquid within the submerged void; andinjecting a foam-fluidized granular fill material with a density greater than that of the liquid into the submerged void through the injection tubes at a velocity sufficient for the foam-fluidized granular fill material to expand laterally at least two times more than if the granular fill material was not foam-fluidized and to displace the liquid, with the foam within the foam-fluidized granular fill material dissipating, rather than being removed from the void, as the foam-fluidized granular fill material expands laterally within the void, thus self-compacting the granular fill material; andleaving the self-compacted granular material in the void. 19. The method of claim 18, further comprising: collecting the liquid displaced by the injected foam-fluidized granular fill material. 20. The method of claim 18, wherein the liquid is discharged from the void via one or more of the drilled holes.