Tunneling for underground power and pipelines

1. A tunnel boring machine, comprising:

a propulsion system;

a torch support structure carried by the propulsion system; and

a set of plasma torches:

carried by the torch support structure;

configured to gasify a first portion of subterranean material from a face of a tunnel; and

configured to melt a second portion of subterranean material from the face of the tunnel to form a vitrified-rock wall lining the tunnel;

wherein the set of plasma torches melts the second portion of subterranean material comprising up to 60% of subterranean material encountered in the tunnel by the set of plasma torches.

2. The tunnel boring machine of claim 1 , wherein the set of plasma torches are arranged on the torch support structure in a spiral pattern.

3. The tunnel boring machine of claim 1 , wherein each plasma torch in the set of plasma torches comprises a non-transferred arc plasma torch.

4. The tunnel boring machine of claim 1 , wherein each plasma torch in the set of plasma torches comprises a transferred arc plasma torch.

5. The tunnel boring machine of claim 1 :

wherein the torch support structure comprises:

a first disc mounted on a rotatable shaft carried by the propulsion system; and

a second disc offset from the first disc and mounted on the rotatable shaft;

wherein the set of plasma torches comprises:

a first subset of plasma torches arranged in a first spiral pattern on the first disc; and

a second subset of plasma torches arranged in a second spiral pattern on the second disc; and

wherein the propulsion system rotates the rotatable shaft at a speed based on power output of the set of plasma torches and density of material at the face of the tunnel.

6. The tunnel boring machine of claim 5 :

further comprising a laser arranged proximal a center of the torch support structure and configured to create an initial guidance bore at the face of the tunnel; and

wherein the set of plasma torches are configured to gasify the first portion of subterranean material from the face of the tunnel around the initial guidance bore.

7. The tunnel boring machine of claim 1 , further comprising a vacuum system configured to create a vacuum in the tunnel to remove the first portion of subterranean material gasified by the set of plasma torches.

8. The tunnel boring machine of claim 1 , wherein the set of plasma torches is configured to melt the second portion of subterranean material from the face of the tunnel to form the vitrified-rock wall sealed along the tunnel to prevent liquids from entering the tunnel.

9. The tunnel boring machine of claim 1 , wherein the set of plasma torches is configured to melt the second portion of subterranean material from the face of the tunnel to form the vitrified-rock wall sealed along the tunnel to increase structural integrity of the tunnel.

10. The tunnel boring machine of claim 1 , further comprising:

a set of power, supply, and communications cables extending to a base station outside the tunnel;

a protective tube:

housing the set of power, supply, and communications cables; and

lined with a set of wheels configured to run within the tunnel behind the propulsion system; and

a pull cart arranged in the tunnel, offset behind the propulsion system, coupled to the protective tube, and configured the assist the propulsion system in pulling the protective tube through the tunnel.

11. The tunnel boring machine of claim 1 :

wherein the torch support structure comprises a first disc of a first diameter;

wherein the set of plasma torches are arranged in a first spiral pattern on the first disc; and

further comprising a second rig:

coupled to and offset behind the propulsion system;

comprising a second disc of a second diameter greater than the first diameter; and

comprising a second set of plasma torches arranged in a second spiral pattern on the second disc.

12. The tunnel boring machine of claim 11 , further comprising a third rig:

arranged behind the second rig;

comprising a third disc of a third diameter greater than the second diameter; and

comprising a third set of plasma torches arranged in a third spiral pattern on the third disc.

13. The tunnel boring machine of claim 1 , further comprising a second rig:

coupled to and offset behind the propulsion system;

comprising a second torch support structure;

comprising a second set of plasma torches arranged on the second torch support structure; and

cooperating with the set of plasma torches to melt subterranean material from the tunnel to form the vitrified-rock wall lining the tunnel.

14. The tunnel boring machine of claim 1 , further comprising a controller configured to:

actuate the propulsion system to advance the set of plasma torches toward the face of the tunnel;

actuate the set of plasma torches to melt the second portion of subterranean material from the face of the tunnel; and

pause actuation of the set of plasma torches to allow a temperature of the face of the tunnel to decrease before further advancing the set of plasma torches toward the face of the tunnel.

15. A tunnel boring machine, comprising:

a propulsion system;

a torch support structure carried by the propulsion system;

a set of plasma torches:

carried by the torch support structure;

configured to gasify a first portion of subterranean material from a face of a tunnel; and

configured to melt a second portion of subterranean material from the face of the tunnel to form a vitrified-rock wall lining the tunnel;

a set of power, supply, and communications cables extending to a base station outside the tunnel; and

a protective tube:

housing the set of power, supply, and communications cables; and

comprising a refractive protection over a first length trailing the propulsion system.

16. The tunnel boring machine of claim 15 , wherein each plasma torch in the set of plasma torches comprises a non-transferred arc plasma torch.

17. The tunnel boring machine of claim 15 , wherein each plasma torch in the set of plasma torches comprises a transferred arc plasma torch.

18. A tunnel boring machine, comprising:

a propulsion system;

a torch support structure carried by the propulsion system;

a set of plasma torches:

carried by the torch support structure;

configured to gasify a first portion of subterranean material from a face of a tunnel; and

configured to melt a second portion of subterranean material from the face of the tunnel to form a vitrified-rock wall lining the tunnel;

a sensor; and

a controller configured to:

detect a mineral content of the first portion of subterranean material, gasified by the set of plasma torches, based on an output of the sensor; and

indicate need for a secondary liner in the tunnel, in addition to the vitrified-rock wall, based on the mineral content.

19. The tunnel boring machine of claim 18 , wherein each plasma torch in the set of plasma torches comprises a non-transferred arc plasma torch.

20. The tunnel boring machine of claim 18 , wherein each plasma torch in the set of plasma torches comprises a transferred arc plasma torch.