THERE IS A CRITICAL NEED FOR INNOVATIVE CONCEPTS FOR RAPID TUNNELING IN HARD ROCK.

THERE IS A CRITICAL NEED FOR INNOVATIVE CONCEPTS FOR RAPID TUNNELING IN HARD ROCK. RESEARCH SPONSORED PARTLY BY DNA HAS RECENTLY INDICATED THAT IT MAY BE POSSIBLE TO FORM POWERFUL ELECTRICAL ARCS WITHIN HARD ROCK. THIS WOULD BE ACCOMPLISHED BY PLACING TWO ELECTRODES, SPACED UP TO SEVERAL FEET APART, AGAINST THE ROCK SURFACE AND PULSING THEM WITH HIGH VOLTAGE. A HIGH CURRENT ARC DISCHARGE IS EXPECTED TO FORM MANY INCHES BELOW THE SURFCE. THE DEPOSITION OF ARC ENERGY WOULD BE EQUIVALENT TO DETONATING HIGH EXPLOSIVE WITHIN THE ROCK, THEREBY REMOVING THE SURFACE LAYER. BY MOVING THE ELECTRODES FROM PLACE TO PLACE ON THE TUNNEL FACE AND REPETITIVELY PULSING THEM, RAPID MATERIAL REMOVAL RATES SHOUD BE ACHIEVABLE. PRELIMINARY ESTIMATES INDICATE THAT TUNNELING RATES OF 1,000 FEET PER DAY MAY BE POSSIBLE IN 20-FOOT DIAMETER TUNNELS WITH A 2 MEGAWATT SYSTEM COSTING LESS THAN $1 MILLION (EXCLUDING DEBRIS REMOVAL). EXPERIMENTS WILL BE PERFORMED TO DEMONSTRATE THE FEASIBILITY OF THE ARCSHATTERING CONCEPT. THEORETICAL MODELING WILL BE DEVELOPED TO ESTIMATE THE SCALING OF KEY PARAMETERS TO LARGE SYSTEMS, AND THE CONCEPTUAL DESIGN AND COSTING WILL BE SCOPED FOR A FULL SCALE TUNNELING MACHINE.