Experimental Investigation on Compressive Strength, Ultrasonic Characteristic and Cracks Distribution of Granite Rock Irradiated by a Moving Laser Beam

Efficient fracturing is the key issue for exploitation of geothermal energy in a Hot Dry Rock reservoir. By using laser irradiation cracking method, this study investigates changes uniaxial compressive strength, ultrasonic characteristics and crack distributions granite specimens by applying beam under various conditions, including different powers, diameters moving speeds beam. The results indicate that strength considerably dependent on power, diameter speed ultrasonic-wave velocity amplitude first wave both increase with decreased increased or form irradiated graphite flattened comparing original specimen without irradiation. angle ratio cracked area at ends are also related to parameters. interior cracks observed be well-developed around bottom grooving kerf generated new economical practical method can efficiently fracture graphite.