Experimental study on tensile strength and pore distribution of granite by laser irradiation
WU Bo
LIU Lin
YU Dongxu
WANG Jianzhou
WANG Yijiang
Abstract：Laser-assisted rock-breaking technology contributes to enhance the mining efficiency of re-sources in ultra-hard and ultra-deep formations.A laser thermal cracking test on granite is carried out using the controlled variable method,and the changing rules of radial temperature,borehole parame-ters,specific energy,thermal-cracking energy,tensile strength and pore distribution were researched.The results reveal that the temperature of granite surface under laser action is more than 1 000 ℃,and the diameter,depth and rate of granite perforation vary nonlinearly with the irradiation parameters,and the maximum diameter,depth and rate of perforation are 10.0 mm,12.0 mm and 2.70 mm/s.The maximum specific energy and thermal-cracking energy of granite are 87.8 kJ/cm3 and 39.5 kJ/cm3,re-spectively.The damage pattern of granite is brittle fracture after laser irradiation,and the maximum decrease of tensile strength is 74.11％.The large pores generate under laser action by connecting of small and medium-sized pores in the rock,which ultimately results in the fracture of the rock.
Keywords：laser-assisted rock-fracturingtemperature distributionthermal-cracking energytensile str-engthnuclear magnetic resonance
Publication Date：2024-08-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 88-94,74 )