激光辅助破岩实验研究

EXPERIMENTAL STUDY ON ROCK FRAGMENT ASSISTED BY LASER TECHNOLOGY

采用高能激光束照射岩石表面,研究花岗岩和砂岩对激光热作用的敏感性规律,并对两种岩石的激光破岩效果进行表征。结果表明,激光照射花岗岩时,表面发生热应力破碎,生成透明玻璃泡,且有不同程度起裂。当激光功率(P=700 W)和作用时间一定时,随离焦量增大,玻璃泡直径先减小后增大。砂岩表面激光钻孔后,由黑色瓷釉层和褐色热影响区组成。当激光功率和作用时间一定时,随离焦量增大,砂岩钻孔直径、白色区直径和褐色热影响区直径均呈先增大后减小的趋势,且在离焦量L=103 mm时达到最大值。随激光入射角度的增大,砂岩孔型由圆形向椭圆形转变,且钻孔的黑色瓷釉层、红色和褐色热影响区基本呈现逐渐增大的趋势,钻孔直径变化不大,而孔深相应降低。

The sensibility rules of granite and sandstone on the laser heat were studied and the effects of rock fragment were characterized by using laser beam with high energy irradiated on the surface of rocks. The results showed that heat stress breakage occurred on the surface of granite irradiated by laser beam,and transparent glass bulbs and cracks were also generated.When the laser power and interaction time were constant,the diameter of glass bubble decreased first and then increased along with the increase of the defocusing distance. The sandstone irradiated by laser beam was composed of black ceramic glaze layer and brown heat affected zone. When the laser power and interaction time were constant,the diameters of the hole and the brown heat affected zone increased first and then decrease along with the increase of the defocusing distance. The maximum value was reached when the defocusing distance was 103 mm. Along with the increase of injection angle,the shape of the hole transformed from circular to ellipse,and the black ceramic glaze layer and brown heat affected zone all increased. The diameter of drilling hole changed little while the depth of the drilling hole decreased.