激光辅助破岩可钻性评价

Rock Drillability Evaluation of Laser Assisted Rock Breaking

激光辅助破岩是一种新的破岩方法。采用高能量激光束照射岩石表面,研究岩石对激光束的敏感性,并对激光辅助破岩的可钻性进行评价。结果表明,给定工艺参数下,砂岩激光钻孔处理后表面分为灰色瓷釉层、白色热影响区和褐色热影响区三个区域。与砂岩相比,花岗岩经激光照射后表面生成具有一定尺寸的透明玻璃泡,玻璃泡周围形成大面积起裂区,且相同工艺参数下钻孔深度明显降低。激光照射花岗岩后可钻性级数较未处理岩石明显降低,表面具有明显的磨损和滑擦痕迹,孔周围有裂纹及破碎现象,原始玻璃釉层出现明显的碎裂。激光照射砂岩后可钻性级数变化不大,表面出现磨损和滑擦痕迹,孔周围未见塑性变形。

Laser assisted rock breaking was a new rock breaking method.The rock surfaces were irradiated by the high energy laser beam and sensitivity of the rock to the laser beam was studied and drillability of laser assisted rock breaking was evaluated.The results show that under the given process parameters,sandstone treated surface is divided into grey enamel layer,white heat affected zone and brown heat affected zone on the locations of laser drilling.Compared with the sandstone,the transparent glass bubble with a certain size is generated on the surface of granite irradiated by laser beam,a widespread crack initiation region is formed around the glass bubble,and the drilling depth decreases obviously under the same process parameters.Drillability grade of the granite irradiated by laser beam is reduced obviously compared with the untreated rocks,and significant wear and scuff marks are appeared on the surface,cracks and fragmentation are formed around the drilling holes,and obvious fragmentation is appeared on the original glass enamel layer.Drillability grade of sandstone irradiated by laser beam is less changed,wear and scuff marks are appeared on the surface,and no plastic deformation is generated around the drilling hole.