采用激光辅助机械破岩,激光束照射砂岩后再进行机械破岩,研究砂岩对激光热作用的敏感性规律并对其力学性能和可钻性进行研究.结果表明,激光照射砂岩表面时,离焦量和作用时间是影响钻孔直径和深度的重要参数,而激光功率主要影响钻孔深度.激光照射在砂岩表面形成具有一定直径、深度的破碎坑,由灰色瓷釉层和褐色热影响区组成.原始砂岩由石英、高岭石和伊利石组成,抗压强度为36.4MPa,属于低强度岩石.激光照射后灰色瓷釉层和褐色热影响区主要含石英和高岭石,且石英含量增加,随激光钻孔密度的增大,砂岩抗压强度和可钻性级数均降低.

Laser assisted mechanical processing was applied to break sandstone and the sensitivity rule of sandstone to laser thermal effect,its mechanical properties and drill ability were studied. The results show that the defocus distance and interaction time are the important parameters for the diameter and depth of laser perforation and the laser power mainly affects the depth. Laser irradiation induces the formation of pit,which consists of grey glaze layer and brown HAZ. The sandstone is composed of SiO2,Al2Si2O5(OH)4 and Al2Si3AlO10(OH)2 and the compressive strength is 36.4MPa,belonging to low strength rock. After laser irradiation,the grey glaze layer and brown HAZ mainly consists of SiO2 and Al2Si2O5(OH)4,and the content of SiO2 increases. Moreover,with the increment of density of laser perforation,the compressive strength and drill ability index decrease.