冲击回转碎岩机理探讨

Discussion on Rock Broken Mechanism of Percussive-Rotary Drilling

摘要:

地下岩体中，天然地存在有许多微观裂纹与节理。在冲击回转的联合作用下，冲击使近钻头的岩石发生裂纹断裂、破碎，形成破碎小坑；使远离钻头的岩石中的微观裂纹扩展、连通、甚至断裂。在离钻头更远区域，使岩石产生新的微观裂纹。回转使冲击产生的破碎小坑沿圆周方向扩大，并使钻头上的金刚石颗粒换位。在回转冲击的联合作用下，岩石中的裂纹不断产生、扩展、断裂，从而达到高速碎岩的目的。

Abstract:

The rock broken mechanism of percussive-rotary drilling was discussed preliminarily by fracture mechanics method. There are a lot of joints and micro-fissures in rock matrix. Shock forces make fissures in rocks nearby bit fracture, break and form crater let, make micro-fissures in rocks a little far from bit expand, joint and even break, and make rocks farther from bit generate new micro-fissures. Rotation enlarges the crater lets formed by shock along circumferential direction, and changes the positions of diamond particles on bit.