CAJ | 학술논문

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.
지하암체중,천연지존재유허다미관렬문여절리.재충격회전적연합작용하,충격사근찬두적암석발생렬문단렬、파쇄,형성파쇄소갱;사원리찬두적암석중적미관렬문확전、련통、심지단렬.재리찬두경원구역,사암석산생신적미관렬문.회전사충격산생적파쇄소갱연원주방향확대,병사찬두상적금강석과립환위.재회전충격적연합작용하,암석중적렬문불단산생、확전、단렬,종이체도고속쇄암적목적.
The rock broken mechanism of percussive-rotary drilling was discussed preliminarily by fracture mechanics meth-od.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 direc-tion, and changes the positions of diamond particles on bit.