Experimental Research on Rotation-Percussion Drilling of Diamond Bit Based on Stress Wave

Abstract

Rotary-percussive drilling is a common form of drilling in geotechnical engineering. in order to study the effect of rotational speed and impact speed on rock-breaking efficiency, a drilling simulation platform developed by ourselves and a drill pipe equipped with diamond bit were used to conduct simulated drilling experiments. By monitoring the stress wave during drilling, the strain, stress and energy changes at different rotational speeds and impact velocities can be obtained, and the optimal drilling parameters can be determined. The results show that both speed and impact velocity have direct influence on the drilling process. When the rotational speed is kept constant, the drilling efficiency increases first and then decreases with the increase of the impact velocity. When the impact velocity remains constant, the drilling efficiency decreases with the increase of rotating speed. With the increase of rotational speed, the optimal impact velocity also increases. It is helpful to improve the drilling efficiency by reasonable choice of speed and impact speed.