Numerical study of effects of borehole pressure on bit-teeth induced rock fragmentation

作者：Shi Xiangchao^*; Cai Wuqiang; Meng Yingfeng; Jin Wencheng; Li Gao; Tao Zuwen

来源：Electronic Journal of Geotechnical Engineering, 2014, 19 T: 4743-4752.

• Basic mechanism
• Bit-tooth
• Borehole pressure
• Main mode
• Optimal space
• Rock failures
• Rock fragmentation
• Side-crack

The effect of the borehole pressure on the rock fragmentation of a bit has been studied extensively. However, its basic mechanism remains controversial. In the study a discrete element method is used to study the rock fragmentation process of single, double bit-teeth indentation under different borehole pressures. The results show that the borehole pressure impedes the propagation and initiation of cracks. With an increase in borehole pressure, the side crack length decrease significantly; furthermore, the main mode of rock failure shifts from tension to shear. Based on these results, an analytical relationship between the borehole pressure and the optimal space between bit-teeth is established. Engineer can use the same as a reference when designing and choosing bits.

• 出版日期2014
• 单位四川大学