Shigen-to-sozai, Vol.116, No.12, pp.988-993.
Numerical Simulation of Drilling with Button
Bit
Seisuke OKUBO1 and Katsunori FUKUI1
| 1. Department of Geosystem Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 |
| Development of a powerful hydraulic rotary
/ percussive drill motivates improvement
of drill rods and bits. Recently a button
bit is preferably used for its durability
and high maximum drilling rate. However,
its penetration /rock-breaking mechanism
is so complicated and many parameters are
involved, then very few fundamental studies
have been published up to now. Very recently, authors had been carried out a series of button-chip penetration tests changing applied load, spacing and diameter of a button chip. In the first part of this paper, a computer program to simulate the static penetration test is stated. In case of Inada granite, it was found that the depth of groove produced by a series of static penetrations can be calculated by adding each depth / damage of a single penetration and making slight correction against the effect of unevenness of rock surface. Finally, the simulation program was modified and computer simulation was carried out to estimate drilling rate by a button bit with six button chips. Simulation results were compared with results of drilling tests performed at various index angles. |
| KEY WORDS: Drilling, Rock Drill, Burton Bit, Button Chip, Numerical Simulation |