Document Type : Original Research Paper

Authors

1 Faculty of Mining Engineering & Geophysics, Shahrood University of Technology, Shahrood, Iran

2 Faculty of Mining Engineering, Sahand University of Technology, Tabriz, Iran

Abstract

     Drilling is one of the most expensive stages of open pit mining and has more complexity. In drilling process many parameters influence simultaneously, where studying each parameter requires recognition of the effects of the characteristics of the rock mass and its material.
In this paper, the main aim was directed to investigate the joints dipping among the structural parameters of the rock mass. In the course of study, geometrical condition of penetration and transition of drill bit from joint surface were analyzed and different conditions of dips considered mathematically. This was followed by physical modeling of each of the geometrical conditions and penetration rate of cross bit measured by using rotary drilling system. Based on the numerical results obtained from experiments, mathematical equation between angles of joint dip with respect to drilling prolongation and penetration rates was presented. Furthermore, in conformity with the presented equation, by decreasing relative angle of joints dip, penetration rate of drill bit in jointed rock masses decreases linearly.

Keywords

Refrences
Ersoy, A. &  Waller., M.D., 1995 - Textural characterization of rocks.  Engineering Geology, Volume 39, Issues 3-4, June,                               Pages123-136
Jimeno, C. L., Jimeno, E.L. & Carcedo, F.J.A., 1995- Drilling and blasting of rocks,Balkema. Pages 1-14
Kaiser, P.K. & McCreath, D.R., 1994- Rock mechanics considerations for drilled or bored excavations in hard rock. Tunneling and Underground Space Technology,Volume 9, Issue 4, October, Pages 425-437
Singh, S.P., 1990- Rock drillability comparison by different methods, Proc 2nd   International Symposium on Mine Planning and Equipment Selection, Calgary, 7–9 November, A.A Balkema, Publ Rotterdam, Pages 489–494
 Singh, S.P., Ladouceur, M. & Rouhi, F., 1998- Sources, implication and control of  blasthole deviation, International Symposium on Mine Planning and Equipment  Selection, A.A Balkema, Publ Rotterdam, Pages 391-397  
Jung, S.J., Prisbrey, K. & Wu, G., 1994- Prediction of rock hardness and drillability  using acoustic emission signatures during indentation. International Journal of Rock  Mechanics and Mining Science, Volume 31, Issue 5, October, Pages 561-567
Kahraman, S., Balci, C., Yazici, S. & Bilgin, N., 2000- Prediction of the penetration rate of  rotary blasthole drilling using a new drillability index, International Journal of Rock  Mechanics and Mining Science, 37, Pages 729-743
Kahraman, S., 1999- Rotary and percussive drilling prediction using regression analysis, International Journal of Rock Mechanics and Mining Sciences, 36, Pages 981-989.   
Drake, R., 2004- Bench drilling techniques and equipment selection manual, Pages 1-40.         
Wijk, G., 1991- Rotary drilling prediction, International Journal of Rock Mechanics and Mining Science, Volume 28, Issue 1, January, Pages 35-42
Wilbur, Lyman, D., 1982- Rock Tunnel Engineering Handbook, Edited by BickeL and Kuesel, A publication of van Norstrand Reinhold company , Pages 123-207
Zhu, S.T., 1988- Experimental study of drillability for rotary rock bits , Proc International  Symposium on Mine Planning and Equipment Selection, calgary, 3–4 November 1988, A A Balkema, Publ Rotterdam, Pages 375–381.