Engineering Geology

Engineering Geology

Modification of Schimazek Abrasivity Index for Improving its Application in Rock Engineering

Authors
M Ataei
sh. hosseini
S.H Hoseinie
10.18869/acadpub.jeg.11.1.73
Abstract
./files/site1/files/4Extended_Abstract.pdfExtended Abstract

(Paper pages 73-90)

Introduction

Up to now, various indexes and methods have been presented for evaluating the abrasivity of rocks. In total, these methods can be divided to two main groups; the methods based on nature of rocks, methods based on heuristic tools. Schimazek F-abrasivity index is one of the most powerful and applicable indexes for evaluating the rock abrasiveness. This index uses the grain size, Brazilian tensile strength and equivalent quartz content for abrasivity analysis. Since the values of these parameters are equal in Schimazek index, therefore, in some cases this index doesn't have suitable ability to distinguish and classify the rock abrasiveness. This paper tries to modify the Schimazek index considering the weights of its applied parameters.

Material and Methods

In this research, Fuzzy Delphi Analytical Hierarchy Process (FDAHP) has been used to calculate the weight of dominant parameters in rock abrasivity. For this purpose several questioners have been distributed and the expert opinions were collected. The results showed that the quartz content, grain size and tensile strength have the weight of 0.4, 0.31 and 0.29 respectively and new Schimazek F-abrasivity index is as presented in equation (1).



In the next stage, in order to facilitate the application of new index, a new classification system was developed. This classification and related weighing graphs (Figure 1) help to change the discontinuous classification to continuous one.

Results and discussions

In order to verify the application of the new developed index, ten ornamental stones have been studied and the old and modified Schimazek indexes were calculated for all of them. Then, the cutting rate (sawing rate) of each stone was recorded in laboratory and the mathematical relationships between new and old indexes have been achieved. The results show that the new Schimazek abrasivity index has higher ability to predict the cutting rate than old one (Figure 2).





Figure1. Continuous weighting for parameters of Schimazek F-abrasivity index





Figure2. Regression of old and new Schimazek F-abrasivity index with cutting rate of granite ornamental stones

Conclusion

Generally it could be concluded that, the main weakness of Schimazek F-abrasivity index which is the equality of parameters’ importance, has been removed by idea developed and confirmed in this study. The different weights which allocated to grain size, Brazilian tensile strength and equivalent quartz content in study, improves the Schimazek index applicability in rock engineering applications specially rock cutting and drilling. Therefore, it is recommended to use new method instead of old one in future applications.










Keywords
abrasivity index has higher ability than old one. کلیدواژگان [English] rock
abrasivity
Schimazek index
cutting rate
1. Ataei M., Mikaiel R., Sereshki F., Ghaysari N., "Predicting the production rate of diamond wire saw using statistical analysis", Arabian Journal of Geosciences. 5 ((2011)) 1289-1295. 2. Ataei M., Mikaeil R., Hoseinie S. H., Hosseini S. M., "Fuzzy analytical hierarchy process approach for ranking the sawability of carbonate rock", International Journal of Rock Mechanics & Mining Sciences, 50 (2012) 83-93. 3. Buyuksagis I.S., Goktan R.M., "Investigation of marble machining performance using an instrumented block-cutter", Journal of Materials Processing Technology, 169 (2005) 258-262. 4. Buyuksagis I.S., "Effect of cutting mode on the sawability of granites using segmented circular diamond sawblade", Journal of Materials Processing Technology, 183 (2007) 399-406. 5. Chen Chao-Shi, Liu Ya-Ching, "A methodology for evaluation and classification of rock mass quality on tunnel engineering. Tunnelling and Underground Space Technology 22 (2007) 377-387. 6. Cheng Jao-Hong, Tang Chih-Huei, "An Application of Fuzzy Delphi and Fuzzy AHP for Multi-criteria Evaluation on Bicycle Industry Supply Chains", Wseas Transactions on System and Control. Issue 1, Volume 4, January (2009). 7. Cheng Jao-Hong, Tang Chih-Huei, Chih-Ming Lee, "An Application of Fuzzy Delphi and Fuzzy AHP on Evaluating Wafer Supplier in Semiconductor Industry",Wseas Transactions on System and Control. Issue 5, Volume 6, May (2009). 8. Ersoy A., Waller M. D., "Textural characterization of rocks", J. of Engineering Geology, June, VoL. 39, Issues 3-4 (1995a) 123-136. 9. Ersoy A., Atici U. "Performance characteristics of circular diamond saws in cutting different types of rocks", Diamond and Related Materials, 13 (2004) 22-37. 10. Ersoy A., Buyuksagis S., Atici U., "Wear characteristics of circular diamond saws in the cutting of different hard and abrasive rocks, Wear", 258 (2005) 1422-1436. 11. Eyuboglu AS., Ozcelik Y., Kulaksiz S., Engin IC., "Statistical and microscopic investigation of disc segment wear related to sawing Ankara andesites, Int. J. Rock Mech. Min. Sci. 40 (2003) 405-414. 12. Fener M., Kahraman S., Ozder M.O, "Performance Prediction of Circular Diamond Saws from Mechanical Rock Properties in Cutting Carbonate Rocks", Rock Mech. Rock Engng. 40 (5) (2007) 505-517. 13. Hoseinie S. H., Ataei M., Osanloo M., "A new classification system for evaluating rock penetrability", International Journal of Rock Mechanics & Mining Sciences 46 (2009) 1329-1340. 14. Kahraman S., Fener M., Gunaydin O., "Predicting the sawability of carbonate rocks using multiple curvilinear regression analysis", International Journal of Rock Mechanics & Mining Sciences, 41 (2004) 1123-1131. 15. Liu YC., Chen CS., "A new approach for application of rock mass classification on rock slope stability assessment", Eng Geol 89 (2007) 129-43. 16. Mikaeil R., Yousefi R., Ataei M., Abasian Farani R., "Development of a New Classification System for Assessing of Carbonate Rock Sawability", Archives of Mining Sciences, Vol. 56, No. 1 (2011a) 57-68. 17. Mikaeil R., Ataei M., Yousefi R., "The application of a fuzzy analytical hierarchy process to the prediction of vibration during rock sawing", Mining Science and Technology, 21 (2011b) 611-619. 18. Mikaeil R., Ozcelik Y., Ataei M., Yousefi R., "Ranking the sawability of dimension stone using Fuzzy Delphi and multi-criteria decision-making techniques", International Journal of Rock Mechanics & Mining Sciences; 58 (2013) 118-126. 19. Tutmez B., Kahraman S., Gunaydin O., "Multifactorial fuzzy approach to the sawability classification of building stones", Construction and Building Materials 21 (2007) 1672-1679. 20. Thuro K, "Drillability prediction- geological influences in hard rack drill and blast tunneling", Geol Runsch, 86 (1997) 426-438. 21. Wright D. N., Cassapi V.B., "Factors influencing stone sawability", Industrial Diamond Review, 2 (1985) 84-87. 22. Wei X., Wang CY, Zhou ZH., "Study on the fuzzy ranking of granite sawability", J. Mater. Process, Technol,139 (2003) 277-80.