New approach for rock-cuttability assessment using the edge-chipping test

Stefan Eberl

Research output: ThesisMaster's Thesis


The preliminary design of an underground mining or tunneling machine requires some knowledge about power and machine stability, which again requires the assessment of interaction forces between machine and rock. Thus, this topic becomes a major issue for machine manufacturers such as Sandvik Mining and Construction G.m.b.H. in Zeltweg/Austria. Since the 1980s, there exists the so-called edge-chipping test. This test is generally used for determining the edge toughness of brittle materials, e.g. ceramics and further more for prediction of specific energy for chip creation. In 1999, Dipl.-Ing. Dr. mont. Johann Tockner enhanced this laboratory index test to predict the above-mentioned interaction forces (cutting forces and normal forces) resulting from specific rock loading conditions during the cutting process. In his thesis, he achieved a good correlation between the results of his – so called “Kantenabbruchtest (edge-chipping test)“ and the results obtained from the radial cutting test rig. Due to the fact that the test equipment significantly improved in the last eleven years and the hydraulic press used for performing the index tests and the radial cutting test rig were adapted and modified, Sandvik wanted to check, if the old test results are still valid and can be used for today’s application. The first part of the present thesis deals with the practicability check of the edge-chipping test, whereby different rock types were tested. This part just covers the test itself and not the correlation with the cutting rig. The objective is to determine, if the former results can be reproduced and if the test set-up can still be used today or has to be improved regarding the use of modern state-of-the-art equipment. Additionally, some tool variation tests were performed in order to quantify the possible influence of tool geometry on cutting forces, crushing- and chipping energy, because the cutting forces mainly depend on tool geometry. The second part of the thesis covers the correlation between the results of the cutting rig and those of the edge-chipping test. First of all, the correlation values are calculated according to the original method using the new test results. Additionally, other possible correlation methods are developed and tested. Because Sandvik Mining and Construction G.m.b.H. Zeltweg/Austria also uses a linear cutting test rig for cutting force prediction of disc cutters, finally also these results are compared to the edge-chipping test.
Translated title of the contributionEin neuer Ansatz zur Beurteilung der Schneidbarkeit von Gestein mittels Kantenabbruchversuch
Original languageEnglish
  • Restner, Uwe, Supervisor (external), External person
  • Kargl, Hubert, Co-Supervisor (external)
  • Galler, Robert, Supervisor (internal)
Award date1 Jul 2011
Publication statusPublished - 2011

Bibliographical note

embargoed until 14-03-2016


  • Rock-cuttability
  • edge-chipping

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