Entwicklung eines Modellversuchs zur Schneidbarkeitsermittlung von Hartgestein

Translated title of the contribution: Development of a model experiment for estimation of the cutability of hard rock

Stefan Lorenz

Research output: ThesisMaster's Thesis


The estimation of penetration is an important basis for the determination of performance prediction for tunnel boring machines (TBM). The currently used performance prediction models are largely based on results from standard geotechnical tests which results in significant differences in performance prediction. Experiments like the uniaxial compressive strength or the indirect tensile strength cannot replicate the failure mechanism by disc cutters when cutting the tunnel face, so they are limited for use in prediction models. Results of cutting tests in the scale of 1 to 1 can reproduce the chipping mechanism more accurate, but for these experiments own test rigs are required and large samples sizes are needed. In this work experimental equipment has been developed to replicate the cutting process with disc cutters by tunnel boring machines (TBM) in a small scale rock cutting test. The aim is to determine an easy to handle test rig for measuring cutting forces during the rock cutting process. For the small scale rock cutting test a rig which is suitable for the installation in hydraulic presses, available in rock mechanics laboratories, was designed. In a first phase design requirements such as the use of a model disc cutter, the variation of the penetration and the ability to adjust cutter spacing were considered. In the further phases all machine elements were dimensioned according to the working load, a three-dimensional model was created and the scaled test rig was fabricated. In order to evaluate the quality of the test rig, results of the experiments with the small scale cutting test are compared to results of the linear cutting tests at the Colorado School of Mines (CSM). The analysis shows similar behavior regarding cutting forces. This leads to the conclusion that the technical expertise of the developed scaled rock cutting test is practical for the use in penetration models very well.
Translated title of the contributionDevelopment of a model experiment for estimation of the cutability of hard rock
Original languageGerman
  • Galler, Robert, Supervisor (internal)
  • Entacher, Martin, Co-Supervisor (internal)
Award date22 Mar 2013
Publication statusPublished - 2013

Bibliographical note

embargoed until null


  • scaled cutting test
  • penetration prediction
  • cuttability
  • hard rock

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