Theoretical and Experimental Results fom Laboratory Tests by ILCM

The intermediate linear cutting machine(ILCM) is a machine designed to work on anintermediate scale between the full- and the small-scale. The reduced scale involves several advantagescompared to full-scale tests, especially in terms ofsample supplying and transportation. On the otherhand, it has an impact on the testing conditions,resulting in a limitation of the cutting penetration andspacing during the test, as well as in a smaller disccutter. This affects most of the results, which cannot bedirectly used for the on-site machine performanceprediction. However, some experimental results provided in the literature show that the optimal spacing/penetration ratio is not significantly affected by thechanges involved. On this basis, the results obtainedfrom ILCM tests should provide reliable informationabout the optimal cutting conditions of a tunnel boringmachine in massive rock mass. The work performedincluded the development of some improvements ofthe testing rig, as well as a modified ILCM testingprocedure, according to the one typically used instandard LCM tests. The results provide informationabout the attitude of the tested lithotypes to mechanical excavation by means of disc tools, including theoptimal cutting conditions. Additional work wasdeveloped in terms of detailed characterisation of therock samples involved and assessment of the sizedistribution of the debris produced during the ILCMtests. Nevertheless, further tests are necessary, in orderto assess the consistency of the experimental procedure employed and to investigate the scale effect.