Assessment of impact of performance parameters on TBM tool wear by use of silica samples

Excessive and unpredicted tool wear is one of the major challenges in mechanized excavation in tunnel projects.This problem, due to more demand for maintenance, increases excavation time in addition to cost overruns. For obtaining of a proper view about relation between performance parameters of the TBM and abrasivity, a new laboratory test machine is built in Engineering Geological Laboratory in Ferdowsi University of Mashhad, Iran. In this paper the results that achieved from performing tests on silica samples by the laboratory machine is presented. For this purpose 36 tests with various amount of surcharge and rotation speed at different times on coarse silica sand carried out. The obtained results have shown direct relation between test duration, surcharge and rotation speed versus weight loss. For example a direct linear relation between the tools wear and surcharge and/or rotation speed was observed. Indeed a logarithmic relation was gained for the time effect.