A Study on Cutter Wear and Mechanical Properties of Rocks in Tunneling with a TBM

Abstract

Excessive cutter wear was observed in tunneling with a TBM through the sandstone layers of the Mesozoic era in the Shimanto Belt. Generally, it causes not only the additional cost of cutter discs but also the additional time to replace them. The authors investigated the mechanical properties of rocks, quartz contents and shape of chips through the unconfined compression test, point load test and polarizing microscopic observation in order to clarify the relationships among the cutter wear and the geological properties. In conclusion, the excessive cutter wear was caused by the sandstone with high quartz contents and hard matrix. Additionally, it was found that the chip shapes were comparatively thin and wide in chippings through the hard rock which excessively wore cutter discs and the flatness was also higher with quartz contents.