A Study on Cutter Wear and Mechanical Properties of Rocks in Tunneling with a TBM
Chikaosa TANIMOTO, Shunichiro YAMANAKA, Kimikazu TSUSAKA, Tatsuto NAKANE, Minoru HIRANO, Hiroshi KANZAKI, Suguru ABE and Shuichi IWATA
Abstract:Excessive cutter wear was ovserved 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. Key Words:TBM, Cutter discs, Cutter wear, Polarizing microscopic observation, Quartz contents, Shape of chips