Aspects of <scp>TBM</scp> cutterhead design and performance in very hard rock mass

Abstract Tunnel boring machines (TBMs) have revolutionized underground excavation, offering efficient, and cost‐effective solutions for tunneling projects worldwide. With an increasing demand for tunnels in geologically challenging or very hard and abrasive conditions, understanding the critical aspects of cutterhead design and its impact on TBM performance is crucial for successful tunneling operations. Little experience is documented on the performance and durability of TBM operating in “very hard” rock conditions. An unbiased performance quantification is established based on a shared understanding of hard rock conditions. The actual design of TBMs demands can only cover certain aspects of TBM–rock mass interaction, demanding further adoption and improvements of primary and secondary wear.