A New Zealand Geotechnical Society Symposium paper. I believe you will find it interesting. Open Access article. No paywall.

These findings will enable a better correlation between TBM performance and geological conditions for use in TBM design, as a basis for contractual payments where penetration rate dominates the excavation cycle and in further academic investigations into the TBM excavation process.

Using Tunnel Boring Machine Penetration Tests to Quantify Performance in Hard Rock

https://www.nzgs.org/libraries/nzgs20_villeneuve/