Abstract To compare the rock breaking mechanism of the tunnel boring machine (TBM) hob under traditional condition and free-face condition, a series of rock cutting tests and rock cutting simulations of the TBM hob under two cutting conditions are conducted. The rock chip, rock breaking forces and rock breaking efficiency etc. are investigated in this study. The research results denote that the rock chip size under the free-face is far larger than that under the traditional condition. Both the rock breaking forces and the rock breaking efficiency under the free-face condition could be reduced and be enhanced respectively compared with that under the traditional condition when the value of St and Sf ranges from 20 mm to 80 mm. Furthermore, the numerical and theoretical results also confirm the cutting rock under the free-face condition is promising, which can be applied to the water-jet TBM and the two-stage cutterhead TBM to improve the rock breaking performance of the TBM hob significantly.

中文翻译：

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传统与自由面条件下TBM滚刀破岩机理研究

摘要 为比较传统工况和自由面工况下隧道掘进机滚刀的破岩机理，对TBM滚刀在两种切削工况下进行了一系列岩石切削试验和岩石切削模拟。本研究对岩屑、破岩力和破岩效率等进行了研究。研究结果表明，自由面下的岩屑尺寸远大于传统条件下的岩屑尺寸。当St和Sf的取值范围为20~80 mm时，自由面条件下的破岩力和破岩效率均比传统条件下分别降低和提高。此外，数值和理论结果也证实了自由面条件下的切削岩石是有前途的，