Abstract: Rock breaking by disc cutter is a fundamental mechanical behavior in tunnel boring machine (TBM) tunnelling. Scholars have conducted extensive studies on rock-breaking theories, but systematic comparisons between the theoretical tunnelling parameters and experimental results are rarely reported. This study presents theoretical and experimental studies on TBM disc cutter rock breaking. First, three types of theoretical models, i.e., compressive rock breaking, compressive-shear rock breaking, and compressive-tensile rock breaking, are reviewed, and the expressions for normal force and rolling force in seven classical calculation models (Evans, Roxborough, Wijk, SJTU, CSM, Sanio, and NEU models) are summarized. Leveraging a self-developed TBM tunneling comprehensive test platform, laboratory tunnelling tests were conducted on low-, medium-, and high-strength sandstones, with key parameters such as cutterhead thrust, torque, and displacement obtained. By comparing theoretical calculations with experimental results, it was found that the CSM model performed best in both thrust and torque calculations, with deviations controlled within 26%, making it the preferred model. The Evans and NEU models generally yielded lower values than experimental results and were suitable for preliminary estimations, making them the second-best recommended models. The Roxborough, Wijk, SJTU, and Sanio models exhibited deviations exceeding 100%, necessitating adjustments in accordance with specific engineering conditions, thereby rendering them as alternative models. This study reveals the influence of rock strength on model applicability, providing theoretical references for TBM tunnelling parameter prediction and rock-breaking mechanism research.

Key words: tunnel boring machine (TBM), disc cutter rock breaking, theoretical model, tunnelling test