Investigation of vibration patterns generated during rock cutting tests

Tunnel boring machines (TBMs) are essential for infrastructure projects and they should be operated in accordance with the geological conditions. Thus, swiftly recognizing and adapting to geological changes plays a critical role for the excavation. In that aspect, vibrations generated during excavation by TBMs have been analysed for ground identification in various studies. However, those measurements are often complicated by numerous influencing factors and noise sources, which make it challenging to isolate the specific effects of rock cutting on vibrations. Due to this reason, there is a need for a better understanding of vibrations created during the rock cutting process under controlled environment. With this aim, laboratory rock cutting tests are realized by a full-scale linear rock cutting machine equipped with a 17-inch disc cutter and accelerometers on three different rock samples with uniaxial compressive strength values ranging from 21 to 82 MPa. Peak, root mean square (RMS), and interval RMS accelerations are calculated from the recorded vibration data and the relations between vibrations, cutting performance parameters, cutting geometry, and mechanical properties of rocks are analysed. The results reveal that there is a relationship between cutting forces (especially average and peak normal force), rock mechanical and mineralogical properties, cutting configuration and vibrations. In general, it is possible to say that the vibrations increase as penetration and rock strength increase.