Development of an experimental platform for coordinated rock breaking by multi-disc cutters in a tunnel boring machine

A full-face hard rock tunnel boring machine (TBM) is a large-scale, complex engineering system integrating mechanical, geotechnical, mining, and electrical engineering with control technology and intelligent sensing. Its cutterhead thrust, rotary drive, and disc cutter rock-breaking processes exhibit strong coupling, heavy loads, and complex dynamic responses. However, actual TBMs are large, expensive to manufacture and operate, and difficult to reproduce under conventional laboratory conditions, making repeatable, visualized, and measurable rock-breaking experiments challenging in teaching and research laboratories. This limitation hinders students’ understanding of TBM structural configuration, operating principles, and rock fragmentation mechanisms. To address this issue, this study develops a scaled experimental platform for collaborative rock breaking by multiple disc cutters in a full-face hard rock TBM, providing an effective experimental platform for mechanism research, engineering practice training, and intelligent mining equipment education.

The platform consists of a thrust system, a rotary system, a cutterhead–disc cutter mechanism, and a measurement and control system. The thrust system reproduces the process by which the TBM cutterhead applies thrust to the tunnel face during excavation, while the rotary system drives the cutterhead to rotate, enabling the disc cutters to roll, penetrate, and continuously break the rock surface. The cutterhead-disc cutter mechanism was designed according to scaled structural parameters to reproduce the collaborative rock-breaking process of multiple disc cutters under laboratory conditions. In addition, the platform is equipped with a multi-source sensing and measurement system incorporating vibration, load, and rotational speed sensors. This system synchronously acquires dynamic responses, load variations, and operating-state parameters during disc cutter rock breaking, providing data for subsequent signal processing, condition identification, and intelligent operation and maintenance research.

Rock-breaking experiments were conducted using the developed platform. The results showed that, under the combined action of thrust and rotary motion, the disc cutters produced continuous and distinct annular cutting traces on the rock surface, demonstrating that the platform can effectively simulate the rolling indentation and continuous rock-breaking process of TBM disc cutters. The experiments were stable and exhibited good observability and repeatability. More importantly, the platform enables the visualization and quantitative measurement of multi-cutter collaborative rock breaking. The collected vibration, load, and rotational speed data also provide a basis for analyzing rock-breaking load characteristics, vibration response patterns, and multi-source monitoring information.

The developed scaled experimental platform provides a practical and reproducible solution for research on TBM rock-breaking mechanisms and experimental teaching. It supports investigations of disc cutter rock-breaking mechanisms, load characteristics, vibration responses, multi-source signal processing, and intelligent operation and maintenance strategies. In addition, it can be used in experimental teaching for mechanical engineering, mining engineering, and intelligent equipment-related courses. Through this platform, students can better understand the structural configuration and operating principles of full-face hard rock TBMs, master the fundamental methods of experimental design, data acquisition, result analysis, and engineering communication, and strengthen their practical, analytical, and innovative abilities to solve complex engineering problems. Overall, the platform provides a valuable and transferable approach for talent cultivation in intelligent mining, experimental teaching reform, and research on the operating mechanisms of large-scale engineering equipment.