Abstract: China's underground geotechnical engineering often faces complex geological conditions, such as high in-situ stress, subterranean karst, and extremely soft rock. These conditions can lead to loose and fractured rock structures, making it crucial for underground geotechnical engineering construction to quickly, accurately, and conveniently obtain rock mechanics parameters. We have autonomously developed the XCY-2 rotary cutting and penetrating system, a device for continuous monitoring of the drilling process. Various systems are integrated into this device, such as a power drilling control system, a comprehensive servo system, and an intelligent monitoring system. The installation process is straightforward, and the testing procedures are simple, facilitated by a human-computer interaction interface. To investigate the relationship between drilling parameters and the characteristic responses of different rock types during the rotary drilling process, we conducted comprehensive rotary drilling penetration tests under various conditions, including intact rock layers and layered rock masses, using the device and procedure. The test results showed that: 1) The intelligent monitoring system efficiently controls and monitors drilling parameters in real-time, including drilling speed, rotation speed, drilling torque, water pressure, drilling duration, drilling pressure, and drilling depth. This technology significantly facilitates high-precision drilling operations and continuous monitoring during underground construction. 2) When drilling through rock samples of various strength grades, we observed real-time fluctuations in drilling pressure and torque, while the drilling speed and rotation speed remained stable throughout the testing process. 3) Significant fluctuations in drilling torque and pressure were observed at the interfaces between different rock layers, indicating real-time perception of different rock types and achieving accurate positioning of rock layer interfaces. The XCY-2 rotary cutting and penetrating system provides a new approach for testing the physical and mechanical properties of underground rock masses.

Key words: rock mechanics, drilling equipment, rotary cutting and penetration technology, drilling parameter, rock formation identification