Innovation and practice of efficient integrated tunneling and bolting in semi-coal rock roadways

The efficient and rapid excavation of semi-coal rock roadways is a major engineering challenge that needs to be addressed urgently in the mines with ten-million-ton productivity in Shaanxi-Inner Mongolia mining area. A series of technical issues, such as low cutting efficiency, non-parallel excavation and anchoring, low equipment reliability, and poor dust removal should be addressed. Based on the engineering application foundation of the “Coal Sea Dragon” rapid excavation equipment and coal-rock cutting experimental data, the cutting power was increased to 560 kW. Key structural components were strengthened and optimized, resulting in the successful development of a semi-coal rock bolter miner with an overall height as low as 2 m. To address the highly variable nature of coal-rock properties, an intelligent cutting system including adaptive cutting, planned cutting, and coal-rock recognition as its core functions was developed. The adaptive cutting system reduced cutting overload by approximately 15% and completely eliminated loads that exceeding 1.5 times the rated current. Research confirmed that rock cutting using a grooving method is the optimal process trajectory for semi-coal rock excavation. By optimizing the dust control parameters of the “three-stage” system, a 95% dust removal efficiency for semi-coal rock was achieved. Additionally, through the optimization of adaptive cutting parameters, vibration energy was reduced by up to 17%, laying the foundation for synchronous excavation and bolting operations in semi-coal rock conditions. A loading and conveying speed regulation system based on load perception was proposed, what not only met the demand for efficient transportation but also extended the service life of the semi-coal rock roadway loading and conveying system. An intelligent equipment management system based on multi-source information was developed. By integrating relevant professional knowledge databases and performing high-dimensional data fusion, the system achieved fault warning, analysis, prediction, and operational state playback, which strongly supported the equipment’s efficient and healthy operation. Industrial trials were conducted at the Zhujiamao Coal Mine, where the equipment withstood the challenge of rock hardness up to 73.2 MPa. The reliability of all intelligent systems was verified, and a monthly excavation record of 853 m in semi-coal rock was achieved, demonstrating the high efficiency of the semi-coal rock bolter miner.