In the realm of tunneling and construction, the challenge of uneven wear on shield cutterheads and cutters has long been a thorn in the side of engineers and project managers alike. This issue is particularly pronounced in sand–pebble strata, where the abrasive nature of the terrain can lead to significant downtime and increased costs due to frequent maintenance. However, a groundbreaking study published in ‘Yantu gongcheng xuebao’ (translated to ‘Rock and Soil Mechanics’) by a team led by ZHANG Jinxun from Beijing Urban Construction Group Co., Ltd., and JIANG Yusheng from China University of Mining and Technology-Beijing, offers a promising solution to this persistent problem.
The research team has developed a novel method for calculating wear on cutters based on friction and wear principles, leading to the establishment of theories and design methods for achieving uniform wear of shield cutters. This innovation is set to revolutionize the way tunneling projects are approached, particularly in the energy sector where underground infrastructure is crucial.
“By designing different cutterhead alignments and arranging a specific number of cutters on each trajectory radius, we can achieve uniform wear of the entire set of cutters,” explains ZHANG Jinxun, the lead author of the study. This uniformity not only extends the life of the cutters but also significantly reduces the tool wear coefficient of the outer ring of the cutterhead, allowing for longer continuous excavation periods without the need for cutter changes.
The implications for the energy sector are substantial. Tunneling projects, such as those involved in the construction of pipelines, underground power lines, and energy storage facilities, often face delays and budget overruns due to the wear and tear of tunneling equipment. The ability to predict and mitigate wear can lead to more efficient project management, reduced costs, and improved safety.
The study also introduces the concept of the “circumferential knife index β” and “formation lithology index n,” which are critical factors in the design of shield cutterheads and cutters for uniform wear. For conventional shields with a radius between 2.5 m and 6 m, the researchers found that the optimal range for β is between 1.83 and 2. For larger shields with a radius of 6 m or more, a flat cutterhead design is recommended, with a specific number of cutters arranged on each trajectory.
The research team validated their findings using EDEM particle flow numerical software, creating a model for a sand–pebble stratum 6.6 m in depth. The results confirmed the effectiveness of their uniform wear design, showcasing a significant reduction in wear differences among the cutters and an extended maximum continuous excavation distance.
As the energy sector continues to expand and diversify, the demand for efficient and reliable tunneling technologies will only grow. This research not only addresses a critical challenge in the field but also paves the way for future innovations in tunneling and construction. By adopting these new design methods, engineers can enhance the durability and performance of their equipment, ultimately driving progress and efficiency in the energy sector.
In the words of JIANG Yusheng, “This study represents a significant step forward in our understanding of wear mechanics in tunneling. It provides a robust framework for designing cutterheads and cutters that can withstand the rigors of sand–pebble strata, ensuring smoother and more cost-effective tunneling operations.”
As the construction industry continues to evolve, the insights gained from this research will undoubtedly shape the future of tunneling, making it more efficient, economical, and environmentally friendly. The publication of this study in ‘Yantu gongcheng xuebao’ marks a milestone in the field, offering a beacon of hope for engineers and project managers grappling with the challenges of tunneling in abrasive terrains.