In the heart of China, where expansive loess plateaus meet the demands of modern infrastructure, a team of researchers from Chang’an University has made a significant stride in tunnel engineering. Led by LUO Yanbin, a group of academics has developed a novel method for calculating the pressure of surrounding rock in loess tunnels, a critical advancement that could reshape how we approach tunnel construction in similar geological conditions worldwide.
Loess, a unique type of sediment found in various parts of the world, including China, the United States, and parts of Europe, has long posed challenges for engineers. Its porous and friable nature makes it prone to deformation, complicating the calculation of surrounding rock pressure—a crucial factor in ensuring the stability and safety of tunnels.
The team’s research, published in the Chinese journal ‘Yantu gongcheng xuebao’ (translated to English as ‘Rock and Soil Engineering’), analyzed a vast amount of field test data to identify the key impact factors influencing surrounding rock pressure in loess tunnels. They found that the pressure is primarily a result of deformation, a factor often overlooked by conventional calculation methods based on the loosening theory.
“Our findings indicate that the surrounding rock pressure in loess tunnels is significantly affected by the grade of surrounding rock, burial depth, span, and the height-span ratio of excavation,” said LUO Yanbin, the lead author of the study. “These factors exhibit a good exponential function correlation with the surrounding rock pressure, which has not been adequately addressed in existing calculation methods.”
The researchers developed a new calculation formula using a multi-factor coupled regression analysis method and a sample enveloped method combined with a trial algorithm. This formula, they argue, provides a more accurate reflection of the load situation in loess tunnels compared to commonly used methods like Terzaghi’s formula, the Code for Design of Tunnels, and Caquot’s formula.
The implications of this research are substantial, particularly for the energy sector. As the world increasingly turns to renewable energy sources, the need for efficient and safe infrastructure to transport and store energy becomes paramount. Loess regions, with their vast expanses and unique geological features, could play a pivotal role in this transition. However, the successful construction of tunnels for energy transportation and storage in these regions hinges on a deep understanding of the surrounding rock pressure.
“Our method provides a more accurate and reliable way to calculate the surrounding rock pressure in loess tunnels,” said LUO Yanbin. “This could lead to safer and more cost-effective tunnel construction, ultimately facilitating the development of energy infrastructure in loess regions.”
The research also opens up new avenues for future studies. As LUO Yanbin noted, “While our method shows promise, further validation and refinement are needed. We hope our work will inspire more research in this area, ultimately contributing to the advancement of tunnel engineering in loess regions.”
In the ever-evolving landscape of construction and energy, this research stands as a testament to the power of innovation and the potential of interdisciplinary collaboration. As we strive to build a more sustainable future, understanding and harnessing the unique challenges and opportunities presented by loess regions could be a game-changer. And with the work of LUO Yanbin and his team, we are one step closer to unlocking that potential.