In a groundbreaking study that could reshape the future of underground construction, particularly in the energy sector, a team of researchers led by Dr. CHENG Xinjun from the Architecture and Civil Engineering Institute at Guangdong University of Petrochemical Technology has unveiled a novel approach to understanding the behavior of soil-immersed tunnels under seismic conditions. The research, published in the esteemed journal ‘Yantu gongcheng xuebao’ (Chinese Journal of Geotechnical Engineering), introduces a regional pushover method that considers soil dislocation, a factor often overlooked in conventional static pushover tests.
The study, conducted in collaboration with experts from the East China University of Technology, the China Earthquake Administration, and Guangzhou University, sheds light on the deformation and mechanical features of soils and immersed tunnels. “Our findings reveal that the immersed tunnel exhibits strong adaptability to soil deformation, thanks to the flexible joint,” Dr. CHENG Xinjun explained. This adaptability is crucial for the stability and safety of underground structures, especially in regions prone to seismic activity.
The research team conducted static pushover model tests on soil-immersed tunnels, focusing on the interaction between the soil and the tunnel structure. Their results showed that as soil dislocation increases, the earth pressure difference at the same depth of two tunnel elements near and away from the pushover plate can reach up to 71.6 kPa. This significant difference leads to obvious relative displacement between the tunnel elements, highlighting the importance of considering soil dislocation in seismic analysis.
One of the most compelling findings of the study is the identification of three distinct stages in the soil-immersed tunnel interaction: the soil compacting stage, the rapid development of differential deformation stage, and the joint failure stage. “During the joint failure stage, the soil-structure interaction coefficients near and away from the pushover plate are 3.10 and 0.67, respectively,” noted Dr. XU Kunpeng, a co-author of the study. This information is invaluable for engineers and architects designing underground structures, as it provides a clearer picture of how these structures behave under extreme conditions.
The implications of this research for the energy sector are profound. Immersed tunnels are often used for transporting oil, gas, and other energy resources across bodies of water. Ensuring the seismic safety of these tunnels is paramount for preventing catastrophic failures that could disrupt energy supplies and pose significant environmental risks. The study’s findings can provide experimental and technical support for the seismic analysis and risk assessment of immersed tunnels, ultimately leading to safer and more reliable underground infrastructure.
Dr. JING Liping, a co-author from the Institute of Engineering Mechanics at the China Earthquake Administration, emphasized the importance of this research for future developments in the field. “Our study offers a new perspective on the behavior of soil-immersed tunnels under seismic conditions. By understanding the interaction between soil and tunnel structures, we can design more resilient and adaptable underground infrastructure that can withstand the forces of nature.”
As the energy sector continues to expand and diversify, the demand for safe and efficient underground transportation of resources will only grow. The research conducted by Dr. CHENG Xinjun and his team represents a significant step forward in meeting this demand. By providing a deeper understanding of the mechanical behavior of soil-immersed tunnels, this study paves the way for innovative design and construction practices that can enhance the safety and reliability of underground infrastructure.
In the words of Dr. CUI Jie, a co-author from Guangzhou University, “This research is not just about improving our understanding of soil-immersed tunnels; it’s about building a safer and more sustainable future for the energy sector and beyond.” As the world grapples with the challenges of climate change and energy security, the insights gained from this study will be invaluable in shaping the future of underground construction and ensuring the resilience of our critical infrastructure.