In the bustling heart of Chengdu, a groundbreaking study is reshaping how we approach urban rail transit construction, with significant implications for the energy sector. Dr. Jiang Jianjun, from the School of Electrical Automation and Information Engineering at Tianjin University, has been leading a pioneering investigation into the control of railway subgrade deformation during shield tunnel construction. His work, published in the journal ‘Chengshi guidao jiaotong yanjiu’ (translated to ‘Urban Rail Transit Research’), is set to revolutionize the way we think about underground infrastructure projects.
The challenge is clear: as cities expand, so does the need for efficient public transportation. However, constructing shield tunnels beneath existing railway subgrades can lead to unwanted settlement, posing risks to both the new tunnel and the operational railway. Dr. Jiang’s research focuses on the use of pipe roof support methods to mitigate these risks, ensuring safer and more efficient construction processes.
At the core of Dr. Jiang’s study is the use of advanced numerical simulations and on-site monitoring data. “The key is to find the optimal layout and spacing of the pipe roof support,” Dr. Jiang explains. “By doing so, we can significantly reduce subgrade settlement and segment displacement, ensuring the stability of both the new tunnel and the existing railway.”
The study, which involved a case study of Chengdu Metro Line 5 underpassing a railway subgrade, proposed a double-layer pipe roof support scheme. Using FLAC 3D software, Dr. Jiang and his team simulated various circumferential layout scopes and spacings, evaluating their impact on the tunnel’s surrounding rock plastic zone, subgrade settlement, and segment displacement.
The results are striking. For general strata, the researchers found that a pipe roof layout covering a 150° arch part circumferential scope with a 40 cm spacing can meet segment displacement control requirements. Moreover, when the circumferential spacing was reduced to 30 cm and the arch angle increased from 90° to 180°, the maximum subgrade settlement decreased dramatically from 50.00 mm to just 2.50 mm, well below the warning value of 3.75 mm. This optimal layout also minimized the volume of the surrounding rock’s plastic zone and segment displacement, aligning perfectly with settlement warning value requirements.
The commercial impacts of this research are profound. For the energy sector, which often involves complex underground infrastructure, these findings offer a blueprint for safer and more efficient construction. By minimizing settlement and displacement, energy companies can reduce maintenance costs, enhance operational safety, and accelerate project timelines.
Looking ahead, Dr. Jiang’s work is poised to shape future developments in the field. “Our findings provide a solid foundation for further research and practical applications,” he notes. “As urbanization continues to grow, so will the demand for safe and efficient underground construction methods. This study is a significant step forward in meeting that demand.”
As cities continue to grow and evolve, so too must our approach to infrastructure development. Dr. Jiang Jianjun’s research, published in ‘Urban Rail Transit Research’, offers a compelling vision of the future, one where technology and innovation converge to create safer, more efficient, and more sustainable urban environments. The energy sector, in particular, stands to gain significantly from these advancements, paving the way for a new era of underground construction.
