In the bustling world of urban infrastructure, the construction of metro systems is a critical endeavor that demands precision and safety. A recent study published in ‘Chengshi guidao jiaotong yanjiu’ (Urban Rail Transit Research) sheds light on the mechanical response of tunnel structures during the construction of connecting passages in metro shield intervals. Led by DU Mingfang of the College of Civil Engineering at Henan University of Technology in Zhengzhou, China, the research delves into the intricate forces at play during this complex process.
The study focuses on the mechanical method of pipe jacking construction, a technique used to create connecting passages between metro tunnels. This method, while efficient, can significantly impact the internal forces within the segment structures of the mainline tunnels. Understanding these forces is crucial for ensuring the safety and longevity of the tunnel structures.
DU Mingfang and his team utilized ABAQUS finite element software to create a numerical calculation model. This model simulated the entire construction process of a connecting passage in a Zhengzhou Metro shield interval. The goal was to investigate the deformation of the mainline tunnel structure and the changes in internal forces during construction.
The results were compelling. The simulation revealed that the maximum deformation of the cutting ring—a critical component in the construction process—exhibts a gradually increasing trend. The maximum bending moment at the originating end of the cutting ring first increases and then decreases, while at the receiving end, it initially decreases slowly before increasing. The maximum axial force of the cutting ring shows a consistent upward trend.
“These findings are crucial for understanding the mechanical behavior of tunnel structures during the construction of connecting passages,” DU Mingfang explained. “By identifying the weak points and force variation patterns, we can ensure the safety and stability of the tunnel structures, which is essential for the long-term reliability of metro systems.”
The study’s implications extend beyond immediate safety concerns. As cities continue to expand and metro systems become more complex, the ability to predict and manage the mechanical responses of tunnel structures will be vital. This research provides a robust framework for future developments in the field, offering insights that could shape the design and construction of metro systems worldwide.
The commercial impacts for the energy sector are also significant. Efficient and safe metro systems can reduce the reliance on fossil fuels by providing a reliable and sustainable mode of transportation. By ensuring the structural integrity of these systems, the research contributes to the broader goal of creating more energy-efficient and environmentally friendly urban environments.
The study’s validation of the numerical model through comparison with actual measured values underscores its reliability. This validation is a testament to the accuracy of the finite element model and its potential for future applications in similar construction projects.
As the demand for efficient and safe metro systems continues to grow, research like DU Mingfang’s will play a pivotal role in shaping the future of urban infrastructure. By providing a deeper understanding of the mechanical responses during construction, this study paves the way for more innovative and reliable solutions in the field.