In the heart of Guangzhou, where urban development meets geological complexity, a groundbreaking study is reshaping how we approach deep foundation pits. Led by Lianyan Jia from the School of Civil Engineering, this research delves into the deformation characteristics and control measures for deep excavations in soil-rock composite strata, offering critical insights for the construction and energy sectors.
Guangzhou’s unique geological conditions present a challenge for engineers. The city’s varying thickness of soft soil layers demands precise control over excavation deformations to ensure the safety of adjacent structures and the stability of the excavation itself. Jia’s study, published in the journal Advances in Civil Engineering, (translated from Chinese as Advances in Civil Engineering) sheds light on how to navigate these complexities.
The research focuses on a metro station excavation, using field measurement data to analyze the relationship between maximum deformation and various influencing factors. “We found that the maximum lateral displacement of support structures typically ranges from 15 to 30 millimeters,” Jia explains. “Vertical ground deformations, on the other hand, range from 0.86‰ to 2.35‰ of the excavation depth.”
One of the key findings is the impact of the insertion ratio of support structures. Increasing this ratio improves stiffness and reduces surface settlement. However, there’s a sweet spot. “When the base of the support structure is embedded in the load-bearing rock layer and the insertion ratio exceeds 0.25, further increases yield diminishing returns in controlling surface settlement,” Jia notes.
The study also reveals that both vertical ground deformations and lateral displacements of support structures are positively correlated with excavation depth. However, they are negatively correlated with the length-to-width ratio, width-to-depth ratio, and insertion ratio of the excavation. These insights are crucial for optimizing construction measures and protecting adjacent structures.
So, what does this mean for the future of construction and the energy sector? As cities continue to expand and infrastructure projects delve deeper, understanding and controlling deformation in complex geological conditions will be paramount. This research provides a roadmap for enhancing the stability of deep excavations, ensuring the safety of surrounding structures, and optimizing construction processes.
For the energy sector, this research is a game-changer. Many energy projects, such as underground power plants or energy storage facilities, require deep excavations. The insights from this study can help mitigate risks, reduce costs, and improve the efficiency of these projects. Moreover, as renewable energy projects often require extensive underground infrastructure, this research can aid in the development of sustainable energy solutions.
The study also underscores the importance of data-driven decision-making in construction. By leveraging field measurement data and statistical analysis, engineers can make more informed decisions, leading to safer and more efficient construction processes.
As we look to the future, this research by Lianyan Jia and his team at the School of Civil Engineering sets a new standard for deep excavation practices. It’s a testament to the power of scientific inquiry in solving real-world problems and paving the way for sustainable urban development.