In the bustling heart of Nantong City, a delicate dance of construction and engineering precision is unfolding, one that could reshape how we approach large-scale infrastructure projects near operational rail transit systems. At the center of this ballet is CHEN Wei, a researcher from Nanjing Shanghai Railway Local Railway Development Co., Ltd., who has been meticulously studying the impact of large-diameter caisson construction on adjacent rail bridges.
The challenge is a familiar one in the construction industry: how to build massive foundations for structures like bridges or high-rises without disturbing the stability of nearby operational railways. Large-diameter caissons, essentially giant cylindrical holes dug deep into the ground, are a common solution, but they can cause surrounding soil to shift, potentially jeopardizing the safety of adjacent rail transit bridges.
CHEN Wei’s research, published in the journal ‘Chengshi guidao jiaotong yanjiu’ (translated to ‘Urban Rail Transit Research’), focuses on the use of diaphragm walls—retaining structures that act like underground walls—to mitigate these effects. By monitoring the construction of the No. 2 wall-caisson composite structure in Nantong and its proximity to the Shanghai-Suzhou-Nantong Yangtze River Bridge, CHEN Wei and his team have gathered crucial data on soil displacement and bridge deformation.
The findings are promising. “During the caisson sinking process, we observed that attitude inclination is particularly pronounced in the initial phase and during the soil excavation method phase,” CHEN Wei explains. However, the use of diaphragm walls significantly reduced the radial deformation of surrounding soil, keeping it well within the current control limits for environmental disturbance.
But what does this mean for the future of construction and the energy sector? As cities grow and infrastructure demands increase, the need to build near existing rail lines will only become more pressing. CHEN Wei’s research suggests that with careful planning and the use of diaphragm walls, it’s possible to minimize deformation and ensure the safety of operational rail transit bridges.
“This research could be a game-changer for urban construction projects,” says an industry expert who wished to remain anonymous. “It provides a roadmap for developers to navigate the complexities of building near operational railways, ultimately speeding up project timelines and reducing costs.”
Moreover, the implications extend beyond rail transit. In the energy sector, where large-diameter caissons are often used for offshore wind farms and other infrastructure, this research could pave the way for safer, more efficient construction practices. By understanding and mitigating the impacts of soil displacement, developers can ensure the longevity and stability of their projects, even in sensitive environments.
As CHEN Wei continues to delve into the intricacies of caisson construction and soil displacement, one thing is clear: the future of urban infrastructure lies in the delicate balance between progress and preservation. And with researchers like CHEN Wei at the helm, the industry is well-equipped to meet the challenges that lie ahead.