In the bustling world of urban infrastructure, where cities are constantly evolving and expanding, the construction of rail transit systems has become a critical component. As China’s urban rail transit networks grow, so do the challenges faced by engineers and construction professionals. One such challenge is the excavation of deep foundation pits for station construction, a process that demands precision, efficiency, and cost-effectiveness. Enter Cao Yu, a researcher from the Construction Branch of Ningbo Rail Transit Group Co., Ltd., who has been delving into the complexities of diaphragm wall grab trenching, a crucial technique in this domain.
Cao’s recent study, published in *Chengshi guidao jiaotong yanjiu* (translated as *Urban Rail Transit Research*), focuses on the thrust resistance encountered during grab trenching, a factor that significantly impacts construction costs and efficiency. “The direct object of diaphragm wall grab trenching is the soil,” Cao explains. “The excavation resistance encountered by the grab in different soil layers directly affects the construction costs and trenching quality and efficiency.”
Traditionally, research in this area has been sparse and often focused on other engineering fields, such as river dredging. Cao’s work stands out because it comprehensively considers the impact of soil accumulation and slurry pressure within the grab on thrust resistance. By analyzing the failure, movement, and accumulation characteristics of soil during excavation, Cao has developed an improved calculation model using the plastic limit analysis method. This model introduces the soil accumulation angle and slurry pressure, providing a more accurate prediction of thrust resistance.
The practical implications of this research are substantial. Accurate calculation of thrust resistance can lead to more efficient and cost-effective construction processes. As Cao notes, “The error between the calculated results of thrust resistance during grab excavation by the constructed model and the experimental results is -0.55%.” This high degree of accuracy not only validates the model but also underscores the importance of considering soil accumulation and slurry pressure in grab trenching operations.
For the energy sector, which often involves large-scale construction projects, this research offers valuable insights. Understanding and mitigating thrust resistance can enhance the efficiency of foundation work, reducing both time and financial investments. As urbanization continues to surge, the demand for reliable and efficient construction techniques will only grow, making Cao’s work a timely and relevant contribution to the field.
Cao’s research is a testament to the power of targeted scientific inquiry in solving real-world problems. By addressing the specific challenges of diaphragm wall grab trenching, Cao has provided a tool that can improve construction practices and contribute to the sustainable development of urban infrastructure. As cities continue to expand and evolve, the insights gained from this study will undoubtedly play a crucial role in shaping the future of urban rail transit and beyond.