Hydraulic characteristics of a deep tunnel system under different inflow conditions

作者：Chao Yu, Xiaodong Yu, Jian Zhang, Yiran Wang, Hui Xu · 发表于：Physics of Fluids · 年份：2024 · DOI：10.1063/5.0240078 · 被引用次数：5 · 研究领域：Hydraulic flow and structures、Geotechnical Engineering and Underground Structures、Dam Engineering and Safety

Deep tunnel systems are characterized by large burial depths, long distances, and free-surface pressurized flows, operating under complex inflow conditions that can lead to strong pressure oscillations, particularly in the transitions between the main tunnel and shafts. This paper focuses on the deep tunnel system in Shanghai, China. A physical model was established based on the gravity similarity, and a corresponding one-dimensional mathematical model for free-surface and pressurized flows was established. The entire process of water inflow was observed in the experiment, and several inflow conditions, including different discharge and inflow schemes, were conducted to analyze the maximum pressure at the junction between shaft and deep tunnel, as well as the pressure along the tunnel. The deviation degree was introduced to validate the reliability of the numerical model. The impact of inflow distribution on deep tunnel pressure was studied with numerical simulation. The results indicated that simultaneous inflow from both shafts leads to a more pronounced phase difference. The pressure downstream after stabilization was higher than the pressure upstream. Simulations of pressure variations with the same discharge under different inflow scenarios revealed that symmetric inflow results in higher pressure at both the midpoint of the tunnel and in front of the downstream shaft. Asymmetric inflow only creates localized high pressure in front of the downstream shaft, with symmetric...