Mechanism and Treatment Technology of Three Water Inrush Events in the Jiaoxi River Tunnel in Shaanxi, China

Water inrush events in tunnels are geological hazards that pose a special engineering problem for tunnel construction in water-rich areas. To clarify the engineering background and hydrogeological conditions of water inrush in tunnels, this paper investigates and analyzes three incidents that occurred during the Jiaoxi River Tunnel Project. It analyzes the construction unit’s successful response to these events, presents their technical data, summarizes some practical high-value technology, and analyzes the mechanism of water inrush both qualitatively and quantitatively. It is found that the water source was the Jiaoxi River, and the water inrush channel was the concentrated leakage channel between the river and the tunnel. The prevention of water inrush is necessary for the excavation of tunnels that are prone to water inrush. In the event of a water inrush, plugging grouting is the most efficient water inrush treatment program. If grout plugging is to achieve better results, it must first fill the water inrush channel as completely as possible. Additionally, a distributary decompression holes—grouting posttreatment scheme is the improvement of the first two processing techniques, which deserves to be applied and popularized in practical projects.