Analysis of a Water Inrush Accident in a Deep Foundation Pit Caused by an Abandoned Pile and Its Treatment Measures

In this paper, the previous construction process, water inrush conditions, mechanism of water inrush, and accident treatment measures of abandoned pile 204# of the Jiangbei Central Business District (Jiangbei CBD) in Nanjing, China, are introduced in detail. This accident is an underground confined water inrush caused by construction disturbance and water level changes after the bored pile runs through the waterproof layer. Although this kind of accident is relatively rare, it can cause large losses and is difficult to treat. This paper analyzes the inrush of local soil from the perspective of hydraulic fracture and provides some ideas for scholars to evaluate inrush in underground engineering by means of mechanical analysis or numerical models. The treatment of the Rodin jet pile method after water pressure reduction proved effective and had little influence on the buildings, indicating it as an effective method for the treatment of this kind of accident.