Abstract: To control the risk of an earth pressure balance shield obliquely tunneling underneath an adjacent existing metro station in a curved receiving section and a waterrich gravel stratum, a case study is conducted on the Nanning rail transit line 5 crossing beneath the Guangxi University station of the existing line 1, and the construction risks of the existing station structure are analyzed using the methods of current situation investigation, numerical simulation, and field measurement. Subsequently, a finite element software MIDAS GTS NX is used to establish a threedimensional numerical model to predict the influence of stress and deformation on the existing station and entrance. The early warning control value is proposed combining automatic and manual monitoring, and the shield construction parameters are dynamically adjusted through relevant technical schemes and measures, such as plain pile reinforcement, stratum reinforcement, pile wall cutting, chamber opening and cutter changing, and well group dewatering. Finally, successful shield crossing underneath the existing station is achieved, thereby ensuring the safe operation of the existing line.

Key words: shield tunnel, obliquely crossing, existing station, numerical simulation, structural deformation, monitoring