Numerical Simulation Analysis of Concealed Tunnel Blasting Construction Impact on Adjacent Metro Stations

Objective The newly constructed hub station of Shenzhen Intercity Railway is connected to the east and west areas by a concealed tunnel under-crossing the existing metro station. To accelerate construction progress while ensuring safety, it is necessary to study the feasibility of blasting construction. Method A three-dimensional blasting excavation model of upper and lower steps is established using LSDYNA numerical simulation software, and the vibration effects of different blasting methods on the adjacent station are analyzed. Result ＆ Conclusion The numerical calculation results show that: The station bottom structure is significantly affected by the blasting disturbance; The upper step blasting causes great damage, with vibration velocity peak and maximum principal stress exceed the safety range, while the lower step blasting causes zero damage to the station bottom, the vibration peak is mostly within 1 cm/s, and the maximum principal stress is 0.26 MPa, both lower than the minimum dynamic tensile strength of C30 concrete 2.41 MPa; Since the groove section in the lower step blasting has a great impact on the station structure, it is recommended to combine controlled blasting measures, such as setting hollow holes and increasing the delayed detonation interval to ensure the construction safety. The research results provide a reference for actual constructions.