Power flow analysis of subway-induced vibration transmission in superstructures

Urban subway provide convenient transportation but induce unavoidable vibrations, particularly in superstructures. Based on power flow theory, this research investigates the propagation characteristics of vibration energy in superstructures induced by subway operations. Field measurements of subway-induced vibrations and a 3D finite-element model are developed, with train loading parameters iteratively calibrated to match measured and simulated results. Using these refined subway loading parameters, the superstructures’ vibration is calculated and analyzed via power flow theory to determine the vibration energy propagation law, transmission path and beam-column energy distribution. Results show attenuation rates of 21.3% for floors 1-2, 14.4% for floors 3-12, and increased attenuation rates (20% and 40.8%) at floors 13-14 due to energy reflection. At the beam-column node, the beam shares 25.5% of the energy – on average – and the column shares 74.5%.