Research on Metro Vibration Monitoring and Its Impact on the Extraction of Noise Surface Wave Dispersion Curves

This study investigates the impact of subway vibrations on surface wave dispersion curve extraction using urban background noise. Four observation points at varying distances from the Changping Subway Line were monitored for 5 days using Smartsolo three-component seismometers. Spectral and energy density analyses of segmented signals (subway peak, off-peak, and non-operational periods) revealed significantly elevated waveform spectral amplitudes during subway operation. Micro SPAC and linear array configurations were deployed to compare dispersion curve quality across different distances and operational phases. Results demonstrate that dispersion curve extraction quality inversely correlates with proximity to the subway line, with closer points showing poorer performance. Data from subway off-peak periods exhibited optimal scattering characteristics for dispersion analysis. These findings provide practical insights for urban seismic noise data processing in surface wave method applications.