Investigating spectral behavior of tunnel blast-induced vibration using wavelet analysis: a case study of a dam in China

Abstract

Blast-induced vibration with non-stationary behavior needs specific tools to be analyzed. We explore the capability of wavelet analysis to investigate the blast-induced vibration characteristic of a dam in China. Velocity sensors are installed on the bedrock as well as the crest to record particle vibration response subject to an adjacent tunnel blasting. Finite element method (FEM) is adopted to determine the natural frequencies and mode shapes of the dam, as well as the time-history dynamic response. The continuous wavelet transform and discrete wavelet multi-resolution analysis enable us to characterize the peak particle velocity (PPV), spectral energy and vibration duration more specifically. Cross wavelet transform and wavelet coherence present the advantage to give the common power and phase-locked behavior between bedrock records and crest records. No evidence of resonance is found in the phase relations where the dam’s natural frequency is located. All the results including FEM, PPV, spectral energy and displacements are matching and indicate that the dam is in the undamaged state.