Decomposition and separation of vibration waves from blasting demolition of tall buildings and their component characteristics

Blasting demolition is widely used to remove large structures, but the resulting ground vibration can threaten nearby buildings and underground facilities. This vibration arises from explosive detonation and structural impact during collapse, giving it source mechanisms, wave components and attenuation behaviours that differ from those of underground blasting. Conventional peak and frequency indices cannot fully identify these contributions. In this study, a wave component characterisation method based on three dimensional polarisation states is developed to separate blast vibration waves from collapse vibration waves and analyse compressional, shear and Rayleigh waves during building blasting demolition. A normalised dominance factor is proposed to quantify wave type dominance and its transition during propagation. Here, we show that blast vibration waves exhibit staged changes in dominant wave components during initiation, whereas collapse vibration waves are controlled more strongly by shear and Rayleigh waves, supporting refined evaluation and control of blasting demolition vibration. This study introduces a three-dimensional polarisation analysis method to deconstruct vibration waves from building blasting demolition, enabling separation of P, S, and R waves. Results reveal stage- and direction-dependent wave dominance, improving assessment and control of vibration hazards.