Blast-induced ground vibration propagation and prediction in a sandstone slope with soft mudstone interlayer

Abstract

Accurate prediction of blast-induced vibration propagation in rock slopes is critical for ensuring safe and efficient excavation, particularly in geologically complex settings where soft mudstone interlayers fundamentally modify vibration attenuation mechanisms. This study presents an integrated methodology combining field-scale blast experiments, advanced dynamic finite-element simulations, and wavelet packet energy analysis to systematically evaluate how varying dip angles and thicknesses of soft mudstone interlayers govern vibration transmission patterns and spectral energy redistribution in rock slopes. The in situ blasting test focuses on the Pinglu Canal Qingnian Hub project, where multi-point vibration monitoring was implemented across rock slope profiles. A dimensional analysis-driven predictive framework was formulated to quantify interlayer geometric effects on vibration velocity propagation. The results demonstrate three critical insights: First, vertical vibration components consistently exhibit dominant characteristics, manifesting the highest peak velocities and predominant frequencies across all monitored locations. Second, increasing soft mudstone interlayer inclination angles and thicknesses significantly amplify vibration attenuation rates along slope surfaces while inducing notable energy redistribution – enhanced dissipation of high-frequency vibrational components coupled with increased proportional contributions from low-frequency bands. This frequency-dependent energy transformation mechanism elevates resonance risks as spectral characteristics progressively align with slope structures’ intrinsic vibrational modes. Third, the developed prediction model effectively generalizes the relationship between changes in the thickness and dip of the soft mudstone interlayer and the blast-induced vibration velocity, and compares it with the classical Sadowski’s formula with much improved accuracy. By establishing quantitative relationships between soft mudstone interlayer configurations and vibration transmission behaviors, this research advances fundamental understanding of soft mudstone interlayer while providing actionable guidelines for optimizing blast designs in interlayered rock masses.