The propagation characteristics and prediction of vibration induced by horizontal-hole blasting in soil-rock strata

Clarifying the blasting vibration characteristics in soil-rock strata is a critical prerequisite for controlling the effects of blast-induced vibrations. Based on an underground blasting project in a typical urban soil-rock stratum，a model test of horizontal-hole blasting in soil-rock strata was designed and conducted. Combined with finite element numerical methods，the influence of the blasting source and site conditions on the propagation laws of blast-induced vibrations in soil-rock strata was analyzed. Finally，a predictive model for blasting vibration in soil-rock strata was established based on dimensional analysis. The results show that the soil-rock interface exhibits high-frequency filtering characteristics，while the free surface shows a vibration amplification effect. The R-wave develops in the direction away from the epicenter，resulting in a segmented attenuation characteristic of the vibration velocity at the free surface. Increasing the burial depth of the blasting source suppresses the attenuation of vibration velocity across discontinuities，weakening energy dissipation at the soil-rock interface and site amplification effects. Increasing the wave impedance ratio of the rock and soil slows down the attenuation of vibration velocity at the soil-rock interface，while accelerating energy dissipation at the interface and vibration velocity attenuation at the free surface，thus enhancing site amplification effects. Increasing the soil thickness does not affect the vibration characteristics at the soil-rock interface but promotes vibration velocity attenuation at the free surface，suppressing site amplification effects. Under small-angle assumptions，the dip angle of the soil-rock interface almost does not affect site vibration. The constructed blasting vibration prediction model considers the site characteristics of soil-rock strata，providing a theoretical basis for blasting vibration control in such conditions.