关键词: 岩土工程；道路工程；硅砂；分离式霍普金森杆；破碎特征；能量耗散；动力响应

Abstract: To deepen understanding of the mechanical properties of silica sand particles under impact loading, and enhance the theoretical foundation for the application of silica sand in energy dissipation in protective engineering, an improved split Hopkinson pressure bar (SHPB) apparatus was used to investigate the propagation law of stress waves, particle breakage behavior, and energy absorption effect of silica sand under medium and high strain rates. Results indicate that the velocity of stress waves in silica sand is directly proportional to the particle size, while the peak stress propagation speed exhibits a linear negative correlation with particle size. Additionally, the attenuation capacity of silica sand to stress waves increases with the increase of particle size, showing a linear relationship. Large-sized particles are more prone to fracture under impact, which can effectively increase the degree of energy dissipation. The particles after crushing exhibit a clear fractal distribution pattern, and the fractal dimension shows a good linear correlation with the crushing rate. According to the energy absorption efficiency characteristics of silica sand, under the same stress level, larger particles show higher energy absorption efficiency; under the same strain level, smaller particles demonstrate stronger energy absorption efficiency due to their lower compressibility. In practical engineering, larger particles are recommended to improve energy absorption efficiency, while smaller sizes are preferable when controlling deformation or enhancing stability is required.

Key words: geotechnical engineering; highway engineering; silica sand; split Hopkinson pressure bar (SHPB); crushing characteristics; energy dissipation; dynamic response