Investigation of stress wave distribution patterns from high aspect ratio charges in soil

Stress wave distributions from soil explosions involving charges of varying aspect ratios exhibit significant directional variations. Understanding these distribution patterns is crucial for the design of underground protective structures. In this study, a borehole-based charging and sensor placement method was developed to measure normal and lateral stresses induced by explosions in soil. Propagation patterns of stress waves generated by TNT and aluminized explosives were obtained under typical geological conditions. A numerical model of underground explosions was constructed and validated against experimental data, with a maximum deviation of 10.3%, confirming the accuracy of the numerical algorithms, material models, and parameters. Numerical simulations revealed that cylindrical aluminized charges produce highly anisotropic pressure distributions, with axial–radial differences and localized high-pressure zones that vary by azimuth angle. Furthermore, the peak pressure along the 0° azimuth decreases with increasing aspect ratio, while that along the 90° azimuth increases. A predictive model for peak stress, incorporating aspect ratio, azimuth angle, and scaled distance, was developed. This model provides a basis for designing underground protective structures using both measured and predicted stress distributions.