Re-examination of the shock wave’s peak pressure attenuation in soils

The paper investigates the problem of a charge exploding in soil and focuses on the characteristics of the shock wave’s peak pressure attenuation. Analysis of existing empirical data observes different attenuation factors for apparently similar certain types of soils whereas for other types of soils there is no significant difference. It was also observed that prediction of the shock wave’s peak pressure with existing power law empirical formulas yields a large discrepancy in comparison to test data. The discrepancy is significant even in case where the specific tested soil parameters are used. These observations among others motivated this study. The power law relationship has been investigated through numerical simulations of the shock wave propagation in different soils. The soil is modeled as a bulk irreversible compressible elastic plastic medium, including full bulk locking and dependence of the current deviatoric yield stress on the pressure. The Lagrange approach and the modified variational difference methods are used to simulate the process. The study shows that the shock wave’s peak pressure attenuation for certain types of soils may be well presented by a power law with a constant exponent, whereas other types of soils may be presented by a power law for a limited distance range and their behavior for a wide distance range is poorly described by a linear relationship on a logarithmic scale but is well represented by a bi-linear or a tri-linear realtionship. These findings explain some of the above mentioned observations.