Soil is considered as a three-phase medium consisting of solid particles, water and air. Its behavior is very difficult to predict, especially under high rate blast loading. In this study, a new three-phase soil model for shock loading is employed to facilitate a full simulation of explosion and the subsequent stress wave propagation in soils. Upon validating the model, extended numerical calculations are carried out and the results are analyzed to demonstrate the change of characteristic parameters of the soils, the inherent distribution of the pressure on individual phases and hence the deformation mechanisms of the soils under blasting loading. Two primary deformation mechanisms exist, one is the deformation of the soil skeleton formed by the solid particles; the other is the deformation of all individual soil phases. It is found that the response of soil near the charge is dominated by the second mechanism while the first mechanism dominates in areas beyond a certain scaled range. The location of the transition zone depends primarily on the initial state of the soil. The results are useful for establishing rational and practical soil models for engineering applications concerning blasting. (C) 2003 Elsevier Ltd. All rights reserved.
