An analysis of elastoplastic soil deformation due to short-term loads

The paper deals with certain practical problems encountered in designing the bases and foundations of industrial structures. These problems are concerned with the calculation of residual deformation in soils subject at their surface to short-term loads or to a vertical shock load from a falling body that can be treated, with respect to the soil, like a rigid testing plate. Used to determine the strained state of the nonrock, unsaturated soils is the method of solving one-dimensional problems of the dynamical theory of elasticity, the soil being represented by an elastoplastic model with strengthening and load relief. The effect of an air-shock wave or the impact of a heavy, rigid testing plate on the soil surface has been investigated to obtain data for the design of industrial structures that have explosion hazardous rooms or processing equipment using explosive energy in its operation (for example, the production of large metal parts by the explosive forming process), for assessing the degree to which soils are compacted by explosions at the soil surface, and for other similar purposes. An approximate solution of the equations for the propagation of elastic and plastic waves in the soil was obtained by the method of characteristics, taking into account the load-relief waves. The solution is given in the closed form for various versions of elastoplastic models for a homogeneous soil massif or for a layer of finite thickness. The final aims of the calculations are to determine the residual settlement of the soil surface, the stress and strain distribution along the depth of the soil, and the lower boundary of plastic deformation.