Abstract: | The problem of spherical wave propagation in soil under the action of an intense uniformly decreasing load 0(t) applied to the boundary of a cavity with radius r0 is considered. Soil with a high stress level is modeled either by ideally nonlinearly compressible or elastoplastic material, taking account of linear irreversible unloading for the material. In contrast to 1–7], in order to describe material movement use is made of strain theory 8] with determining functions = (), i=i(i), where , i, , i are the first and second invariants of strain and stress tensors. During material loading these functions are presented in the form of polynomials ()=(i+2¦¦), ii)=(i-2i)i, in which constant coefficients i, i=1, 2) are determined by experiment, taking account of the triaxial stressed state of soil. Solution of the problem is constructed by an analytically reversible method, with prescribed shape for the shock-wave (SW) surface in the form of a second-degree polynomial relating to time t and a numerical method of characteristics for a prescribed arbitrarily decreasing load i(t). On the basis of the analytical equations obtained, calculations are carried out for material parameters (including loading profile) in a computer and stresses and mass velocity of plastic and elastoplastic materials are compared.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 95–100, July–August, 1986.The authors express their sincere thanks to Kh. A. Rakhmatulin for discussing the results of this work. |