Axially-symmetric plastic deformation in soils—II. Indentation of ponderable soils

Summary Cox, Eason and Hopkins 1 have developed a general theory of axially-symmetric plastic deformations in ideal soils. This theory was applied, in particular, to discuss incipient plastic flow in a semi-infinite mass of imponderable soil loaded by a smooth, rigid, flat-ended, circular cylinder (or punch). This situation is here discussed further with duo account of the weight of the soil. Values of the mean yield-point pressure for indentation by a punch have been obtained, using the R.A.R.D.E. digital computer AMOS, for a range of values of a dimensionless soil weight parameter, G , and the angle of internal friction of the soil, Φ. In addition, in view of its close similarity to the axially-symmetric problem, results are also presented for the corresponding plane strain problem of indentation by a smooth, rigid, flat-ended die. The results show clearly, in both cases, the strong dependence of the mean yield-point pressure upon soil weight for frictional soils.