Limit Analysis of the Bearing Capacity of Fissured Materials

摘要

Formulations for the upper and lower bound theorems of plasticity are presented211u001efor fissured soil and jointed rock. The methods ignore elastic deformations and 211u001eare based on the assumption that the fissured soil or rock mass can be treated as 211u001ean anisotropic, rigid-plastic continuum. In the upper bound formulation, velocity 211u001ediscontinuity multipliers are introduced to deal with the discontinuities in the 211u001evelocity field. For both the upper and lower bound formulations, linearized 211u001efailure surfaces for the fissured materials are developed. The illustrative 211u001eexamples indicate that the new procedures are very efficient even when a quite 211u001ecoarse mesh is used to represent the mass of failing material, and that the 211u001e'exact' failure loads are always bracketed by the upper bound and lower bound 211u001ecalculations. Moreover, by increasing the number of planes in the failure surface 211u001eor/and refining the meshes, the accuracy of the bounds is raised.