Application of Mohr-Coulomb yielding criterion

摘要

The soils exhibit nonlinear behaviour under different loading conditions. Various proposals have been made to describe the strength characteristics of soil materials and many failure criteria are presently available. Owing to its extreme simplicity and good accuracy the Mohr-Coulomb's criterion combined with the principle of tension cutoff is the most widely used for soils in practical applications. This failure criterion has two main shortcomings. First, it assumes that intermediate principal stress has no influence on failure which is contrary to the experimental evidence, second the meridians and the failure envelope in Mohr's diagrams are straight lines which implies that the strength parameter Φ does not change with confining pressure. In addition, Mohr-Coulomb's failure surface as irregular hexagonal pyramid has corners (singularities) which are known to be difficult to handle in the numerical analysis.