Proposing A New Yield Criteron Of Geotechnical Mechanics And Its Application

In geotechnical mechanics and its similar fields, multifarious yield criteria are used. Mohr-Coulomb criterion is used widely in geotechnical engineering for its effective describing the characteristics of geotechnical materials. Slope stability, earth pressure and groundwork bearing capability—these three classical problems in soil mechanics have used Mohr-Coulomb criterion directly or indirectly. For the difficulty of Mohr-Coulomb criterion in finite element calculation, many finite element programs use Drucker-Prager criterion by supposing geotechnical materials are elasto-plastic, but the effect isn't good. Thus a new criterion that can describe the characteristics of geotechnical materials and be used in finite element method conveniently is urgently needed. Therefore, the research of this paper has very important academic and practical engineering guide significance.Based on the established plastic theory and Mohr-Coulomb criterion, a new D-P type criterion is proposed. The criterion can be used in finite element method conveniently for its slick yield surface. In addition, the criterion embodies the influence of medial stress to yielding, which makes up the limitation of Mohr-Coulomb criterion.With the development of personal computer and the improvement of finite element calculation technique, the strength reduction of finite element method is becoming the new trend in analyzing the slope stability problems. Connecting the strength reduction of finite element method, the paper used the new criterion to analyze slope stability problems by importing it into ANSYS program. The research showed that the results obtained by the new criterion were fairly close to those obtained by traditional methods. The reliability of the new criterion is proved. Thus, the application of the new criterionis recommended. Other applications of the new criterion in geotechnicai engineering need farther research and validation.