Abstract Borehole breakout initiation, progression, and stabilization are modeled using a semi-analytical method based on Melentiev’s graphical conformal mapping procedure, Kolosov–Muskhelishvili complex stress potentials. The only input data required the elastic moduli of rock, Coulomb strength parameters (cohesion angle internal friction), far-field stresses. stresses around borehole wall com...

Abstract Wellbore instability problems cause nonproductive time, especially during drilling operations in the shale formations. These include stuck pipe, caving, lost circulation, and tight hole, requiring more time to treat therefore additional costs. The extensive hole collapse problem is considered one of main challenges experienced when Zubair formation. In turn, it caused by increasing wel...

A rock failure criterion is very important for prediction of the ultimate strength in rock mechanics and geotechnics; it is determined for rock mechanics studies in mining, civil, and oil wellborn drilling operations. Also shales are among the most difficult to treat formations. Therefore, in this research work, using the artificial neural network (ANN), a model was built to predict the ultimat...

With the construction of supertall buildings such as high earth dams, linear envelope Mohr-Coulomb (M-C) failure criterion fitted to lower confined pressure would significantly underestimate loading capacity foundations, causing a huge increase in amount earthwork. Given that M-C has dominated stability analysis geotechnical structures, it is proposed this study remain invariant form but cohesi...

In order to strengthen disaster prevention control under deep resource development and space utilization, it is necessary construct a damage intrinsic model complex stress states predict the mechanical behavior of deep-rock mass cyclic loading. An indoor uniaxial loading test on sandstone was carried out in this paper. By analyzing properties energy transformation failure process, assumed that ...

We find that the classical failure criteria, i.e., maximum normal stress criterion, Tresca criterion, Mohr-Coulomb criterion, and von Mises criterion, cannot satisfactorily explain the tensile fracture behavior of the bulk metallic glass (BMG) materials. For a better description, we propose an ellipse criterion as a new failure criterion to unify the four classical criteria above and apply it t...

To clarify the factors affecting stability of deep-buried hydraulic tunnels containing pore water, elastoplastic theory and Mogi-Coulomb strength criterion were used to derive analytical solutions stress on surrounding rock-lining structure, tunnel wall displacement, plastic zone radius in rock under different operating conditions. During this process, seepage effect interaction considered. The...