More and more often, on an increasingly large scale, the geological resistance index (GSI) system is used for design practice of mining process. The GSI, a unique classifying mass rocks, linked to parameters rock strength distortion, based generalized criteria Hoek-Brown MohrCoulomb. GSI can be estimated using standard in situ tables by direct surface observations underground or mining. value p...

Breakout is a shear failure due to compression that forms around the borehole stress concentration. In this paper, breakout theory model investigated by combining equilibrium elasticity equations of with two Hoek-Brown and Fairhurst generalized fracture criteria, both which are based on Griffith criterion. This provides an explicit equation for width, but depth obtained solving quartic equation...

Abstract Footings are constructed closely to each other in mountainous rock areas and the determination of spaced bearing capacity footings on masses has become an important topic recent research. The primary aim this paper is determine efficiency factor, just like design a pile group, that can be used evaluate Hoek–Brown mass. advanced finite element limit analysis upper lower bound theorems s...

Highlights A state of art approach to evaluate the stability Hoek–Brown rock mass with a spherical cavity. Rigorous upper bound and lower solutions factors are solved using advanced finite element limit analysis. Comprehensive design charts, tables equations presented for evaluation.

There are various parameters that affect stability and expansion of failure zones in under pressure tunnels. Among the important parameters that affect failure zones around the tunnels are cohesion and internal friction angle of the rock mass. In addition, the cross sectional shape is the considerable point in failure distribution around the tunnels. The stress analysis method is one of the app...

A new failure criterion was presented to predict the ultimate strength of shale under the triaxial and polyaxial state of stress. A database containing 93 datasets was obtained from the results of the uniaxial, triaxial, polyaxial compressive tests, an indirect tensile test was collected from reliable references, and this test was carried out on the shale samples taken from the southwestern oil...

Highlights •A state of art approach to evaluate the elliptical tunnel stability Hoek–Brown rock mass.•Rigorous upper bound and lower solutions are derived using advanced finite element limit analysis.•Comprehensive design tables equations proposed for evaluation.