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...

Carbonate sand is characterized by the presence of fragile grains, which may influence their mechanical response due to imposed loading; especially cyclic loading. The shear wave velocity (VS) provides relevant information for design foundation inserted in this type soil, can be obtained from laboratory tests with use bender elements (BE). This paper aims evaluate VS value a carbonate triaxial ...

Wellbore stability analysis based on a new true-triaxial failure criterion i Abstract A main aspect of wellbore stability analysis is the selection of an appropriate rock failure criterion. The most commonly used criterion for brittle failure of rocks is the Mohr-Coulomb criterion. This criterion involves only the maximum and minimum principal stresses, σ 1 and σ 3 , and therefore assumes that ...

The dynamic properties of coarse granular soils have been much less studied than in sands. From a database 14 gravel samples subjected to cyclic triaxial tests, available relationships are and new proposed estimate the normalised shear modulus G/Gmax damping ratio D as function strain γ. effect confining stress, fines content, uniformity coefficient loading frequency on variation G/ Gmax versu...

called maximum shear modulus, Gmax. It can be determined by in-situ methods from the measurements of the shear wave velocity, Vs, by means of crosshole, down-hole, up-hole, or surface wave testing. The relationship between maximum shear modulus and shear wave velocity is rigorous: 2 max s G V    where ρ is soil density. This parameter can be also obtained in laboratory by resonant column or ...