Different levels of stress non-uniformity usually occur in test specimens of different dimensions and aspect ratios. The effect of the choice of dimensions on the level of stress nonuniformity for hollow cylindrical specimens was studied using a linear elastic analysis during the development of a new hollow cylinder apparatus. Earlier researchers have assumed slightly different variations in th...

BIFURCATIONS, including shear band and diffuse geometric modes, arc analysed for plane strain deformation of a rectangular slab subject to a constant lateral confining stress. The response of the slab material is characterized by an incrementally linear constitutive relation that allows for the possibility of volume change accompanying shear deformation, pressure dependence and deviations from ...

Original scientific paper Failure tests were conducted on marble under different unloading confining pressure rates to obtain the energy change curve of whole-process deformation and failure. With increasing unloading rate, the peak stress differences in marble failure were reduced, confining pressure differences in failure increased, the increment ratios of each stress confining pressure were ...

We report laboratory experiments to investigate the role of gas desorption, stress level and loading rate on the mechanical behavior of methane infiltrated coal. Two suites of experiments are carried out. The first suite of experiments is conducted on coal (Lower Kittanning seam, West Virginia) at a confining stress of 2 MPa and methane pore pressures in the fracture of 1 MPa to examine the rol...

[1] The mechanical behavior of hydrate-bearing sediments subjected to large strains has relevance for the stability of the seafloor and submarine slopes, drilling and coring operations, and the analysis of certain small-strain properties of these sediments (for example, seismic velocities). This study reports on the results of comprehensive axial compression triaxial tests conducted at up to 1 ...

the mechanical behaviour of rockfill materials and aggregates depends not only on particle size and compaction, but also on their strength and lithological properties. in this research two types of large triaxial and direct shear tests are performed on rockfill materials. this paper compares the stress-strain behaviour of sandstone and andesibasalt materials in triaxial compression tests (3006...

The applicability of Artificial Neural Networks for predicting the stress-strain response of jointed rocks at varied confining pressures, strength properties and joint properties (frequency, orientation and strength of joints) has been studied in the present paper. The database is formed from the triaxial compression tests on different jointed rocks with different confining pressures and differ...

this paper studies thoroughly and deeply the results of about one hundred triaxial compression tests on thirty types of rockfill materials. the materials are categorized in accordance with their particles shape (angular / rounded) and gradation characteristics. the main tool of the study is the hyperbolic model developed by duncan and chang. the focus of the study is on the variations of deform...