In-situ rock mass stress-state measurements in scales of mineral deposits: problem-solving

This paper describes the new method for in-situ measurements of the most large-scale stress fields that are comparable to dimensions of deposits and mining leases. The method considers open cast mines and collapse zones of underground mining as disturbing cavities. The calculation of stresses is carried out thru measured deformations for the conditions of plane stressed state from the measured displacements of survey marks on the earth surface. GPS or GLONASS technology is used for the measuring. The results of in-situ study deformations of pit edges Pipe Udachnaya Mine (Sakha Republic, Russia) have been presented as an example of practical application of the method.

Stressed-Strain State of Multi Layer Foil under One-Axis Tension

Multilayer protective materials and coatings attract attention last years because the possibility appears to obtain unique properties of materials due to combination of properties and sizes of layers. In his paper analytical solution is constructed for the problem on multilayer foil tension. It is assumed that stress and strain tensor components depend on one space coordinate in the axis direction perpendicular to layers and generalized plane stressed state is realized. Interesting effect is detected for two-layer material: thickness of the coating exists when one of diagonal stress tensor components is minimal, that ensure minimal break in the corresponding stresses in interface. This effect is observed previously experimentally by many authors. However, other diagonal component of stress tensor has maximal value for other value of coating thickness. The positions of the maximal and minimal values of stresses and breaks depend on combination of properties and thicknesses of layers.