Evaluating Time-to-Failure in Rocks by Long-Term Strength Criterion
A. M. Kovrizhnykh, V. D. Baryshnikov, A. P. Khmelinin
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Rock mass creep, long-term strength, limit shear deformation, dilatancy, time-to-failure
Abstract
The mathematical modeling of creep and long-term strength of rocks uses the non-associated flow rule. The authors propose a unified approach to the plasticity and creep processes. The theoretical calculations are compared with the testing data of different materials. In creep deformation in rocks, the applied problems on limit state of rock mass in plain strain are considered: pressure applied by a solid die block with flat bottom on rock mass limited by a horizontal plane and occupying the bottom part of a half-space; instability of pit wall or natural slope under different loads. These problems evaluate stresses in the limit state zones and the times-to-failure in rocks mass with regard to internal friction.
|
