Creep and the time dependence of the strength in rocks

摘要: 1. Experiments reveal not only a quantitative difference but also qualitative discrepancy between the model of continuous medium on which mechanics deformed bodies is based and properties real solid. Thus for salt rocks it found that volume increases owing to gradual opening-up development defects microcracks. The effect compaction, in Cambrian clay, influenced by drying-out material during an experiment, closing pores gaps, recrystallization processes occur longterm tests. time factor involves serious changes our ideas behavior solid under load. Bulk deformations may exert influence formation state stress rock; particular, abutment pressure zone, expansion create additional force tends eject rock into worked-out area this especially important problem shock bumps bursts. A decrease reduces repulsive directed towards area. 2. As result laboratory tests creep long-term strength specimens potash rate\(\dot \varepsilon _1\) related, within investigated range conditions, as follows: $$\dot _1 = \dot _0 e^{\alpha \sigma }$$ (1) . The relation endurance t is $$t t_0 e^{ - \alpha }$$ (2) . 3. Experiments coefficient \ga Eq. (1) nearly equal (2). 4. Since absolute values Eqs. (2) are equal, suggested acting stresses times fracture pillars should be determined from known rates.