Creep Behavior of Cankiri-turkey Rock Salt Under Uniaxial and Triaxial Loading Conditions

The Cankiri rock salt region formed during the Tertiary period is an important mine region of Turkey. In the region, an underground room-and-pillar mining are used to extract rock salt. However, the database of mechanical properties was insufficient for design studies. Therefore, rock mechanics experiments were performed on core and cubic specimens. It was understood from preliminary studies that the scale effect on the uniaxial compressive strength (UCS) does not exist when the diameter (D) and width (W) for both specimen types are D >= 50 mm and W >= 50 mm. Some experiments were designed to determine creep behavior. The creep behavior under uniaxial and triaxial loading was investigated using the uniaxial (UCT) and triaxial creep tests (TCT). Finally, a mathematical model describing the creep behavior was developed by statistical software SPSS V10. The model parameters were time, uniaxial and confining pressure. Values calculated using the proposed function were compared with experimental results.