Mechanical behaviour of an anisotropic porous sandstone affected by different loading histories and rates

Abstract

Results of an extensive experimental study on mechanical properties of an anisotropic sandstone subjected to different loading histories and loading rates during monotonic and cyclic loading are presented. Cyclic loading test were performed in uniaxial and triaxial condition and loading rate tests were undertaken under unconfined condition. The mechanical properties of the rock were altered by cyclic loading; dependent upon the applied stress level during cyclic loading the rock may become weaker or stronger as a result of cyclic loading. The strength and the stiffness of the sandstone were increased with an increase in loading rate. In addition, it was found that increase of loading rate will increase fatigue life during cyclic loading.