Abstract:Considering the geological formation characteristics of most salt mines in China,experimental studies of uniaxial and triaxial compression were carried out on three kinds of interlayered salt rock samples. The experiments indicated that the presence of mudstone interlayer affects the deformation and failure characteristics of samples remarkably. It was observed that the mudstone fractured prior to salt rock though its uniaxial peak strength is higher than that of the later,and a stress drop phenomenon was also observed in these tests. Motivated by the experimental phenomena,an analysis of the influence of interlayer based on the Cosserat medium expanding theory was presented. The theoretical results indicate it is the mismatch of mechanical properties of two adjacent layers that result in an equivalent tension stress are applied to the stiffer interlayer. The analytical results may provide a theoretical frame for further study on the stability of the oil/gas storage cavern in bedded salt rock formation.