This study is to investigate the effect of the interlayer on mechanical properties and failure mechanisms of salt rock containing interlayers. To overcome the difficulties of field sampling

salt rock samples were prepared in the laboratory for uniaxial and triaxial compression experiments. The experimental results showed that the deformation difference between salt rock and interlayer had a great effect on the mechanical properties of interlayer-bearing salt rock

such as strength and elastic modulus. Under uniaxial compression condition

the fracture failure of salt rock initiated from the interlayer

and then developed into the salt rock layer. It was found that the compressive strength decreased with increasing the interlayer thicknesses. The compressive strength of salt rock samples containing a single interlayer was higher than that of salt rock containing two interlayers. The compressive strength and elastic modulus of salt rock were weakened by the inclined angles of the interlayer. Furthermore

the types of damage in bedded salt rock can be divided into fracture and slippage along the interface between interlayer and salt rock. Under triaxial compression condition

all the compressive strength

elastic modulus and deformation at peak load of bedded salt rock were lower than those of pure salt rock. The pure salt rock demonstrated lateral expansion and failure

and no obvious rupture surface was found. While the mudstone interlayer in the sandwich salt rock showed the characteristics of shear failure

and part of the salt interlayer was lateral expansion. Therefore

this paper can provide helpful guidance to the construction and operation of gas storage caverns in bedded salt rock.