Experimental Study on the Damage Characteristics and Fracture Behaviour of Rock-like Materials with Weak Interlayer Zones

To study the effect of the dip angle of the weak interlayer zone (WIZ) on the damage characteristics and fracture behaviours of rock-like samples, a series of uniaxial compression tests were conducted, accompanied by acoustic emission (AE) tests and the digital speckle correlation method (DSCM). The experimental results indicate that the stress-strain curves before the peak can be divided into plastic-elastic-plastic and elastic-plastic curves, and the stress-strain curves after the peak can be divided into plastic failure, transitional failure and brittle failure curves. The relationship between the peak stress and peak strain and WIZ angle can be well described by two linear functions. As the angle increased, the specimen gradually changes from tensile failure to shear failure, and the number of cracks and falling fragments decreases gradually. In addition, it becomes difficult to predict rock mass failure by AE when the WIZ angle is close to 60 degrees. The AE counts decrease with an increasing angle, reach a minimum at 60 degrees, and then increase. Furthermore, the WIZ plays a key role in the deformation of upper hard rock.

Automated summary

This study investigates the effect of the dip angle of the weak interlayer zone (WIZ) on the damage characteristics and fracture behaviors of rock-like samples. The results show that as the angle increases, the specimen transitions from tensile failure to shear failure, and the number of cracks and falling fragments gradually decrease. Moreover, it becomes difficult to predict rock mass failure using acoustic emission (AE) when the WIZ angle is close to 60 degrees.