Influence of Swelling on Shear Strength of Shale-Limestone Interface

Abstract

Rock slope stability is almost controlled by the behaviour of the interface between rock layers. The presence of shale layers between limestone layers complicates this behaviour. As the shale layer undergoes swelling with moisture, it causes the shear interface properties to change with a specific behaviour different from the dry state. The behaviour will depend on the shale’s degree of saturation, swelling percentage, and stress level over shale. An experimental program was carried out to determine the shear interface behaviour parameters of shale-limestone during swelling phenomena to guide stability checks. The interface cohesion and friction angle results are reported along the swelling process and compared with the dry state condition. These results help engineers assign adequate and accurate values for joint shear and normal stiffness in jointed rock slopes, including swelling layers.

Estimation of Shear Strength Parameters Considering Joint Roughness: A Stability Case Analysis of Bedding Rock Slopes in an Open-Pit Mine

“…In this paper, generalized shear strength parameters considering roughness are established for sandstone anastomosing non-filled joints, but rock joints under engineering conditions are often non-anastomosing [41] and filled [42], and how to establish generalized shear strength parameters for joints with different conditions using the method in this paper needs further research.…”