Multi-scale investigation on the stability of soil–gravel mixture slopes using imaging analyses

Abstract

Gravel soil slopes are not only prevalent in nature but also are widely used in engineering. Understanding the damage characteristics of gravel soil slopes and preventing slope hazards requires a thorough investigation of the stability and deformation of gravel soil slopes. In this study, the stability and macroscopic deformation of slopes with varying gravel content (GC) were examined using laboratory tests and digital image correlation techniques, and the rock-winding motion on the shear zone was investigated in detail by capturing the relative motion of soil particles and gravels from a micro-scale perspective. In addition, the effects of loading location and slope angle were considered. The results indicated that there are two thresholds of 20 and 70% for the effect of GC on slope ultimate bearing capacity. Gravel soil slope shear damage was primarily caused by the gravel rotation at critical locations. There were at least five rock-inclusive movement patterns in the shear zone, and the primary cause of irregular damage on gravelly soil slopes was the difference in the relative movement of soil particles and gravels. High GC slopes were less sensitive to changes in loading location and slope angle than slopes with low GC.