On the failure mechanisms of slope due to undercutting and reinforcement effects of slope stabilizing piles

Abstract

Slope failures occasionally happened due to unstable masses during excavation of the toe of undercut slopes or weakening basal support after backfilling process can cause delay in open-pit mining. As one of countermeasures against slope failure in mining stage, a temporary slope reinforcement with stabilizing piles which is delaying a slope failure are undertaken at Mae Moh lignite mine in Thailand. In order to improve the efficiency and safety in mining, alignment of stabilized piles for mitigating undercut slope failure remains a challenging to study. In this study, reinforcement effects and failure mechanisms were investigated using a series of physical model of undercut slope with different alignments of shear pins by image analysis. It was found that the basic characteristics of shear pins have effects on a critical width of undercut slope and triggering mechanisms of slope instability.