Mehdi Amini

In-Flight Excavation of Slopes with Potential Failure Planes

AbstractThe stability of an in-flight undercut slope with a potential failure plane was investigated under a centrifugal acceleration of 50g. The experimental results confirmed the formation of passive arch action in the undercut slope and were found to be in good agreement with the results of 1g physical model tests showing that the arching-type failure in undercut slopes is a scale-independent phenomenon. The maximum stable undercut span is compared with that in the theory developed by the authors, and the results are discussed.

Active earth pressures for non-planar to planar slip surfaces considering soil arching

ABSTRACT The soil arching behind a rigid retaining wall was considered using log-spiral and parabolic slip surfaces with a changeable curvature defined by a new parameter Rpl so called “planar ratio of slip surface”. By increasing Rpl , the difference between log-spiral and parabolic slip surfaces reduced. When Rpl approached one, both slip surfaces reduced to a planar slip surface. Moreover, equations for the estimation of earth pressure in the failure zone behind the wall were developed. It was observed that as the wall height decreased, the curvature of the slip surfaces behind the wall decreased leading to a larger value of Rpl . Therefore, the assumption of a planar slip surface behind retaining walls can be realistic only for shallow walls. As the wall height increases, the slip surface appeared to be more non-planar. The results of the developed formulations showed a good agreement with the experimental data.

A new rating system approach for risk analysis of rock slopes

In this paper, an approach is presented to analyze the stability risk of rock slopes based on a new rating system. Three factors are used to estimate the risk level of rock slopes: (1) failure probability, (2) element at risk rating, and (3) vulnerability rating. Element at risk and vulnerability ratings are both given a range from 0 to 10, and the probability of failure is varied between 0 and 1, so the risk rating ranges between 0 and 100. This risk rating can be used to determine both the quantitative and qualitative risk levels of slopes at the same time. The method is tested on the western sector of the slopes facing Songun copper plant phase III, Iran, to clarify its procedures and assess its validity. Deterministic kinematic analyses showed that the slope has a potential for circular failure. Risk assessments revealed that the risk levels of the slope in both static and pseudo-static conditions are “very low” and “high,” respectively.