Guidelines for Open Pit Slope Design

Abstract

Guidelines for Open Pit Slope Design is a comprehensive account of the open pit slope design process. Created as an outcome of the Large Open Pit (LOP) project, an international research and technology transfer project on rock slope stability in open pit mines, this book provides an up-to-date compendium of knowledge of the slope design processes that should be followed and the tools that are available to aid slope design practitioners.
 This book links innovative mining geomechanics research into the strength of closely jointed rock masses with the most recent advances in numerical modelling, creating more effective ways for predicting rock slope stability and reliability in open pit mines. It sets out the key elements of slope design, the required levels of effort and the acceptance criteria that are needed to satisfy best practice with respect to pit slope investigation, design, implementation and performance monitoring.
 Guidelines for Open Pit Slope Design comprises 14 chapters that directly follow the life of mine sequence from project commencement through to closure. It includes: information on gathering all of the field data that is required to create a 3D model of the geotechnical conditions at a mine site; how data is collated and used to design the walls of the open pit; how the design is implemented; up-to-date procedures for wall control and performance assessment, including limits blasting, scaling, slope support and slope monitoring; and how formal risk management procedures can be applied to each stage of the process.
 This book will assist in meeting stakeholder requirements for pit slopes that are stable, in regards to safety, ore recovery and financial return, for the required life of the mine.

Assessing the Shear Strength of Rock Discontinuities at Laboratory and Field Scales

“…Bandis et al (1981) postulated a gradual reduction in effective roughness over 5 m of undulating surfaces; the concept is extended for up to 10 m of discontinuity length (Hoek 2014;Read and Stacey 2009) based on Barton (1982) so has some authority as a guideline and needs to be addressed here. The basis for the JRC reduction with length empiricism stems largely from research by Bandis (1980), published by Bandis et al (1981).…”

Systems Engineering Approach to Slope Stability Monitoring in the Digital Mine

“…The formulation of the "geotechnical questions" to be answered with the assistance of the monitoring system (Guidelines for Open Pit Slope Design [4]) requires a structured approach. The engineering of rock mass necessarily involves an analysis of the (potentially complex) interplay between the dominant rock mass components relevant to the design, implementation and maintenance of the excavation.…”

“…Resources 2020, 9, x FOR PEER REVIEW 7 of 14 systems to monitor a single wall is rare at this and other coal mine sites, due to the prohibitive costs associated with such systems. shows the RES analysis that was conducted specifically for the East wall being monitored at the mine, considering the interactions of the four geotechnical model components (as defined in Guidelines for Open Pit Slope Design [4]) and the mine slope stability. Actual site conditions and the historical performance of mining activities (e.g., blasting) were taken into account, based on the advice from geotechnical engineers at the mine and geotechnical consultant reports.…”

“…Therefore, the characterization of all four geotechnical model components are relevant for the East wall. This RES analysis has therefore provided a justification for establishing the monitoring system requirements (as required by Guidelines for Open Pit Slope Design [4]). The following high-level monitoring requirements have been defined: R1: Adequate monitoring of the pore pressures and phreatic surface well behind the highwall R2: Geotechnical characterisation of the geological structures in the domain of interest and Based on this RES, the critical rock mass behaviours requiring characterisation and monitoring were identified.…”

“…plan regular calibration and maintenance; and h. establish trigger action response plans (TARPs) and associated accountabilities However, in [4], it is also observed that instruments are often placed without this focus and therefore both the efficiency and effectiveness of the monitoring program are compromised. Part of the reason for this problem is that there is little guidance in the literature for completing steps a to d shown above, and therefore there is great reliance on the expertise of the practitioner.…”