Guidelines to design the scope of a geotechnical risk assessment for underground mines

Abstract

Risk assessment has been seen as an important tool in reducing accidents. Use of risk assessment tools also has its significant presence in the underground mining industry in preventing work related hazards. Geotechnical uncertainty however is among the leading cause behind major accidents such as roof collapse, airblast etc., which leads to multiple fatalities and financial loss. Geotechnical risk assessment done at stages as early as mine design can help justify a different mine design aspect such as support methods for a risky area different from the rest of the mine. The aim of this paper is to organize the geotechnical risk assessment process to suit the underground mining needs. A numerical ranking system has been developed to plan the risk assessment process and choose amongst the risk assessment tools. The risk assessment process has been redefined into four sections namely — hazard identification tool, risk assessment approaches, risk assessment parameters and risk representation tool. Risk identification tools have been shortlisted to suit underground mining needs through literature review. Risk assessment approaches have been defined into deterministic, probabilistic and possibilistic approaches with relevance to geotechnical assessment. Elements to be considered in an underground mine for a geotechnical risk assessment have been structured into classes. Establishment of scope of a geotechnical risk assessment based on these classes has been explained. Selection guideline for the appropriate risk identification tool has been defined based on the scope of risk assessment. The significance of the risk assessment approach has been explained and a numerical ranking system has been formulated which can be used by an underground mine to choose among the probabilistic, possibilistic and deterministic approaches.