Proceedings of the First International Conference on Mining Geomechanical Risk最新文献

{"title":"Challenges with use of risk matrices for geohazard risk management for resource development projects","authors":"M. Porter, M. Lato, P. Quinn, J. Whittall","doi":"10.36487/ACG_REP/1905_01_PORTER","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_01_PORTER","url":null,"abstract":"Geohazards comprise a subgroup of natural hazards associated with geotechnical, hydrotechnical, tectonic, snow and ice, and geochemical processes that can pose a threat to worker and public safety, asset integrity, and asset management lifecycle cost. Like for most types of threats, the risks from geohazards can be assessed qualitatively or quantitatively and used to inform a geohazard management program. \u0000Most mining companies use risk matrices to aid in the assessment, prioritisation, communication and management of corporate risks. These matrices use standardised descriptions of likelihood and consequence to help users assess risks of negative outcomes to health, safety, the environment, assets, and reputation, and are tailored to each organisation’s types of risk exposure and level of risk tolerance. \u0000Geohazards and related geotechnical failures can represent low-probability, high-consequence events that plot in the highest risk zones of most corporate risk matrices. Variability in spatial and temporal probabilities for people and infrastructure exposed to geohazards can have a large influence on risk exposure, and this can be challenging to assess and communicate effectively with some risk matrices. Risk is scale-dependent: the business risk due to rockfall from a single slope along a mine access road is vastly different than the total risk due to rockfalls from all slopes along that road, yet guidance is often missing on how the risks from these scenarios should be plotted on a risk matrix. These and other pitfalls associated with use of corporate risk matrices for informed geohazard management are explored.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124300828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geotechnical risk analysis for the closure alternatives of the Chuquicamata open pit","authors":"L. Contreras, E. Hormazabal, R. Ledezma, M. Arellano","doi":"10.36487/ACG_REP/1905_22_HORMAZABAL","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_22_HORMAZABAL","url":null,"abstract":"The development of the geotechnical risk model for the Chuquicamata mine started in 2005 and included the safety and economic impacts of slope failures at different scales (Tapia et al. 2007; Steffen et al. 2008). The model has been updated recently to include a quantitative evaluation of large economic impacts derived from inter-ramp and overall slope failures using a probabilistic approach (Contreras 2015). This paper describes how the later component of the model was used as a tool for the evaluation of four closure alternatives for the open pit. The methodology included three main tasks: \u00002. Evaluation of the consequences of slope failure associated with economic losses derived from impacts on production and costs. \u00003. Generation of risk maps to compare several closure alternatives. \u0000The results of these analyses provided information on magnitude of impacts and their likelihood for the four closure alternatives evaluated. The evaluation of these results facilitated the selection of the appropriate closure alternative considering the mine reference criteria for economic risk.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131736265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying uncertainty in mining geomechanics design","authors":"M. Dunn","doi":"10.36487/ACG_REP/1905_23_DUNN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_23_DUNN","url":null,"abstract":"Uncertainty in mining geomechanics and geotechnical engineering is a broad term that accounts for natural variability, lack of data, and lack of knowledge. Reducing uncertainty is a key component of the mining study process and in managing geomechanical/geotechnical risk. Understanding and reducing uncertainty is also a key activity in the design process to ensure that designs are robust and resilient. \u0000A variety of methods are used in geomechanical design including empirical, analytical and numerical modelling. All design methods require inputs, and these are based on data from core logging, mapping, laboratory testing, field observations, and monitoring. This data then must be compiled and interpreted so that meaningful and reliable design inputs with a reliability that is commensurate with the level of design (scoping through to operational) can be derived. This includes the development of the geomechanical or geotechnical model. The uncertainty of the geotechnical model is often described in terms of confidence or reliability. \u0000Currently, very little quantitative guidance exists in the literature on assessing the confidence level of geotechnical studies and design, although there have been attempts by various authors (Haile 2004; Haines et al. 2006; Read 2009; Dunn et al. 2011) to qualitatively describe what level of geotechnical data is required. Several authors have outlined methods that could be applied to assess the reliability of geotechnical data (Read 2013; Fillion & Hadjigeorgiou 2013; Dunn 2015). \u0000Data from a range of projects are reviewed and summarised and an attempt made to quantify the uncertainty for some data, and illustrate the impact this can have on designs and commonly used design acceptance criteria.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116681091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What are the real risks for tailings facilities?","authors":"B. Brown","doi":"10.36487/ACG_REP/1905_0.2_BROWN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_0.2_BROWN","url":null,"abstract":"The movement towards risk-based design and operation of tailings storage facilities (TSFs) has taken place over the last few decades. The establishment of the consequence of failure of a facility is used to determine the design criteria to be used in its design. These criteria generally set the acceptable return periods for seismic and hydrologic events that the facility must accommodate. In addition, there are generally several levels of risk assessment of the design carried out to highlight technical risks that require particular attention and controls to manage. These are usually addressed in the design phase of project development. \u0000Despite this focus on technical risk assessment at the design phases of the development of a TSF, there is still a significant number of failures occurring every year. In recent times, there have been a number of high profile TSF failures in facilities owned by major mining houses and/or located in highly regulated, first world countries. In almost every case, the investigations into the failures have been carried out by high profile, internationally recognised geotechnical engineers who have identified the technical reasons for the failure. \u0000In many cases, it has been shown that the root causes of the failures have been a failure in governance, capital constraints, change management, independent reviews, construction supervision, operation, etc. The investigation of failures and reports to the public are almost exclusively focused on the technical cause with much less focus on what is often the underlying root cause. \u0000A number of international mining industry groups have recognised the lack of effective governance as being a major risk that could lead to TSF failures. The Mining Association of Canada (MAC) and the International Council on Mining and Metals (ICMM) are two examples. \u0000In this paper, the various methods for risk assessment and management are described. Non-technical risks that arise in the design and operation of TSFs are discussed and importance of good governance and continuity of its application during the full lifecycle of the facilities is emphasised.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128081331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk-based access control at Mount Isa Copper Operations","authors":"G. Potgieter, A. Grubb","doi":"10.36487/ACG_REP/1905_0.4_POTGIETER","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_0.4_POTGIETER","url":null,"abstract":"Mount Isa Copper Operations (MICO) is one of the oldest and deepest mines in Australia, comprising the largest underground network of mine development in the world. During the early operational years, ground support, particularly surface support, was not routinely installed. Although rehabilitation in recent years has drastically reduced the amount of tunnel without support, there remain tens of kilometres of excavation with limited to no ground support installed. In addition, older development was often mined within close proximity to unfilled or partially filled stopes and vertical openings. The voids pre-date modern 3D mine plans and scanning technology. Furthermore, access to the voids to conduct scans is limited, this results in an imperfect understanding of the void sizes and proximity to accessible drives. The lack of ground support and knowledge of void status poses significant ground failure risks at MICO. \u0000A significant increase in rock related near-hit incidents occurred during the second half of 2014 and the first half of 2015. A number of these incidents had the potential to cause severe or fatal harm. The incidents triggered internal investigations that aimed at understanding and reducing the ground failure risk. The outcome of the investigations was the creation of a series of interlinked systems, namely the tunnel condition risk assessment (TCRA), mine closure areas (MCA), ground awareness training (GAT), vertical opening pillar hazard assessment and control (VOPHAC), stope void review (SVR), manual scaling crews, fall of ground database and the quality assurance/quality control management plan (QA/QC MP). The individual components of the system are specialised and simple. However, the system is comprehensive and robust. Each of the components, as well as how they interlink, is discussed within this paper. \u0000The interlinked systems and practices provide controls and have proven to be effective at reducing the ground failure risks. Although the systems were developed at MICO, they have the potential to be easily adapted and utilised at other mine sites.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124267061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using qualitative risk assessment as a leading indicator for geotechnical risk in mining","authors":"E. Hamman, J. Venter","doi":"10.36487/ACG_REP/1905_05_HAMMAN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_05_HAMMAN","url":null,"abstract":"Investor confidence is largely driven by a mining company’s ability to deliver on the guaranteed return on investment. Thus, robust due diligence processes, functioning as part of a mining company’s corporate governance, become essential tools to identify hazards that can impact production, assess the associated risks and introduce controls to manage the risks. \u0000The geotechnical practitioner is tasked to manage one of the biggest risks on the mine; that of a rock mass instability. Since an instability, or collapse, need not be large to have a significant impact on production, the challenge is to develop an optimised life-of-mine design with a risk management plan that suits the risk requirements of the mining company and investors, whilst meeting acceptable, minimum safety standards. \u0000The concept of a Geotechnical Review Board has been adopted in the industry as a vehicle to provide assurance that the geotechnical risks on a mine have been identified and are being properly managed. The review relies on external parties providing appraisals of the design and processes, and experienced oversight of the active operations. In general, these reviews tend to have a unique style; often a combination of the current, visible, critical issues on the mine and issues deemed as important by either the reviewer or a third party. Coupled with the challenge of fluidity in modern planning environments, the geotechnical practitioner is often still faced with uncertainty in the level of geotechnical risk associated with any given mine plan. \u0000This paper introduces a geotechnical risk assessment tool that has been developed for use as a leading indicator within AngloGold Ashanti’s international operations. The authors aim to provide the reader with insight into how the tool can be utilised to understand a mine’s ability to proactively identify and manage geotechnical hazards, by exploring the following components:","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116079508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-driven geotechnical hazard assessment: practice and pitfalls","authors":"W. Mcgaughey","doi":"10.36487/ACG_REP/1905_11_MCGAUGHEY","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_11_MCGAUGHEY","url":null,"abstract":"Geomechanical risk in mining is universally understood to depend on many apparently disparate factors acting together such as stress, stiffness, mine geometry, rock mass character, rock type, structure, excavation rate and volume, blasting, and seismicity. We have worked on many case studies over the years in both underground and open pit mines with the objective of discovering and documenting the correlation of such factors with the experience of geomechanical failure. Whether that failure is slope failure, strainbursting, fault slip-induced rockbursting, roof fall, or any other of many possible failure types, statistical correlations among the different classes of data can be found, and predictive rules for understanding geohazard based on their quantitative combination can be established and deployed in day-to-day operations. This data-driven approach requires application of methods and avoidance of pitfalls that can be standardised into a universally applicable workflow. We discuss the workflow and the pitfalls in analysis to be avoided through case study examples.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122919375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calibration of a seismic hazard assessment tool using velocity fields and geotechnical data","authors":"Y. Abolfazlzadeh, L. Smith-Boughner, Zara Anderson, A. Jalbout, Alexander Mataseje","doi":"10.36487/ACG_REP/1905_12_ABOLFAZLZADEH","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_12_ABOLFAZLZADEH","url":null,"abstract":"The majority of seismic hazard assessment tools are solely based on statistical analyses of several seismic source parameters such as event rate and time, and seismic moment. These analyses are often applied to the entire mining area which can impact the accuracy and reliability of the hazard assessment tool in each zone. Experience has shown that mining geomechanical risk is complex and its mitigation needs a broad understanding of other geotechnical factors such as rock mass properties, geological structures, mining method, stress regime, etc. Since all the contributing parameters and their impact are not entirely understood, it is critical to apply a range of geotechnical/geomechanical analyses in correlation to each other and quantify the changes in the rock mass behaviour. The goal of this paper is to develop a seismic hazard assessment tool calibrated for each geotechnical domain within the mine. To develop the tool, we incorporated mine geotechnical and geological data, seismic source parameters, and tomography analyses from a hard rock underground mine in North America. There exist several sub-vertical faults and one horizontal structure in the mine which create clear contrasts in rock mass behaviour across the structure. The results show good correlation among the different datasets, and a calibrated seismic hazard tool has been developed that provides ongoing updates to the mine operation.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127199684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geotechnical design and uncertainty in residual soil slopes","authors":"K. Mandisodza, M. Dunn","doi":"10.36487/ACG_REP/1905_29_MANDISODZA","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_29_MANDISODZA","url":null,"abstract":"Mining in residual soils is a characteristic of some open pit mines, particularly those mines in the tropical and sub-tropical regions. With residual soils’ prevalence on the earth’s surface almost as common as that of sedimentary rocks (Wesley 2013), mining in such soils requires special understanding of the behaviour and characteristics of the residual soil to determine slope designs that are both safe and economic. Due to the presence of relict structures, and the relatively low strength of the residual soils and weathered rock, design slope angles in these materials should be developed by blending the results of the kinematic assessments of geologic structures with rock mass stability analyses and traditional soil mechanics (Newcomen & Burton 2000). It is thus imperative that geotechnical designs should be site/location-specific and based on soil’s field performance, back-analyses and risk zoning. Understanding the variability of these materials is important for developing robust designs. This paper outlines the different aspects that are to be considered when conducting slope designs in residual soils, and in particular, saprolites, and summarises shear strength data from various mine sites that highlights the uncertainty associated with these parameters.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133943245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic exclusions and re-entry from a risk perspective","authors":"Tierney, K. Woodward, Johan Wesseloo","doi":"10.36487/ACG_REP/1905_08_TIERNEY","DOIUrl":"https://doi.org/10.36487/ACG_REP/1905_08_TIERNEY","url":null,"abstract":"Exposure to seismic hazard in mines is controlled through various evacuation, exclusion and re-entry procedures. The aim of exposure management procedures is to tactically reduce the safety risk by removing personnel from work areas during periods of elevated seismic hazard. Given that risk assessment is based on exposure, the design of exposure management procedures must also be risk-based. \u0000In practice, the decision to re-enter a workplace after an exclusion is generally only made based on an assessment of the seismic hazard, often using previously defined levels of tolerable seismic activity rates. The definition of tolerable seismic hazard, in the context of re-entry, is seldom quantitatively assessed based on risk. In order to move towards a comprehensive seismic risk management strategy, design methodologies must be able to quantify the impact of different exclusion and re-entry practices on risk. The appropriate reentry practice can then be selected given the defined risk-based design acceptance criteria. \u0000There is still a long way to go before the risk-based design framework for exposure management procedures is complete. This paper reviews the current state of design of exposure management controls in the context of risk and discusses several important areas for further research.","PeriodicalId":337751,"journal":{"name":"Proceedings of the First International Conference on Mining Geomechanical Risk","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129843669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}