Academia.eduAcademia.edu

Figure 3 – uploaded by Marwan Alheib

See full PDFdownloadDownload figure
Fig. 3 Event tree developed for a slope stability hazard (open-pit lake) and potential risk and mitigation and intervention measurements, modi- fied from (Chin and Chao 2009)

Figure 3 Event tree developed for a slope stability hazard (open-pit lake) and potential risk and mitigation and intervention measurements, modi- fied from (Chin and Chao 2009)

Related Figures (18)

Fig. 1 Example of transforming of an open pit mine into a touristic lake and leisure activities (e.g., Albi lake, France, credit Charbonnages de France)
Fig. 1 Example of transforming of an open pit mine into a touristic lake and leisure activities (e.g., Albi lake, France, credit Charbonnages de France)
Fig. 2. Flowchart of the risk analysis of open-pit mine lakes
Fig. 2. Flowchart of the risk analysis of open-pit mine lakes
Table 3 Summary of natural hazards (20) and their potential interaction in the presence of a mine lake (post-mining or reclamation situation)
Table 3 Summary of natural hazards (20) and their potential interaction in the presence of a mine lake (post-mining or reclamation situation)
Table 4 Evolution of the risk level according to the phases of exploi- tation, impoundment and redevelopment of the lake (LT) Mitigation measures the mining site. Mitigation measures, passive and active measures, can be recommended.
Table 4 Evolution of the risk level according to the phases of exploi- tation, impoundment and redevelopment of the lake (LT) Mitigation measures the mining site. Mitigation measures, passive and active measures, can be recommended.
Fig.5 Application of monitoring according to location and scale of hazard Fig.4 Risk management strategy of a mine lake
Fig.5 Application of monitoring according to location and scale of hazard Fig.4 Risk management strategy of a mine lake
the feared phenomenon (Klein et al. 2014). The choice of instruments and devices should be based on the hazard intensities and the site predisposition. It also depends on the local scale of application, generally well endowed with numerous instruments, and a larger scale (Fig. 5): lake, site and/or regional (multiple lakes) scale. Monitoring data, if well-monitored and analysed, are very useful and indispen- sable for risk management. Three levels of monitoring are recommended for a pit lake: low hazard: no monitoring, or, depending on the vulnerabilities present, minimal monitor- ing with few dedicated instruments and devices; Moderate hazard: localised monitoring in the most vulnerable areas; moderate-to-high hazard: localised monitoring of the most vulnerable areas with a warning system, and vigilance and alert thresholds. The thresholds of the monitoring param- eters must be defined pursuant to feedback from experience and a very good knowledge of the hazards on the site of the lake being monitored. The monitoring must, therefore, be based on procedures that are developed and followed by the various actors involved in the management of the lake site.
the feared phenomenon (Klein et al. 2014). The choice of instruments and devices should be based on the hazard intensities and the site predisposition. It also depends on the local scale of application, generally well endowed with numerous instruments, and a larger scale (Fig. 5): lake, site and/or regional (multiple lakes) scale. Monitoring data, if well-monitored and analysed, are very useful and indispen- sable for risk management. Three levels of monitoring are recommended for a pit lake: low hazard: no monitoring, or, depending on the vulnerabilities present, minimal monitor- ing with few dedicated instruments and devices; Moderate hazard: localised monitoring in the most vulnerable areas; moderate-to-high hazard: localised monitoring of the most vulnerable areas with a warning system, and vigilance and alert thresholds. The thresholds of the monitoring param- eters must be defined pursuant to feedback from experience and a very good knowledge of the hazards on the site of the lake being monitored. The monitoring must, therefore, be based on procedures that are developed and followed by the various actors involved in the management of the lake site.
Table 5 Summarized information from mine lakes—former coal mines Data GEM geometrical, GEL Geological, GET Geotechnical, HY Hydrological, CL Climatic, EX Exploitation, FL Flooding, WQ Water qualit VUL Vulnerabilities, GMT Ground movement
Table 5 Summarized information from mine lakes—former coal mines Data GEM geometrical, GEL Geological, GET Geotechnical, HY Hydrological, CL Climatic, EX Exploitation, FL Flooding, WQ Water qualit VUL Vulnerabilities, GMT Ground movement
Fig.6 Open pit lake management—Most lake—Czech Republic, before and after management (Credit of VUHU)
Fig.6 Open pit lake management—Most lake—Czech Republic, before and after management (Credit of VUHU)
Table 6 Identified mining and natural hazards of the Most lake N/A non—applicable
Table 6 Identified mining and natural hazards of the Most lake N/A non—applicable
Table 7 Probability weights of mining and natural hazards of the Most lake corresponding to low hazard. In addition, to the qualitative assessment, an advanced risk assessment was carried using a 3D—large scale numerical modelling, considering the geol- ogy and the presence of a weak layer (Renaud et al. 2022). The weak layer has very low friction angle. The result of the numerical modelling showed that the safety factor of the slopes is equal to 2.2 without considering the presence of the weak layer and close to 1.5 when weak layer is considered. Furthermore, in situ observations have shown local instabili- ties during the construction phase.
Table 7 Probability weights of mining and natural hazards of the Most lake corresponding to low hazard. In addition, to the qualitative assessment, an advanced risk assessment was carried using a 3D—large scale numerical modelling, considering the geol- ogy and the presence of a weak layer (Renaud et al. 2022). The weak layer has very low friction angle. The result of the numerical modelling showed that the safety factor of the slopes is equal to 2.2 without considering the presence of the weak layer and close to 1.5 when weak layer is considered. Furthermore, in situ observations have shown local instabili- ties during the construction phase.
Another option for risk level calculation is the consid- eration of the most significant hazards from each category. According to the literature, landslides and flooding are the most important from each category (Gul and Guneri 2019; Mohammady et al. 2019,). The risk calculation process was retained the same, considering only the relative hazards from each category. Figure 10 presents the risk level distribution
Another option for risk level calculation is the consid- eration of the most significant hazards from each category. According to the literature, landslides and flooding are the most important from each category (Gul and Guneri 2019; Mohammady et al. 2019,). The risk calculation process was retained the same, considering only the relative hazards from each category. Figure 10 presents the risk level distribution
Fig.9 Natural hazard level distribution R for 10,000 simulations Fig.8 Mining hazard level distribution (R) for 10,000 simulations
Fig.9 Natural hazard level distribution R for 10,000 simulations Fig.8 Mining hazard level distribution (R) for 10,000 simulations
Fig. 10 Landslide hazard level distribution ® for 10,000 simulations Based on the geology, the geotechnical data, the in-situ observations, and the calculation results (deterministic and probabilistic), we can consider the Most site presents a low to moderate slope stability hazard. One can observe that advanced and complete risk analysis corresponding to a quantitative method, using different data, can better assess the hazard and the risk class. The Most site was the subject of different earth and management actions to ensure safety and security for public and leisure employ- ment (Figs. 3 and 6), noticeably, stabilization elements for flanks and roads. The necessary extent of the necessary remediation interventions was elaborated: stabilization
Fig. 10 Landslide hazard level distribution ® for 10,000 simulations Based on the geology, the geotechnical data, the in-situ observations, and the calculation results (deterministic and probabilistic), we can consider the Most site presents a low to moderate slope stability hazard. One can observe that advanced and complete risk analysis corresponding to a quantitative method, using different data, can better assess the hazard and the risk class. The Most site was the subject of different earth and management actions to ensure safety and security for public and leisure employ- ment (Figs. 3 and 6), noticeably, stabilization elements for flanks and roads. The necessary extent of the necessary remediation interventions was elaborated: stabilization
Fig. 11 Flooding hazard level distribution (R) for 10,000 simulations
Fig. 11 Flooding hazard level distribution (R) for 10,000 simulations
Related topics:
Environmental ScienceEarth and Environmental Sciences
580 California St., Suite 400
San Francisco, CA, 94104
© 2025 Academia. All rights reserved