Risk assessment and management for an extreme accident at a waste slag site

Abstract. Waste slag failure is a disaster that affects both the environment and people. In China there are many waste slags after the engineering project such as railway and road. Although the disposal of the waste slags obeys the regulations the government have established, some accident still happened. Therefore, we need to do inverse analysis to check the failure extend and impact area of each slope. The probability of failure of a waste slag site involves many unpredictable factors that are hard to calculate. Therefore, we propose a risk analysis and management scheme for extreme accidents that assumes failure will arise at extreme conditions, and emphasize risk management in the design and monitoring of the slag site. In this scheme, we use Tsunami–Square Method to simulate the flow of tailings sand to get the intensity parameters (flow path and thickness) to create hazard zones based on dam failure. The risks to buildings and people were analysed according to the vulnerability of the buildings in the flow path. A risk sharing community risk management mode is presented using the idea of Canadian Whitehorse Mining Initiative, which sparkplug multi-stakeholder representatives to participate in risk management. Following the As Low As Reasonably Possible principle, the risk management scheme divides areas at risk into five zones in the F–N Curve. These zones have different mitigation measures for risk from tailings ponds and other waste slag sites. The scheme is effective for determining design safety factors, implementing reinforcements, and monitoring the waste slag site, and encouraging multiparty participation in risk management.