Semi-quantitative risk analysis of high concrete face rockfill dams under seismic action

A dam failures cause immeasurable losses, but more concrete face rockfill dams (CFRDs) are being built in areas where earthquakes occur frequently. If the risk level of CFRDs under seismic action can be identified promptly and corresponding measures taken in advance, dam failure risks can be mitigated to protect life and property. However, no study has been conducted on the seismic risk analysis of CFRDs. This study aimed to meet public security needs; hence, the risk matrix approach was used for analyzing the semi-quantitative risk of CFRDs under seismic action. Considering the seismic failure modes of dam deformation and dam slope instability, we also proposed a calculation technique of seismic failure possibility for high CFRDs. According to the worst-case scenario, the linear weighted sum method was used to assess the comprehensive seismic risk loss of CFRDs in terms of life loss,and economic loss, and socio-environmental impact. The risk levels of CFRDs under seismic action were accurately evaluated, and corresponding risk management measures were proposed according to the “As Low As Reasonably Practicable” principle. The results of this work fill the gap in the risk analysis of CFRDs under seismic action. Additionally, the results provide a theoretical basis and technical support for future seismic designs, seismic risk assessments, and risk decision-making for high CFRDs and similar projects in strong seismic areas.