Investigation of seismic damage to reservoirs and total risk assessment of dams in earthquake-stricken area during Lushan Earthquake

A field survey was conducted within the earthquake-stricken area to investigate the damages to dams and reservoirs caused by the Lushan M 7.0 earthquake. Based on the survey results, a preliminary damage evaluation of 9 selected reservoirs in Baoxing and Tianquan counties was also performed. Field survey indicated that typical damages to these dams included the deformation and failure of subsidiary structures, dam seepage, and indirect damage caused by geological disasters such as landslides and collapse, whereas the main structures of most dams remained intact or largely intact. To further analyze potential risks to dams caused by the earthquake, the risk analysis method of Bureau (2003) was modified to dam height risk factor and downstream hazard factor based on dam construction, local economy, and population, and employed to calculate the total seismic risks of 19 dams in the quake-hit areas. Result indicated that the overall risk level of the dams in the earthquake-stricken area ranked moderate, which was consistent with the field investigation results. The total seismic risk analysis can be useful for further damage assessment and post-quake reinforcement of dams. ©, 2015, Editorial Department of Journal of Sichuan University. All right reserved.