Towards Displacement-Based Seismic Assessment of Concrete Dams Using Non-linear Static and Dynamic Procedures

Abstract

The current paper demonstrates the application of a displacement-based procedure in the seismic safety assessment of large concrete dams. Two dam structures, double arch and gravity, are used as case studies and analyzed through conventional force-based approaches for various seismic levels. Non-linear static analyses are used for the assessment of structural capacity and non-linear dynamic analyses—to obtain the maximum response for each seismic level. The safety of the dams is assessed through displacement-based damage indicators in the form of damage indexes (DIs) and safety factors (SFs). The DI accounts for the accumulated inelastic deformations in the structure and is related to pre-defined damage levels (DLs), while SF evaluates the structural safety margins in terms of seismic load intensity. In addition, the paper provides an assessment of the applicability of non-linear static procedures (NSP) for seismic assessment of large concrete dams. The results obtained from NSP for seismic level maximum credible earthquake (MCE) are compared with a set of ten dynamic non-linear analyses for the same seismic intensity. NSP results tend to give a more conservative prediction, but are still consistent with the results calculated via non-linear dynamic analyses.