Safety analysis of rockfill dams based on crest seismic settlement with intelligent parameter imputation and grey relational analysis

Crest settlement is a key indicator of seismic deformation in rockfill dams. However, the absence of a dedicated seismic settlement database and the incomplete recording of key parameters hinder systematic assessments of seismic damage. To address these limitations, this study develops a comprehensive database documenting crest settlement and associated dam damage. A novel Data–Physics Hybrid-Driven (DPHD) imputation method is introduced to reconstruct missing parameters, and its accuracy is rigorously validated. Single-factor analyses elucidate the mechanisms governing crest settlement, whereas grey relational analysis identifies the dominant influencing factors—namely, dam resistance, seismic-acceleration intensity, near-field effects, and epicentral distance. Based on the database and analytical results, seismic-settlement control standards corresponding to different damage levels are further proposed. The results demonstrate that the DPHD method effectively resolves data gaps, and the derived settlement standards provide practical guidance for seismic design and settlement-mitigation strategies in rockfill dams.