Seismic Assessment of a Dam on a Clayey Foundation

Olaya F.R.; Cañabi L.M. · Geotechnical, Geological and Earthquake Engineering (2022) · DOI: 10.1007/978-3-031-11898-2_179

Resumen

The seismic performance of a rockfill dam founded on a 20 m clayey foundation layer is presented. This stratum is the foundation of a 45 m high rockfill dam. A specific site seismic hazard study indicates that a Mw 8.0 event with peak ground acceleration of about 0.45 g is appropriate for design. The final aim of this ongoing study is to study the fragility of the dam-foundation system. The geotechnical characterization of the foundation involved the in-situ measurement of index properties (e.g., water content and PI) and the retrieval of undisturbed samples. Next, a battery of compressibility and strength testes were performed. The inferred compressibility characteristics of the clay layer and the measured monotonic stress-strain curves allowed the calibration of the modified Cam-Clay model. For the dynamic evaluation, a series of monotonic and cyclic direct simple shear tests results representative of this clay layer were collected to calibrate the PM4Silt model. Shear wave velocity profiles allowed the dynamic characterization of the core material and rockfill shells for which the UBCHyst model was employed. The static and dynamic analysis results are presented in terms of permanent deformations for design level motions. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.