Seismic analysis of reservoir-gravity dam-massed layered foundation system due to vertically propagating earthquake: Fid-Bau Portal

Seismic analysis of reservoir-gravity dam-massed layered foundation system due to vertically propagating earthquake

Sotoudeh, Payam / Ghaemian, Mohsen / Mohammadnezhad, Hamid

Abstract Seismic analysis of complex structures such as concrete dams has been the subject of numerous studies. One of the challenges in seismic analysis of such systems is proper modelling of massed foundation. Since concrete dams’ foundations are usually layered, this makes the homogenous half-space assumption relatively unrealistic. In this paper, the effects of massed layered foundation on seismic response of concrete gravity dams in dam-reservoir-foundation systems are investigated. Seismic finite element analysis of the system carried out using domain reduction method. This approach is compared with another available method named, free-field column. First set of analysis considers the effect of modular ratio between layers on seismic response of the gravity dam. Second set of analyses investigate the effects of layers’ geometry, location and orientation on obtained responses. Results highlight the considerable effects of massed layer foundation assumption against its homogenous counterpart. Besides, results show that layer properties dictate how severely they can affect the dynamic responses of the dam.

Highlights • Massed layered foundation assumption can have considerable effects on response of dam. • Domain reduction method and free-field column method were used for analysis. • Dam response is more prone to drastic changes at lower modular ratios. • Layers’ thickness, property and location affect the response more than other factors.