Numerical Assessment of the Deformation of CFRD Dams during Earthquakes

Author(s): 
Alejo Sfriso
Date: 
Monday, October 6, 2008
First presented: 
12th International Association for Computer Methods and Advances in Geomechanics, India.
Type: 
Published paper
Category: 
Geotechnical

A numerical procedure for the preliminary estimation of the earthquake-induced settlement of concrete face rockfill dams is presented. The method is based on a simple constitutive model that accounts for the key features of the behavior of coarse grained materials that affect the response of CFRDs, namely pressure dependent elasticity and a peak friction angle dependent on both pressure and void ratio. The actual earthquake design record is replaced by a simple sinusoidal base acceleration having an equivalent effect on the dam. The numerical model uses isotropic hyperelasticity and isotropic hardening/softening plasticity combined with stressdilatancy theory, and thus is applicable to geometries and materials where only monotonic plasticity is expected to occur, as is the case of CFRD dams. A case study is presented where the procedure is applied to a CFRD 140 m high, located in Argentina and designed for a strong earthquake. The computed settlement compares well with an analytical estimation and with a decoupled numerical model of the same problem. The main advantage of the proposed procedure is that all material nonlinearities are accounted for by the constitutive equations, thus allowing for the usage of a simple mesh with no artificial sub-zonification.

Feature Author

Alejo Oscar Sfriso

Alejo O. Sfriso is a Principal Engineer with 25 years of experience in geotechnical engineering for infrastructure and mining works. He is an expert in the application of numerical methods for geotechnical design and analysis. In addition to his activity at SRK, he is the Director of AOSA - Geotechnical Laboratory, Professor of Soil Mechanics and Geology of the University of Buenos Aires, Vice President for South America of the International Society of Soil Mechanics and Geotechnical Engineering for the period 2017 - 2021, former Professor of Geotechnics at the National University of La Plata and former President of the Argentinean Society of Geotechnical Engineering.

Principal Consultant
PhD, Civil Engineer
SRK Buenos Aires
SRK North America