Review of seismic design of slopes and retaining walls using limit state design methods and numerical analyses

Abstract

Earthquakes are one of the most commonly occurring and dangerous natural hazards on this planet. While geotechnical earthquake engineering is a research area that studies the behaviours and conducts proper designs of geotechnical structures under seismic loading. This research has a particular focus on slopes and retaining walls and design guidelines are following the up-to-date second generation of Eurocode 8. In order to build a complete picture of seismic design, relevant previous studies in Hong Kong have been reviewed. Seismic hazard studies have been conducted for the design spectrum of ground motions. To obtain the dynamic soil properties, which mainly is the shear wave velocity of the soil, various in-situ field tests and laboratory tests can be done for the purpose. For numerical analyses, numerous methods including Sarma’s method, Newmark’s sliding block method and finite element method have been conducted to study the slopes under seismic loading. On the other hand, for studying retaining walls, dynamic earth pressures have been calculated according to the Eurocode 8, and subsequently, permanent displacements and rotational angles of corresponding instabilities can be examined by Au-Yeung & Ho’s method and finite element method. Results show that the slope model with stiffer soil or less slope inclination angle will be more stable. At the same time, the retaining wall model with stiffer soil or larger embedment depth will become more stable under seismic loading.