Seismic behaviour of pile groups in sloping ground

Publication Title
Seismic behaviour of pile groups in sloping ground

Abstract

With growing interest in offshore energy infrastructure, the seismic stability of structures founded on relatively shallow submarine clay slopes has gained significant attention. These slopes, typically less than 10°, are common in coastal areas supporting wharf structures and quay walls as well as on riverbanks where bridge abutments are founded. While stable under static conditions, they have been associated with large-scale failures under seismic loading. Despite extensive research on pile behaviour in liquefiable sands that suffer lateral spreading, limited attention has been given to pile foundations in soft clay deposits and layered soils. This study investigates the dynamic response of 2×2 pile groups embedded in gently sloping soft clay overlying dense sand. Dynamic centrifuge tests were conducted at Schofield Centre, University of Cambridge on slopes of 3° and 6° under varying seismic intensities and frequencies. Two test configurations, one with negligible pile cap mass and another with substantial mass enabled isolation of kinematic and inertial effects. The results focus on bending moment distributions along pile depth, with particular emphasis on the influence of slope angle.

Authors
Sulakna Weerasuriya; P. Gopal MADABHUSHIS

Published In

11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)

Theme

Special Session 2: Seismic behaviour of offshore foundations from dynamic centrifuge testing