Author(s)

C. Onisiphorou

Abstract

Retaining walls are commonly used in engineering practice for the retaining of soil masses that would otherwise be unstable. However, earthquake induced forces may trigger an instability or cause failure for a retaining wall. This can have major consequences for the case of tall retaining walls subjected to heavy traffic, and is thus the focus of this work. The present paper concentrates on the investigation of earthquake loading on tall retaining walls supported by an anchor force. The combined surcharge and ground motion effects resulting from earthquakes will be examined. A limit equilibrium model approach is used based on Eurocode 7, and the principles of Eurocode 8 with relevance to retaining structures are also adopted. A graphical solution is developed for the practicing engineer for the stability assessment of tall retaining walls under the combined effect of traffic surcharge and earthquake induced motion. Using simple charts, a stability factor is determined for the retaining wall. Keywords: seismic load, retaining walls, earthquake resistance, code design, Eurocodes, stability, surcharge load, graphical solution. 1 Introduction The design of earth retaining structures is important for minimizing hazards from ground failures or slope movement. Retaining structures must also be able to resist earthquake loading, resulting from strong ground movement in earthquake prone regions. Eurocode 8: Part 5 [1] addresses this issue by devoting a section on the earthquake resistant design of retaining structures, while the fundamental methods for stability considerations of retaining structures are included in EC7: Part 1 [2]. Both of these documents were adhered to, in the duration of the present work, as the author aims to follow through the recommended design procedure.

Keywords

seismic load, retaining walls, earthquake resistance, code design, Eurocodes, stability, surcharge load, graphical solution.