STUDY ON THE EFFECT OF GROUND MOTION CHARACTERISTICS ON SEISMIC RESPONSE OF A CANTILEVER WALL

Abstract

Earthquake is one of the most efficient loads to impact engineering structures. In the seismic investigations and design of structures, how to select the actual seismic record as input has been a very significant problem in earthquake engineering applications. Despite numerous studies that have been fulfilled over the years, the seismic responses of cantilever retaining walls, and several aspects of their behaviour are poorly understood. The earthquake response of the cantilever retaining walls is also known to be affected by many factors such as soil-structure interaction phenomenon, the soil stiffness, the frequency content of the ground motion, rocking base compliance, translational flexibility of the wall foundation, the rigidity of the cantilever retaining wall. In recognition of the requirement to consider the three dimensional nature of the soil-structure interaction system, a finite element analysis based procedure has been established in this study. In this context, the study aims to shed light on the ground motion effects on the dynamic response of a cantilever retaining wall with a base key using the finite element model considering soil-structure interaction. The viscous boundaries are used for eliminating the reflection of wave energy at the model soil boundaries. Seismic analyses are performed considering four different foundation soil systems, and the ground motion effect on the dynamic response of the cantilever retaining wall is investigated using stress and horizontal displacement variations of the wall under two different ground motions. In the seismic analysis, backfill-cantilever wall-foundation/soil interaction system is excited by considering C02065 component of the 1966 Parkfield, and the C-OLC360 component of the 1983 Coalinga earthquakes. The results show that the displacements and stress values of the wall are considerably affected from the ground motion characteristics in spite of the same structural properties and soil conditions. Furthermore, it is worth noting that the ground motion characteristics are one of the most important parameters while checking actual earthquake damage and explaining the damage mechanism.