New ideas for reducing seismic displacement of gravity quay walls

Very large deformation and displacement of quay walls are the main reason for failure to perform during strong earthquakes. A new idea is examined for reducing the seismic displacement of gravity caisson type quay walls using 1 g shaking table tests. Two types of displacement reducing elements are introduced and were used in the 22 model tests performed. These reducer elements consisted either of panels of synthetic plastic materials or cylindrical dissipaters that were placed between quay wall and a soft sheet pile. The panels and dissipaters were designed so that they could bear the static earth pressure, while they behaved like a fuse during the application of base shaking to prevent increase in dynamic earth pressure. The behavior caused a remarkable reduction of the wall movement. Test results, as well as the mechanism that governs the reduction of the seismic displacement, are presented and explained in this paper.