Aseismic and Anti-Tsunami Seawalls and Port Structures

Turkey, Japan, Chile, and the West Coast states of the United States are well-known for experiencing strong earthquakes from time to time. When hit by seismicity of a high magnitude, coastal and inland structures in these regions are easily destroyed not only by strong motions but also by earthquake-induced liquefaction of soil under them. The risk of potential liquefaction of seawall foundations is proven to be minimized by double sheet pile walls, which confine the soil in-between. A tubular pile wall installed inside a seawall also enhances its structural integrity during an earthquake and thereafter so the seawall will maintain its functions even if it is partially damaged. These two new designs and the projects that employed them in Japan as well as an aseismic levee upgrade project in California will be studied. These projects utilized the Press-in Piling Method to drive the piles without damaging the existing seawalls or disturbing local residents due to its low noise and very low vibration nature.