Numerical methods for estimating seismic retrofit effect of SG-Wall method

A new technology (SG-Wall) was proposed for the target of seismic retrofit and front-water-depth-increase for quay walls. It is a combination of stabilization technique of dredged material and geosynthetics. In order to verify its seismic retrofit effect, a 1/24 model test utilizing an underwater shake table was conducted. In this paper, two methods were proposed for evaluating the seismic stability of marine structure with SG-Wall. One method is a simple method based on the Newmark method and considers the characteristic of earthquake wave. And the other one is dynamic effective stress-based FEM, which uses a new subloading Cam-clay model and soil-water coupled analysis technology. It is found that both methods are not sophisticated enough for practical design, and further study should be continued. Although two types of SG-Wall method (caisson type and sheet pile type) were proposed and tested in shake table tests, only the caisson type was considered here.