Numerical and Centrifuge Modeling of Gravity Wharf Structures Subjected to Seismic Loading

Abstract

Gravity wharf (GW) structures are gaining popularity in new port constructions, as well as expanding existing ports. When such structures are located on saturated alluvial seabed, their seismic performance needs to be established, particularly from a liquefaction point of view. In this paper, time domain finite element (FE) analyses were carried out on a typical GW structure cross section located on a 10-m-thick saturated sand bed. In addition, the same cross section was tested in a geotechnical centrifuge and subjected to earthquake loading. The results from the FE analyses were directly compared with the centrifuge test data. Firstly, the settlement and rotation of the GW structure when subjected to a series of earthquake loadings were compared. It was shown that the FE analyses were able to capture the level of settlements quite accurately. Similarly, the dynamic responses of the GW structure observed during the centrifuge testing were compared with the results from the FE analyses. Finally, the excess pore pressures generated in the sand bed were compared with the experimental data. In addition to the centrifuge testing, the FE analysis was able to provide the spatial redistribution of the vertical effective stresses with the onset of excess pore pressure generation. Similarly, the excess pore pressure ratio contours could be constructed at any given time point. In combination, the results from the FE analyses and the centrifuge data concluded that the GW structures could perform well, even under strong earthquake loading with acceptable settlements.