**5. Conclusions**

In this study, 2D nonlinear effective stress dynamic analyses have been carried out to inves‐ tigate the seismic behavior of gravity-type quay walls. A reference model has been constructed and then subjected to seismic loading. The Finn and Byrne model has been adopted with some slightly modifications which take into account the pore water pressure generation and liquefaction process under dynamic loading. The numerical model has been validated by simulating 1g shaking table test. It is shown that the obtained numerical results agree reason‐ ably with actual observation in the shaking table test. The seismic response of the gravity wall itself has well captured by the numerical analyses with satisfactory predictions of acceleration, displacement, total pressure and pore water pressure time histories. Additional computational parametric studies have been conducted by varying backfill soil relative density, shear modulus, friction angle and maximum amplitude and frequency of input excitation to study the extent of liquefaction and deformation mechanism of quay wall system. It is concluded that soil properties and input motion characteristics are among the most influential factors in dictating seismic performance of the quay wall system. The results show that the backfill in the soil-wall interaction zone and the foundation soils beneath the quay wall experiences less excess pore water pressure even liquefaction occurs in the far field during shaking. The alternative pumping and suction process in excess pore water pressure which are caused by wall's vibrations increase the level of damage because large amounts of backfill are forcedly leaked into the sea. The lack of backfill liquefaction near the wall is attributed to the lateral displacement of the wall. In the other words, excess pore water pressure does not attain 100% liquefaction behind the quay wall contrary to the far field. The current study states that the numerical simulation incorporated with the special numerical techniques is capable of modeling the seismic response of gravity-type quay walls.
