MECHANISM OF DEFORMATION AND FAILURE OF GRAVITY-TYPE QUAY WALLS UNDER EARTHQUAKE LIQUEFACTION

The field investigation found that seismic damage to gravity-type quay walls during Kobe earthquake consisted of tremendous lateral displacement of retaining walls. It is very important to clarify the mechanism of the wall displacement in order to improve the aseismatic design. For this purpose, a model of gravity-type quay wall ground based on the principle of similitude was designed and a series of shaking table tests are carried out in present study. The test results indicate that the strength decrease and local liquefaction of subsoil are the leading factors in the deformation and failure of retaining walls. The increase of dynamic earth pressure in the back of structure provides the movement condition for the structure. While the movement of the ground mainly manifest as the lateral displacement under liquefaction and the gravity is the leading factor in the lateral movement. It is very significant that the dynamic earth pressure is decreased and the foundation sand is fully compacted to increase the stability of gravity quay walls during future earthquakes.