Dynamic p-y curves of pile-soil under complex structure-pile-soil system

Shaking table tests on complex structure-pile-soil interaction are accomplished for the transport junction of Tianjin Station, and dynamic properties of pile-soil interaction are studied. The time history of moment and soil pressure are obtained from the theory of elastic foundation and the displacement of pile is acquired through integral of pile acceleration measured from the tests, and then dynamic p-y curves of pile-soil are obtained. The distribution rules of damping and spring stiffness coefficient at different depths during different periods are calculated. It is shown that the distribution of damping and spring stiffness coefficient along the pile can approximately be taken as piecewise linearization, and the turning point is at about 1/3 length of the pile from the top. Both the damping and the spring stiffness coefficient increase with the increase of pile depth; and with the continuous vibration, damping is stable along the pile except slight increase at the bottom of the pile while the spring stiffness coefficient decreases continuously, and the decrease magnitude is expanded as the depth increases.