Seismic Evaluation of Gravity Quay-Wall Structures, Subjected to Near- Fault Ground Excitations

In seismically active zones, earthquake excitations have to be considered in the design of coastal and port structures. Near-field earthquakes differ from those far to the fault in many respects,such as duration time, PGA, PGV, PGD, rupture directivity, fling step and pulse properties. Nearfaultearthquakes are usually characterized by a large high-energy velocity pulse. This impulsive excitation is mostly oriented in a direction perpendicular to the fault, causing the fault-normalcomponent of the motion to be more severe than the fault-parallel component [1]. Recent near-field earthquakes, including the 1995 Kobe Japan, 1999 Kocaeli Turkey, 1999 Chi- Chi Taiwan revealed sever damages in specific bridges, quay-walls and multistory buildingslocated near to the shaking fault. It was reported that the dynamic characteristics of the damaged structures were close to the characteristics of the rupture directivity and fling pulses [2, 3]. This paper reports results from a numerical investigation into the behaviuor of gravity quaywallssubjected to near-field earthquakes. The performance of the gravity quay-wall structures under ordinary ground excitations was already addressed by a number of researchers [4]. However, to the best of the author's knowledge, the behaviour of these structures under nearfield ground excitations has not been particularly received attentions in the literature.

Keywords:

Coastal Structure , Gravity Quay-Wall , Near-Fault Earthquake , Incremental Dynamic Analysis