| dc.description.abstract | The plain of west Taiwan is formed of soft alluvium ground with a high groundwater level. As Taiwan is located on the Circum-Pacific Seismic Belt, earthquakes occur frequently and can lead to soil liquefaction on the alluvium ground. Sheet pile walls are often used as a retaining system at riverbanks, harbors, and piers due to their cost-effectiveness, convenience, and constructability. Near the river, soil deposits are composed of alluvial soils and groundwater levels are very high, therefore soil liquefaction are usually more common around this area. When soil liquefaction occurs, the sheet pile walls would fall or become damaged as a result of soil deformation. The frequency content distribution for each earthquake is varied under real conditions; earthquake shaking at different frequency contents will provoke different behaviours from the wall-soil system. In this study, four dynamic centrifuge tests were conducted to simulate the sheet pile wall constructed at liquefiable ground, subject to the base shaking at different frequency contents. The peak base acceleration of input motion for each test were 0.16 g, 0.15 g, 0.27 g and 0.08 g, with frequency contents of 1 Hz and 1+3Hz, 21 cycles of non-equal amplitude sinusoidal wave. The horizontal displacement of the sheet pile wall and ground surface induced by shaking were measured and tracked by the Linear Variable Differential Transformers (LVDTs) and surface markers.
The results revealed that in the same peak base acceleration, models subjected to an input motion with higher 3 Hz content has higher excess pore water pressure excitation, and larger pile lateral displacement, the rotation angles of the two wing plates of the sheet pile wall were 2.54° and 3.26° respectively, and the average ground surface movement towards the dredge area was 0.25 m. Models subjected to an input motion with lower 3 Hz content has lower excess pore water pressure excitation and excitation rate, and lower pile lateral displacement; the rotation angles of the two wing plates of the sheet pile wall were 2.54° and 3.26° respectively, and the average ground surface movement towards the dredge area was 0.18 m. | en_US |