| dc.description.abstract | Taiwan is located at the convergent zones between the Philippine Sea Plate and the Eurasian Plate. Such a complicated convergence has caused frequent earthquakes. The earthquakes probably triggers submarine landslides and then generates near-source tsunamis. Submarine landslides may destroy underwater infrastructure, causing huge economic losses, the tsunami could also be a serious threat to the coastal communities and infrastructures. In 2006, submarine landslide occurred offshore Pingtung; sediments impacted and broke submarine communication cables, affecting international communications and electronic transactions and causing economic losses. At present, the information on the process and deposition of submarine landslides is often limited. This study tries to observe deformation behaviors of submerged gentle slope by centrifuge modeling.
This study conducted five dynamic centrifuge modeling tests to simulate the deformation behaviors of submerged gentle slope by NCU geotechnical centrifuge at 40 g acceleration field. Simulating the failure behavior of submerged slopes with submerged gentle slope. The silica sand is selected for preparing the slope with target relative density of 30%. A submerged gentle slope with 10 m in height is modeled in this study. The slope of the test 10°and 20° A five dynamic centrifuge modeling tests with a frequency content of 1 Hz and 15 cycles sine wave. In this study, accelerometers, pore water pressure transducers, linear variable displacement transformers (LVDTs), surface markers, and spaghetti are arranged to observe the deformation behaviors of submerged gentle slope.
From the test results, it shows that: (1) Under the condition of 10°submerged gentle slope and input base shaking(CAV=9.11 m/s), the maximum surface displacement is about 2.28 m, and the slope after the earthquake is about 2°. (2) Under 10°slope gradient, the cumulative absolute velocity is 4.23 m/s and 9.11 m/s (increased by 2.15 times), the maximum surface displacement is 1.80 m and 2.28 m (increases by 1.26 times), After the earthquake, the slope of the test is 6.6 º and 2.4 º. (3) Under the different slope gradient(10º、20º), when t the cumulative absolute velocity is 7.21 m/s and 9.11 m/s (increased by 1.26 times), the maximum surface displacement is 2.28 m and 2.78 m. | en_US |