The study of the influence of different drainage for seabed stability under wave action

• Main Authors: Chi-Ling Yang, 楊麒陵
• Other Authors: Lien-Kwei CHIEN
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/48458576899176204252

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 96 === This study from the ocean geotechnical viewpoint, selects in Yun-Lin marine cable station, western coast of Taiwan as studying area. The marine meteorological data was collected and jointed with wave theory. A series of partial drained dynamic triaxial test were performed to understand the stability of marine cable under wave induced wave loading. In order to understand the true behavior of the strength of sea bed soil under wave action, the field sands in Yun-Lin were adopted in the study. The specimens were prepared by multi-pluviation through water method to simulate the particle aggregation in-situ. The marine soils stress states were simulated by Ko consolidation in laboratory. Moreover, the stability of marine sands is discussed under different drain states by using flow valve to control the soil drains state. In this study, the typhoon waves induced loading were simulated in small amplitude wave and Stoke’s second order wave theory to evaluate the cyclic stress ratio in sea bed. From the test results found that the cyclic stress ratio in typhoon wave (as 100 years return period) by small amplitude wave theory, the soil resistances of sea bed is only 36 seconds. However, the marine soil was liquefaction immediately by using the Stoke’s second order theory. The drained efficiency is defined in this study. The relationship between strain and cyclic numbers, and cyclic stress ratio (CSR) were discussed under different drained efficiency conditions. From the results indicated that the drained efficiency have significantly influence on deformation resistance of sea bed soil. Therefore, the study analysis could be provided the reference for near shore structure design and engineering practice, and reduce storm induced damages.