碩士 / 國立成功大學 / 水利及海洋工程學系 / 88 / Abstract
Previous several wave flume studies on wave-induced seabed responses indicate certain relationships between seabed’s fluidization and soil’s constituent particle sizes. In addition, near bed suspended sediment activities are closely related to seabed’s instability. Thus, in this thesis, a fine sand (D50 = 0.069 mm) is used as test seabed material to investigate the links between internal soil fluidization response and the near bed suspended sediment concentrations. In the experimental tests, an optical concentration probe near above bed and 5 probe pressure transducers were applied for simultaneous measurements of both quantities. The pore pressure measurements show that the fine sandy seabed could be fluidized under wave loading. Compared with Sue’s (1999) tests with sands (D50 = 0.085 mm), it immediately illustrates that typical responses are similar to those defined by Sue as unfluidized, initially fluidized and continuously fluidized, respectively. But, there are more fluidized test runs in present fine sandy beds, especially most initially fluidized response occur in the first run. The measurements show that the values of suspended sediment concentration used to increase significantly short after seabed is fluidized. For the same test, the maximum values of suspended sediment concentration are largest in the initially fluidized runs and the values decrease in consecutive runs as shallower soil layer are fluidized. Essentially, only very low suspended sediment concentrations are detected in the unfluidized response. As a result, this study has for the first time preliminarily confirmed the direct relationship between seabed fluidization and near bed suspended sediment concentration while fine-grained sediments are more potentially fluidized. It is suggested that practical models of suspended sediment concentration should be modified by taking into account of the seabed responses.
Keywords: regular waves, fine sandy soils, seabed fluidization, suspended sediment concentration.
| Identifer | oai:union.ndltd.org:TW/088NCKU0083023 |
| Date | January 2000 |
| Creators | Wen-Chang Peng, 彭雯章 |
| Contributors | Shan-Hwei Ou, Shiaw-Yih Tzang, 歐善惠, 臧效義 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 70 |
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