Filtration behavior and micro-observation of geotextiles under bi-directional cyclic flow

• Main Authors: Wen-Bin Chung, 鍾文彬
• Other Authors: 陳榮河
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/48523789180004927657

碩士 === 國立臺灣大學 === 土木工程學研究所 === 95 === This research utilized a bi-directional flow apparatus to probe into the filtration function of the soil-geotextile system under the actual water current condition. The content of this studty is a continuation of another research, state the reference, that emphasized the influence on filtration behavior of using different fine particle contents and overburden pressures. Furthermore, the soil samples in this study were composed of Vietnam sand with 5-15%fine material. Two kinds of overburden pressures were used: 70 kPa and 140 kPa. Also, four kinds of flow periods were adopted: 600, 300, 150, and 75 seconds per cycle. In addition, to understand the influence of the number of geotextile layer to the filtration behavior, this experiment has employed another case involving a double-geotextile layer. And, after above-mentioned methodology was completed, a stereomicroscope was utilized to observe the clogging condition in the geotextile. The results of the experiment are: (1) In all the test, boiling did not occur; (2) The fine particle contents and overburden pressures have shown influence to the degree of clogging of the soil-geotextile system; (3) It was found obvious that the dimension of overburden pressures influences the movement of the fine particle in the soil-geotextile system, and the the overburden pressure increment can limit the movement of fine particles; (4) The double-geotextile layering condition has served in slowing down the system’s settlement; and (5) Under the long-term stable bi-directional flow, the soil-geotextile system has chances of exhibiting a steady filtration layer temporarily.