Study on holding capacity of sandy-seabed anchors for marine aquaculture

• Main Authors: Sheng-hai Wu, 吳聖海
• Other Authors: Huang, C.C
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/17873027772631976573

碩士 === 國立中山大學 === 海洋環境及工程學系研究所 === 94 === In this study, the holding capacity of anchors and their design methodology are investigated. In general, three kinds of anchors have been used in cage aquaculture engineering, including embedment anchors, deadweight anchors, and pile anchors. The maximum holding capacity of embedment anchors was analyzed via the results of experiments by increasing the weight of anchors, while the best holding capacity of deadweight anchors was investigated by changing the types of shear keys. Moreover, the designs and considerations of pile anchors were also discussed in Appendix A. From the results of experiments, the maximum holding capacity of embedment anchors varies 12~19 times of their self-weight, and has the trend such as the holding capacity is in proportion to the weight of anchor. In the case of deadweight anchors, two methods were used to analyze the holding capacity, one is to consider the passive earth pressure behind each shear key of anchor block, and the other is to consider the net weight including the confined sand trapped inside of shear keys and its passive earth pressure at the outmost skirt key. It seems that the first method has more accurate than the second method until the number of keys equals 5 based on the experimental results. And, when the number of keys is greater and equal 6, the second method has better predictions than the first one. The main reason is that it is unable to fully develop the passive earth pressure in such a narrow space between the keys. Therefore, the interval between shear keys should at least equal 1 time of the key’s penetration depth according to this study.