Feasibility Study on Man-madeContinuous Sliding in Submerged Sediment Slope by Jet Cutting Method

• Main Authors: Yen-chun Liu, 劉彥君
• Other Authors: Hung-Jiun Liao
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/02519143021356489600

碩士 === 國立臺灣科技大學 === 營建工程系 === 102 === Recently, the rapidly increasing amount of in-flow sediment to the reservoir behind the dam has become a serious issue for the dam operation authority in Taiwan. Large effort has been made to find out effective ways to remove the sediment from the reservoir and to allow more reservoir volume for water in case of extreme weather condition. Despite all the efforts, the sediment volume removed annually from the reservoir (~4.5 million m3 per year) is by far less than the in-flow volume of sediment (~ 18 million m3 per year). The water storage capacity of reservoirs is decreasing every year. More effort is needed. This research is to propose a method to create a group of jet cutting trenches in the sediment by high pressure water jetting. The layout of trenches is designed to trigger a chain-reaction type underwater landslide in the sediment. The sediment loosen by landslide will be brought out of the reservoir through the sediment discharge tunnel while discharging the excess water from reservoir during typhoon. To study the feasibility of the proposed method, a series of numerical studies was carried out in this research. The parameters studied include the location, dimension, and amount of pre-cut trenches in the sediment layer. Once the landslide is initiated, it will be followed by a chain reaction of continous landslides. It can help moving a large quantity of sediment toward the sediment discharge tunnel and hence increasing the efficiency and effectiveness of removing sediment from the reservoir.