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碩士論文公告區 |
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| 年度： | 96 | |
| 姓名： | 張家銘(Chia-Ming Chang) | |
| 論文題目(中)： | 柔性攔截網於土石流防治之成效分析 | |
| 論文題目(英)： | Study on Flexible Steel Net Applied to Debris-Flow Hazards Mitigation | |
| 摘要(中)： | ||
| 土石流災害防治的觀念，傳統上是以混凝土結構剛性抵擋的觀念設計，如攔石柵欄或鋼筋混凝土重力壩等較為剛性之防護設備，但皆耗費相當大之經費；而柔性攔阻系統於歐美各國已使用有年，除落石災害防治外，亦使用於雪崩及土石流等災害，在國內使用柔性攔阻系統攔阻土石流實為少見，故為土石流攔阻工程中之重要課題。 本研究於南投縣水里鄉上安村三廍坑溪上游現地架設柔性攔截網，攔截網完工後，曾有多次颱風造成當地連續性豪大雨，引發土石流災害，而攔截網分別攔下多次土石流，經多次攔阻後，堆積之土石呈現溢滿攔截網之狀態。本研究將現地勘察土石流淹沒情況與柔性攔截網實際攔阻情況，並且配合室內水槽試驗結果互相驗證，探討柔性攔截網之土砂堆積情況、貯砂率、體積濃度減少率、無因次土砂流出比、彈簧變化及震動計變化等土石流防治成效之重要參數。 由現地觀測與室內水槽試驗結果顯示，柔性攔截網在多次土石衝擊後，能夠有效地使溪床坡度變緩，減弱下一波土石向下移動之動力，使土砂將逐漸往上游堆積。在體積濃度減少率方面，各組試驗通過攔截網後體積濃度都降至0.2以下。無因次土砂流出比在高體積濃度時為最佳達0.012，表示土石流在體積濃度低時，流動能力較佳，帶過攔截網的土石也越多。彈簧變化及震動計變化分析結果顯示，柔性攔截網在攔阻土砂後將產生自重形成透水石籠之功能，有效降低下波土石之衝擊力。經由探討現地與室內水槽試驗結果得知，柔性攔截網能有效地減低土石流之體積濃度、土砂流出量、衝擊力及破壞力，達到土石流防治之目的。 |
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| 摘要(英)： | ||
| For concept of debris-flow hazards mitigation, traditionally, the protective equipment, which is designed based on the rigid retaining concept of concrete structures (such as debris barrier or reinforced concrete gravity dam), costs large sums of money. However, the flexible steel system has been used in Europe and U.S. for many years. In addition to the rock-fall disaster prevention, it also can be used in such disaster as snow-slide or debris flow. It is seldom seen that the flexible steel system is used to block debris flow in Taiwan. Therefore, this research will make a further study on the flexible retaining system is an important issue in debris-flow hazards mitigation construction. The flexible steel net was installed in the upstream of Shan Pu Keng River, Shanan Village, Shueili Township, Nantou County. After flexible steel net set up, there were some typhoons which caused heavy rainfall leading to debris flows. The flexible steel net blocked the debris flows individually. After that, rocks and sediments filled in the flexible steel net. In this research, the depositions of debris flows and situations of block of flexible steel net, as well as compare with the results of flume tests in Lab to discuss the situations of sediments, grain deposition rate, volume concentration reduction rate, sediments flow rate, change of spring and change of vibration meter, etc. From observation of field and flume tests in Lab, it can be found that the slope of river bed become smooth and the impact force of debris flows decreased make debris accumulate gradually in upriver after flexible steel net is struck again and again by debris flows. For the volume concentration reduction rate, the results of flume tests in Lab shows that the volume concentration for all cases after passing the net is reduced to below 0.2. Volume concentration, 0.012, in the sediment is better than in the higher the volume concentration, which means that when debris flow is in the lower the volume concentration, the power of flow is great and more debris can pass flexible steel net. The analytic results of spring elongation and vibration meter illustrate that flexible steel net form function of rock gabion after flexible steel net block debris. Due to the retaining structure produced, which can effectively decrease impact force of the next debris flow. Through the results of field observation and flume tests in Lab, they can be known that flexible steel net can effectively decrease the volume concentration of debris flow, the amount of flow of debris flow, the impact force and the destructive force, to reach the destination of debris-flow hazards mitigation. |
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| 檔案： | 沒有相關檔案 | |
| 相關連結： | http://ethesys.lib.cyut.edu.tw/ETD-db/ETD-search-c/view_etd?URN=etd-0828108-124452 | |