| 姓名 | 洪政宏(Hung-Cheng Hung) | 電子郵件信箱 | E-mail 資料不公開 | |
| 畢業系所 | 營建工程系碩士班(Department and Graduate Institute of Constrction Engineering) | |||
| 畢業學位 | 碩士(Master) | 畢業時期 | 95學年第2學期 | |
| 論文名稱(中) | 柔性攔截網壩之土石流防治功效評估 | |||
| 論文名稱(英) | The evaluation of flexible retaining structure applied to debris-flow hazards mitigation | |||
| 檔案 |
請遵守中華民國著作權法之相關規定，切勿任意重製、散佈、改作、轉貼、播送，以免觸法。 |
論文使用權限 | 校內外均一年後公開 | |
| 論文語文/頁數 | 中文/95 | |||
| 摘要(中) |
土石流的破壞力來自於其大量的土砂與快速的運動衝力，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之重力壩等較為剛性的防護設備，但皆耗費相當大之經費，其結構安全考量必須特別注意；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，故本研究將柔性攔阻系統作進一步之研究探討。 本研究所採用之攔截網壩為兼具透過性柔性吸能構造物與透水石籠壩之功能，當土石尚未堆滿攔截網時為柔性吸能網之功能，當土石堆滿攔截網壩時則以其自重形成石籠壩。配合國科會小產學計畫，於南投縣水里鄉上安村三廓坑溪上游現地架設土石流攔截網壩，進行土石流攔阻功效評估，並將攔截網壩縮小尺寸，移至室內做土石流水槽試驗。室內土石流試驗以等重量替代法模擬現地級配狀況，測量河床平均坡度，以不同土石流體積 濃度及不同最大粒徑下，探討其攔阻效果及受力狀況，分析項目有體積濃度減少率Rv、過壩率Rp、貯砂率、震動計及位移計等。 室內水槽試驗結果顯示，在體積濃度減少率方面，各組試驗過壩後體積濃度都降到0.3以下，在初始體積濃度為0.45及0.55時，體積濃度減少率都有80%以上；初始體積濃度0.35時體積濃度減少率為60.3%。而體積過壩率隨體積濃度增加而減少，在未滿壩之前都低於40%。貯砂率則以高體積濃度越時候最佳，體積濃度0.65時可達到98.88%；在體積濃度0.35時，貯砂率下降至最低有60%。位移計及震動計在多次土石流衝擊下，在土石堆積於副壩及壩前時衝擊力及壩體加速度明顯降低，所以經試驗得知攔截網壩確實可以利用其特性攔阻土石流。 |
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| 摘要(英) | The
destructive power of debris flow comes from a large number of
soil & sediment and rapid movement & impulse. 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.
We must pay attentions to its structure safety especially. And
the flexible retaining 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 snowslide or
debris flow. It is seldom seen that the flexible retaining
system is used to block debris flow in domestic areas.
Therefore, this research will make a further study on the
flexible retaining system. The retaining structure adopted by this research has both functions of a permeably flexible energy dissipation structure and a previous rock gabion dam. As it is not full of soils and sediments in the retaining structure, then it is the function of flexible energy dissipation structure. As it is full of soils and sediments in the retaining structure, then it becomes the function of rock gabion dam naturally. In coordination with the Program to Upgrade Industrial Technology and Enhance Human Resources of National Science Council, we set up an on-site debris-flow retaining structure in the upstream of Shan Pu Keng River, Shanan Village, Shueili Township, Nantou County to assess the effect of such debris-flow retaining structure and to shrink its size to move to the indoor for a test of debris-flow tank. For the indoor debris-flow test, we adopt the equal-weight replacement to simulate the on-site gradation and to measure the average gradient of river bed. With different debris-flow volumes & concentrations and under different maximum grain sizes, we study the retaining effect and the force-endured status with such analytic items as volume concentration reduction rate (Rv), dam-passing rate (Rp), grain deposition rate, vibration meter and displacement meter, etc. For the volume concentration reduction rate, the result of indoor tank test shows that the volume concentration for all cases after passing the dam is reduced to below 03.As the initial volume concentration is 0.45 and 0.55, the volume concentration reduction rate is more than 80%.For the initial volume concentration of 0.35, then the reduction rate is 60.3%.The dam-passing rate will be reduced as increasing the volume concentration, which is less than 40% before the dam reaches the full level. The higher the volume concentration is, then the better the grain deposition rate is. As the volume concentration is 0.65, the grain deposition rate can reach 98.88%. And as the volume concentration is 0.35, the grain deposition rate will be down to 60%. Under the strike of debris-flow again and again, we use the displacement meter and the vibration meter to measure the impact fore of sediments in the auxiliary dam and in front of the dam and the acceleration of sediments in the dam and find that they are significantly reduced. Therefore, through the test, we can find that we can truly make use of the characteristics of a retaining structure to retain & deposit the debris flow. |
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| 口試日期 | 2007-07-07 | 繳交日期 | 2007-09-04 | |