| 姓名 | 蔣志宏(Chih-Hong Jiang) | 電子郵件信箱 | s9411633@mail.cyut.edu.tw | |
| 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) | 分離元素法應用於土石流行為之研究 | |||
| 論文名稱(英) | Modeling of Debris Flow Using Distinct Element Method | |||
| 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 | 校內外都二年後公開 | |
| 論文語文/頁數 | 中文/110 | |||
| 摘要(中) |
土石流是由砂、礫、巨石、泥等物質與水之混合物受重力作用後所產生的流動體。在台灣，土石流造成重大災害的歷史最早可追朔至1959年在台灣中南部發生的的八七水災，自民國79
年6 月銅門村事件至民國85 年7 月31 日之賀伯風災才喚起國人普遍之重視。且民國88 年9
月21日集集大地震後，大量鬆散的土方堆積在山腳下、山坡上或山谷間，在往後更是大大提高土石流的發生頻率。 本研究計畫主要目的以分離元素法 PFC2D探討為土石流體內顆粒之運動機制，包括顆粒間接觸力、土體位移、土體流動行為模式及粒間微觀參數影響。由實驗室落門試驗及水槽土體啟動模擬結果顯示：以程式模擬於水槽坡度 22度時，坡頂上之土石啟動時之微觀摩擦角約為28度~30度，代回落門試驗之安息角與微觀摩擦角的關係圖，可得到安息角約為56度~60度，但由於地形因子影響關係，所以必須扣除坡度數值 22度，即可以找出啟動土石流之安息角(約等於摩擦角)為34度~38度，與蘇(1998)於此地溪谷堆積物之直接剪力強度試驗之摩擦角 34.7度~ 36.2度相符合。 利用PFC2D模擬土體內部微觀狀態，將可歸納出影響因子之影響程度大小依序為坡度>摩擦角>體積濃度>坡面摩擦角。由本程式分析土石流流動特性其與實際之土石流流動特性相當相近。 |
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| 摘要(英) |
Debris flow is a flow body produced after the action of gravity
by materials, such as mud, sand, gravel, cobble and etc., and
the mixture of water. Major disastrous damage caused by debris
flow can be dated back to 1959 which is known as 8-7 flood
occurred at south central part of Taiwan. However, debris flow
was not paid great attention in Taiwan until the incident at
Tonman Village in June of 1990 and series damages caused by
Typhoon Herb on July 31st, 1996. Especially after 921 Chi-Chi
Earthquake in 1999, a huge number of debris piled up at the foot
of hills, hillsides, or mountain valley, the chance for
occurrence of debris flow will be inevitable in the next 10 to
20 years. The main purpose of this study was to use the discrete element method based program Particle Flow Code (PFC2D) to study the mechanisms of particle movement, including contact forces, displacements, flow pattern, and the strength parameters between particles, of debris flow. The following simulated results based on the particles passing through the falling door tests and the inclined trough tests can be obtained: The particles start moving as the friction angle, , between particles equals to 28 to 30 degrees as the trough slope is 22 degrees. The angle of repose is about 56 to 60 degrees for particles with friction angle of 28 to 30 degrees. The angle of repose is about 34 to 38 degrees if subtract the trough slope. This angle of repose can be treated as the macro friction angle of the debris materials. The obtained results are similar to the friction angles, 34.7 to 36.2 degrees, tested by Su (1998) on valley deposits using direct shear test. The factors that influence the results and occurrence of debris flow can be acquired based on the simulation and analyses using PFC2D. It is found that slope angle is the major reason that controls the incident of debris flow, and then friction angle between particles, volume concentration of the mixture, and friction angle of a slope. The characteristics of the simulated debris flow from this study are very similar to the actual debris flow. |
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| 口試日期 | 2007-07-31 | 繳交日期 | 2007-09-10 | |