以模型試驗探討加勁泥岩邊坡侵蝕之研究

泥岩在台灣的分布為西南部泥岩地區、花東泥岩地區、以及恆春半島泥岩地區，以西南部泥岩的規模最大，潛在的面積廣達一千多平方公里，其厚度在數千公尺以上。泥岩的成岩時間比較短，本身材料的強度並不高，在岩石的分類上屬於軟岩類，其工程性質介於土壤與岩石之間，在乾燥狀態下堅硬如岩石，遇水之後軟爛如泥。泥岩遇水後易產生回脹、崩解的現象，因此其抵禦外在環境的侵蝕能力上比較差，因此常產生工程問題及邊坡破壞引致之災害。本研究透過對未保護泥岩邊坡、柔性回包式加勁泥岩邊坡、纖維加勁泥岩邊坡三種型式之邊坡進行模擬降雨試驗，並且令邊坡經歷自然乾裂至少24小時後再次進行降雨實驗，透過此循環實驗探討其邊坡保護效果及對於泥岩邊坡抗侵蝕性的成效。研究顯示未保護之泥岩邊坡之侵蝕行為與泥岩邊坡發育過程；柔性回包式加勁泥岩邊坡於研究中顯示於循環降雨實驗初期即具有良好的邊坡保護、抗侵蝕效果，且於循環實驗中維持低且平穩之侵蝕量；纖維加勁泥岩邊坡的研究結果顯示於前期具有較高侵蝕量，但侵蝕量卻表現出隨著時間遞減的特性，邊坡的抗沖蝕能力亦隨時間增加。

關鍵字

泥岩；抗沖蝕；回包式加勁；纖維加勁；降雨試驗；邊坡模型

並列摘要

Mudstone is distributed in the southwest, the Huadong, and the Hengchun Peninsula mudstone area. The southwestern mudstone has the largest scale, with a potential area of more than 1,000 square kilometers, and its thickness is more than thousands of meters. The diagenesis time of mudstone is relatively short, and the strength of its own material is not high. It belongs to soft rock in the classification of rocks, and the engineering properties are between soil and rock. It is hard as rock in a dry state, and soft as mud when it meets water. Mudstone is prone to swell and collapse after running into water, so its ability to resist the erosion of the external environment is relatively poor, so engineering problems and disasters caused by slope damage often occur. This study conducted simulated rainfall tests on three types of slopes: unprotected mudstone slopes, flexible wrapped-around geosynthetic reinforced mudstone slopes, and fiber-reinforced mudstone slopes. The slopes were subjected to natural drying for at least 24 hours and then subjected to rainfall experiments. This cyclic experiment explores its slope protection effect and its effect on mudstone slope erosion resistance. The study has shown the erosion behavior and development process of unprotected mudstone slopes; the flexible wrapped-around geosynthetic reinforced mudstone slopes have been shown in the research to have good slope protection and anti-erosion effects at the beginning of the cyclic rainfall experiment. And the erosion keeps low and steady during the cyclic experiment; the research results of fiber-reinforced mudstone slopes show that there is a high amount of erosion in the early cyclic rainfall experiment, but it shows the characteristics of decreasing with time, and the erosion resistance of the slope increase as well.