台灣地質環境之構造運動頻繁，因物理或化學作用產生的岩體弱面、斷層以及褶皺等構造極為發達，以工程角度來看，密集的地質構造更直接影響岩石邊坡的穩定性和破壞行為。傳統的單一楔形塊體以兩個弱面及坡面、坡頂構成，破壞時沿兩弱面之交線滑動；然而，依黃鎮臺、夏龍源(1990)之研究結果以及實際走訪台二線83k附近(南雅里)現地調查結果發現，楔形破壞的發生並非僅為兩組不連續面切出之楔形塊體滑動，大多數是由三組不連續面(兩組弱面與層面)所構成的楔形塊體產生破壞，但此一類型的楔形塊體運動方式在前人研究中較少提及。 本研究以人造岩體進行簡化楔形塊體運動及破壞之物理及離心機試驗，以不同的弱面、層面位態以及節理延續性分析楔形塊體的破壞過程，並用數值軟體進行模擬。從研究結果得知：若層面傾向與坡面傾向相反，則楔形塊體運動以翻倒以及滑動破壞為主，且通常為坡趾處的楔形塊體先產生破壞，其塊體崩落率通常較低；若層面傾向與坡面傾向相同，塊體運動模式以沿弱面交線或平面滑動為主，且大多為坡頂或坡面之塊體先產生滑動。此外，在相同層面位態以及節理分布下，兩弱面夾角愈大，其塊體崩落率亦愈大。 ;Taiwan is located at the boundary between the Philippine Sea Plate and Eurasian Plate. Thus, the tectonic plate activity is frequent. Geological structures such as folds, faults, and discontinuities play a critical role in the stability and behaviour of both natural and engineered rock slopes. Traditional wedge block is defined by two discontinuities, slope top and slope face and slide alone the line of intersection. However, compared with Huang, C.T. and Shiah, L.Y., “A case study on the Nan-Ya landslide along the north coast highway” (1990), and the actual investigation of Nanya village. Wedge failure that occurs not only in the rock slope cut by two discontinuities, but most of them is cut by a third set of discontinuities (bedding). In this study we use man made rock material to do physical test、centrifuge test and use 3DEC to simulate the result, in order to know its moving process under different ξ angle、bedding attitude and joint distribution. From the result of this study, we can conclude that: (1) if the bedding is parallel to the line of intersection, block moving process is mostly planer failure. However if the bedding is perpendicular to the line of intersection, block moving process is mostly falling. (2) From the result of different ξ angle but same joint distribution. We found out that the block with ξ=120° has greater falling ratio than the block with ξ=90°.
