裂隙岩體具有空間變異性，其裂隙之方向性對水力傳導係數影響甚大。本文先針對裂隙岩體中水力傳導係數之表徵單元體積（representative elementary volume，REV）進行探討，當岩體體積小於表徵單元體積時，其水力傳導係數（hydraulic conductivity）具有離散性及變異性，試驗及分析結果可能將不具代表性。再利用求得之表徵單元體積進而探討裂隙位態及費雪常數對水力傳導係數的影響。最後，藉由裂隙岩體影響之參數定義連通比之關係。 由於探討岩體裂隙水力傳導係數之研究，往往需要大量試體進行試驗，通常耗時費力且試體幾何變因不易掌握。近年來裂隙岩體數值模擬技術成熟，離散裂隙網絡（discrete fracture network，DFN）是一種廣泛應用於裂隙岩體的建模方法，因此本文利用數值軟體 FracMan 生成離散裂隙網絡，並使用兩種不同計算水力傳導係數之模式(Conventional Oda與 Oda gold)，模擬裂隙岩體的幾何性質及分析取樣岩體的水力傳導係數，以系統性方式進行裂隙幾何的參數研究，包括：岩體模型大小、取樣體積、傾角、傾向、費雪常數、裂隙直徑及裂隙程度等。針對一系列裂隙岩體水力傳導係數的模擬結果，統計裂隙岩體水力傳導係數期望值及變異係數（acceptable coefficient of variance），分別建立其與裂隙幾何關係的量化模式，並彙整影響連通比的參數而量化其關係求得之結果，再將其整合成可代表連通比之量化模式。最後，根據量化模式結果，可決定裂隙岩體的水力傳導係數及連通比，應用於現地之評估及預測裂隙岩體中之流動與傳輸行為，為工程上帶來有效的預防及利益。 ;The property of fractured rock is highly spatial variable, and the directionality of fractures has a great influence on the hydraulic conductivity. This study presents the representative elementary volume (REV) of hydraulic conductivity of fractured rock mass. When the rock sample is smaller than the representative elementary volume (REV), the sampled hydraulic conductivity would be discrete, variable and not representative. Then use the REV to investigate the effect of the fracture orientation and Fisher constant on the hydraulic conductivity. Finally, the relationship of the connectivity is defined by the influence parameters of the fractured rock mass. Due to the research of hydraulic conductivity of fractured rock mass usually needs a large number of specimens to do the test, which is difficult to conduct due to high time-consuming and cost. In recent studies, the discrete fracture network (DFN) was widely used to simulate the fractured rock. FracMan was used to generate DFN in rock mass models and execute the systematical sampling in this study. Conventional Oda and Oda gold were adopted to estimate the hydraulic conductivity of the fractured rock mass. A series parametric study including size of rock mass model, specimen volume, dip angle, dip direction, Fisher constant κ, fracture diameter, and fracture intensity was conducted in this study. The quantized model of mean and coefficient of variance of hydraulic conductivity was established based on the results of parametric study. And consolidated the quantized result of the parameters which influence on the connectivity. Then, integrated these results to represent the quantized model of the connectivity. Finally, according to the results of the quantized model, the hydraulic conductivity and the connectivity of the fractured rock mass can be determined, which is applied to the local assessment and prediction of the flow and transmission behavior in the fractured rock mass. It has effective prevention and benefits to the engineering.
