破裂岩體網路之地下水流動之研究

A Study of Groundwater Flow in Fractured Rocks

李振誥(Cheng-Haw Lee) ； 林碧山(Bih-Shan Lin) ； 吳育生(Yu-Sheng Wu)

《鑛冶：中國鑛冶工程學會會刊》 37卷3期 (1993/09) Pp. 69-77

摘要

本文旨在探討破裂岩體之破裂面幾何參數以及交接性對地下水流量之關係。文中將針對長度、密度等破裂面參數之變化逐一討論。由於地質構造的複雜性，破裂面之參數特性通常以機率分佈函數估計之。然後再以隨機之過程組合以機率分佈函數產生之破裂面，形成一破裂面幾何網路，化表岩體内之破裂面分佈情形，然後代入水力邊界條件，岩石破裂面内之地下水流動模式於焉形成。本文以邊界元素法模擬破碎岩體破裂面内之水流情況，結果顯示：破裂面之數目愈多、破裂面之長度愈長，則平均之交接程度愈高，且相對的平均流量愈大。同時亦顯示若交接程度大於某臨界值時，方有流量產生。

並列摘要

The purpose of this study is to investigate the effect of geometric parameters and connections of fractured rock masses on the flow quantities of groundwater. In this paper, the characters of fracture parameters such as trace length and density are estimated by probability density functions because of the complexity of geology. Then fractures are assembled and formed randomly into a network of fractures within the rock mass so that such a network can be regarded as a representation of the distributed of fractures within the rock mass. Finally taking the hydraulic boundary conditions into the network, a model of groundwater flow is established. In the meantime, Boundary Element Method is applied to simulate groundwater flow in fractured rock masses. The outcomes show that t he more the fractures or the longer the fracture radii or both will result in higher average connectivities and larger average flow quantities. There exists a sharp value of flow if the interconnection of fractures is larger than a percolation threshold.