A MODIFIED EQUIVALENT PERMEABILITY MODEL OF FRACTURE ELEMENT AND ITS VERIFICATION
WANG Zhen1，2，RUTQVIST Jonny2，ZUO Jianping2，3，DAI Ying1
(1. School of Aerospace Engineering and Applied Mechanics，Tongji University，Shanghai 200092，China；2. Earth Science Division，Lawrence Berkeley National Laboratory(LBNL)，Berkeley，CA94720，USA；3. State Key Laboratory of Coal Resources and Safe Mining，China University of Mining and Technology，Beijing 100083，China)
Abstract：A conceptual model of fracture element is presented that characterizes the discrete fracture network with fracture elements. We calculate the equivalent permeability of fracture element based on the principle of equivalence of flux between a single fracture and a square element. But the“stair-case”fracture elements increase the length of flow path，and result in a decrease of flux with an unaltered hydraulic pressure difference. To solve this problem，we modify the fracture elementary permeability through considering the ratio of length of flow path to fracture length；and for the complex fracture network，the isolated fractures，dead-end parts of fractures and the isolated fracture clusters are deleted to build up a connected fracture configuration. To verify the modified equivalent permeability model we perform fluid flow simulations on a series of single fracture，intersecting fractures and complex fracture network. The calculated total flow rate and flux distribution along the downstream outlet are consistent with the analytical results and discrete fracture network model results. The modified equivalent permeability model can also characterize the heterogeneity and anisotropy of fluid flow in fractured rock mass.
王 臻1，2，RUTQVIST Jonny2，左建平2，3，戴 瑛1 . 裂隙单元修正等效渗透率模型及其验证[J]. 岩石力学与工程学报, 2013, 32(4): 728-733.
WANG Zhen1，2，RUTQVIST Jonny2，ZUO Jianping2，3，DAI Ying1. A MODIFIED EQUIVALENT PERMEABILITY MODEL OF FRACTURE ELEMENT AND ITS VERIFICATION. , 2013, 32(4): 728-733.
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2013, Vol. 32 
