Discontinuity Analysis for Rock Engineering

Effective transmissivity of two-dimensional fracture networks

“…This value is within 2% of the exact value 0.947 x 10 m /s that was found by Priest [12] by solving the full set of twenty simultaneous algebraic equations. …”

“…We have used the procedure described above to predict the overall gridblock conductivity of the fracture network that was analyzed by Priest [12] under conditions of saturated flow (Fig. 2).…”

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“…It can be seen that there is a strong correlation between the value of JRC and peak friction angle measured by conducting tilt test, seeing that the coefficient of correlation R 2 are 0.99. Peak friction angles (φ peak ) were measured by using a self-fabricated tilt testing apparatus according to Priest (1993) suggestion (Figure 5). Rock samples that contained upper and lower rock blocks were positioned on the plane and were slowly inclined from the horizontal position until sliding between the planes occurred.…”

Effective transmissivity of two-dimensional fracture networks

“…For a network of saturated fractures, this procedure is analogous to finding the effective conductivity of a network of electrical resistors, and leads to a system of linear algebraic equations [12]. For unsaturated flow, however, the analogy between fluid flow and electrical flow through a linear resistor network breaks down, and the goveming equations become nonlinear.…”

“…2) can be removed because they are clearly not part of the network that will actually conduct fluid. As there are four nodes at which four segments meet (nodes 4,6,10,13), and six nodes at which three segments meet (nodes 5,7,9,12,14), the mean coordination number of the conducting network is z = (4-4 + 6-3)/(4 + 6) = 3.40.…”