Estimation of the REV Size and Equivalent Permeability Coefficient of Fractured Rock Masses with an Emphasis on Comparing the Radial and Unidirectional Flow Configurations

2018 ◽  
Vol 51 (5) ◽  
pp. 1457-1471 ◽  
Author(s):  
Zhechao Wang ◽  
Wei Li ◽  
Liping Bi ◽  
Liping Qiao ◽  
Richeng Liu ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Fractured Rock ◽  
Rock Masses ◽  
Equivalent Permeability ◽  
Unidirectional Flow ◽  
Flow Configurations ◽  
Fractured Rock Masses

scholarly journals Correlations between Geometric Properties and Permeability of 2D Fracture Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiaolin Wang ◽  
Liyuan Yu ◽  
Hanqing Yang
Keyword(s):  
Fractured Rock ◽  
Rock Fracture ◽  
Fractal Dimensions ◽  
Fracture Network ◽  
Network Structures ◽  
Rock Masses ◽  
Fracture Networks ◽  
Geometric Properties ◽  
Equivalent Permeability ◽  
Fractured Rock Masses

The equivalent permeability of fractured rock masses plays an important role in understanding the fluid flow and solute transport properties in underground engineering, yet the effective predictive models have not been proposed. This study established mathematical expressions to link permeability of 2D fracture networks to the geometric properties of fractured rock masses, including number density of fracture lines, total length of fractures per square meter, and fractal dimensions of fracture network structures and intersections. The results show that the equivalent permeability has power law relationships with the geometric properties of fracture networks. The fractal dimensions that can be easily obtained from an engineering site can be used to predict the permeability of a rock fracture network. When the fractal dimensions of fracture network structures and intersections exceed the critical values, the effect of randomness of fracture locations is negligible. The equivalent permeability of a fracture network increases with the increment of fracture density and/or fractal dimensions proportionally.

scholarly journals Investigation of the Models of Flow through Fractured Rock Masses Based on Borehole Data

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Long Tan ◽  
Wei Xiang ◽  
Jin Luo ◽  
Qingbing Liu ◽  
Xu Zuo
Keyword(s):  
Permeability Coefficient ◽  
Flow Model ◽  
Fractured Rock ◽  
Confining Pressure ◽  
Seepage Flow ◽  
Rock Masses ◽  
Borehole Data ◽  
Proposed Model ◽  
Flow Through ◽  
Fractured Rock Masses

When only limited borehole data are available, making optimum use of the existing data is crucial for performing a preliminary assessment of the investigated site. In this paper, the relationships between the borehole data and the permeability coefficient were first analyzed. These relationships were then used to establish a model for estimating the permeability coefficient of rock mass that takes into account the influence from the confining pressure on the seepage flow. The proposed model can reduce the number of hydraulic tests which are time consuming and very costly and allow the determination of change in the permeability coefficient throughout the borehole. The flow model could assist in providing important references for selecting an appropriate permeability coefficient in hydrogeological simulation and in evaluating the condition of large cracks developed in boreholes. In general, the seepage flow model developed in this study will contribute to the design practice of a tunnel project constructed in fractured rock masses.

scholarly journals A New Approach to Permeability Inversion of Fractured Rock Masses and Its Engineering Application

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 734
Author(s):  
Lei Gan ◽  
Guanyun Chen ◽  
Zhenzhong Shen
Keyword(s):  
Groundwater Level ◽  
Permeability Coefficient ◽  
Mean Squared Error ◽  
Fractured Rock ◽  
Coefficient Of Determination ◽  
Left Bank ◽  
Rock Masses ◽  
Reservoir Area ◽  
Fractured Rock Masses ◽  
Tolerance Method

This paper presents a new seepage inversion technique to predict the permeability coefficient of the rock mass with developed fracture or fault. With the measured data of flow and water head of boreholes, the permeability coefficient of the rock masses near the boreholes are obtained by inverse calculation on the basis of unsteady seepage tests. Then, a flexible tolerance method is proposed to invert the permeability coefficient of rock masses in different zones of the reservoir area. This comprehensive inversion analysis method is applied in one actual project of the water supply reservoir. The equivalent permeability coefficient of the rock masses in the range of 0 m to 16.0 m below the road surface near the dam axis on the left bank of the mountain is 1.12 × 10−3 cm/s. The root mean squared error and coefficient of determination of the measured and calculated values are 1.33 × 10−4 m3/s and 0.9976 m3/s, respectively. The rock masses in the reservoir site area have high permeability. The groundwater level in the junction area and the mountains on both sides of Shangmo reservoir is low, and the hydraulic gradient is small. The maximum error between the calculated value of the groundwater level and the measured values is −0.41 m, and the relative error is −4.36%. The recommended anti-seepage scheme can effectively solve the problem of large leakage in the reservoir area. The results show that the innovative approach is appropriate for the seepage analysis of the field with the fractured rock masses and more meaningful from an engineering point of view.

scholarly journals Elastic properties of fractured rock masses

2018 ◽  
Author(s):  
Philippe Davy ◽  
Caroline Darcel ◽  
Romain Le Goc ◽  
Diego Mas Ivars
Keyword(s):  
Elastic Properties ◽  
Fractured Rock ◽  
Rock Masses ◽  
Fractured Rock Masses
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