Laboratory Simulation of Flow through Single Fractured Granite

Singh, Kunal Kumar; Singh, Devendrá; Ranjith, P.G.

doi:10.1007/s00603-014-0630-9

Cited by 97 publications

(28 citation statements)

References 53 publications

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“…The granites were taken from Linyi city in Shandong Province of China. The granite is a porphyritic monzonite with an average unit weight of about 2.69 g/cm 3 . The uniaxial compressive strength of the rock is about 97.54 MPa, and its permeability is in the order of magnitude of 10 −19 m 2 .…”

Section: Rock Fracture Specimen Preparationmentioning

confidence: 99%

“…Rock fracture networks constitute the main pathways of fluid flow and solute migration in deep underground projects, and during the past several decades, substantial efforts have been devoted to the estimation of fluid flow behavior and transmissivity of fractures in many geoengineering and geosciences such as underground tunneling [1][2][3], CO 2 sequestration [4,5], geothermal energy extraction [6][7][8], and hazardous wastes isolation [9][10][11]. The fluid flow in rock fractures is commonly assumed to follow the cubic law, in which the flow rate is linearly proportional to the pressure gradient [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

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Experimental Study on Stress-Dependent Nonlinear Flow Behavior and Normalized Transmissivity of Real Rock Fracture Networks

et al. 2018

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The mechanism and quantitative descriptions of nonlinear fluid flow through rock fractures are difficult issues of high concern in underground engineering fields. In order to study the effects of fracture geometry and loading conditions on nonlinear flow properties and normalized transmissivity through fracture networks, stress-dependent fluid flow tests were conducted on real rock fracture networks with different number of intersections (1, 4, 7, and 12) and subjected to various applied boundary loads (7, 14, 21, 28, and 35 kN). For all cases, the inlet hydraulic pressures ranged from 0 to 0.6 MPa. The test results show that Forchheimer's law provides an excellent description of the nonlinear fluid flow in fracture networks. The linear coefficient and nonlinear coefficient in Forchheimer's law = + 2 generally decrease with the number of intersections but increase with the boundary load. The relationships between and can be well fitted with a power function. A nonlinear effect factor = 2 /( + 2 ) was used to quantitatively characterize the nonlinear behaviors of fluid flow through fracture networks. By defining a critical value of = 10%, the critical hydraulic gradient was calculated. The critical hydraulic gradient decreases with the number of intersections due to richer flowing paths but increases with the boundary load due to fracture closure. The transmissivity of fracture networks decreases with the hydraulic gradient, and the variation process can be estimated using an exponential function. A mathematical expression / 0 = 1 − exp(− −0.45 ) for decreased normalized transmissivity / 0 against the hydraulic gradient was established. When the hydraulic gradient is small, / 0 holds a constant value of 1.0. With increasing hydraulic gradient, the reduction rate of / 0 first increases and then decreases. The equivalent permeability of fracture networks decreases with the applied boundary load, and permeability changes at low load levels are more sensitive.

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Section: Rock Fracture Specimen Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental Study on Stress-Dependent Nonlinear Flow Behavior and Normalized Transmissivity of Real Rock Fracture Networks

et al. 2018

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“…Singh et al [17], [18] observed that non-linear behaviour exists between the discharge (Q) and effective fluid pressure (σeff.) and there is a rapid decrease in Q till 10 MPa beyond which the fracture aperture closes very quickly and flow through fracture ceases (Fig.…”

Section: Effect Of Normal Load and Fluid Pressure On Jointsmentioning

confidence: 99%

Landslide in fractured and stratified rocks - A case from Aizawl, Mizoram, India

Singh¹,

Das²,

Singh³

et al. 2016

Proceedings of the Conference on Recent Advances in Rock Engineering (RARE 2016)

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Abstract-Stratified rock cut slopes for e.g. shale-sandstonesiltstone layers are a common occurrence in some part of the Himalayas. These rocks are highly jointed and bears low strength to sustain significant engineering load. A similar geological condition exists in the north eastern Himalayas (Aizawl, Mizoram) where such rocks have been exposed along cut slopes. The area receives heavy rainfall during the monsoonal months and the presence of clay make these rocks highly susceptible to intense weathering. Further, the presence of widely spaced orthogonal joints along with persistent bedding parallel joints allow water to percolate deeper into the formation. Accumulation of water with time in the pore spaces of rocks and in the interface between the strata leads to opening of the joints and considerable reduction of shear strength. Despite of incompetency of these rocks, large number of transportation lines and settlements are being built to meet the demand of increasing population in India. Unscientific design and inadequate use of geological and geotechnical information during construction allow these rocks to deteriorate and degrade in strength before the engineering life of the structure eventually leading to slope failure and mass destruction. Therefore, the present study mainly deals with the influence of long term weathering on the strength degradation of the exposed rocks by a series of experimental observations followed by numerical simulation of cut slope using distinct element method. The purpose is to gauge into the health of the slope and the processes which leads to slope failure under normal gravity and hydro-mechanical loading conditions. The result of this analysis is very promising which discusses several important issues like effective loading direction, maximum allowed load on the crest of the slope, zones of maximum displacement and maximum flow rate observed along the slope face, mode and depth of failure plane. Understanding these challenges will assist the planners to design appropriate support systems for long term safety and sustainability of the structures and avoid future slope failure.

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“…In many cases, artificial joint specimens are prepared, in order to carry out mechanical and/or hydraulic experiments. The joint specimens are often created mechanically by using a splitter or a V block, which applies a concentrated load at the center of rock block or cylinder similar with Brazilian jaws [15,16]. Tensile stress generated along the loading axis bisects the rock into two halves.…”

Section: Introductionmentioning

confidence: 99%

“…Although it is a simple method to create a joint specimen, it requires excessive efforts if a specific joint roughness is desired. Therefore some experimental works have derived results from limited test conditions in terms of the joint roughness [3,16]. The reproducibility of this approach is hardly guaranteed so that casting method, which uses cement mortar or epoxy, is adopted as an alternative to make multiple joint specimens that have similar levels of roughness [17,18].…”

Section: Introductionmentioning

confidence: 99%

Development of a New Method for the Quantitative Generation of an Artificial Joint Specimen with Specific Geometric Properties

et al. 2019

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A rock joint is a planar discontinuity that has significant influence on the mechanical and hydraulic characteristics of rock mass. Laboratory experiments are often conducted on a joint to investigate and provide fundamental information for rock mass analysis. Although joint roughness and mechanical aperture exert great effects on the experimental results, controlling them in quantitative manner is quite complicated and consumptive in terms of specimen preparation. A new and simple method for the quantitative generation of the joint specimen was proposed in this study. Based on random midpoint displacement method, a joint specimen with a void space inside was generated. Parametric studies for the roughness and mechanical aperture were carried out, and as a result, the two joint properties could be controlled by manipulating input parameters of random midpoint displacement method. In order to validate the proposed method, two joint specimens, which had different levels of roughness and aperture, were generated and printed. Surface coordinates of the specimens were obtained by a 3D laser scanner, and calculated to make a comparison between the target values and the estimated values. Results showed that the method was capable of generating joint specimens with satisfactory precision.

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Laboratory Simulation of Flow through Single Fractured Granite

Cited by 97 publications

References 53 publications

Experimental Study on Stress-Dependent Nonlinear Flow Behavior and Normalized Transmissivity of Real Rock Fracture Networks

Experimental Study on Stress-Dependent Nonlinear Flow Behavior and Normalized Transmissivity of Real Rock Fracture Networks

Landslide in fractured and stratified rocks - A case from Aizawl, Mizoram, India

Development of a New Method for the Quantitative Generation of an Artificial Joint Specimen with Specific Geometric Properties

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