Hydro-Mechanical Coupled Analysis of the Variable Permeability Coefficient of Fractured Rock Mass

Based on the fluid-solid coupling theory, we describe the fractured rock mass as a continuous porous medium and consider the rock mass permeability coefficient a function of the stress and strain. By using the multi-physics coupling analysis software COMSOL, we achieved the dynamic change of permeability coefficient, and found that serious damage due to micro cracking occurred in the excavated damage zone of rock mass due to the yield and failure of rock mass. Corrodingly, permeability will remarkably increase, which is basically consistent with the experimental results. The simulations indicated the "indirect coupling" effect of seepage and stress. Therefore, the coupled analysis of the seepage and stress in fractured rock masses is important for the practical rock mechanics and rock engineering.

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Analysis of Coupled Three-Dimensional Seepage and Temperature Fields in Fracture Network of Rock Mass

International Journal of Computational Methods ◽

10.1142/s0219876219500051 ◽

2019 ◽

Vol 17 (04) ◽

pp. 1950005 ◽

Cited By ~ 1

Author(s):

Zengguang Xu ◽

Yang Liu ◽

Yaping Wang ◽

Junrui Chai ◽

Yanlong Li

Keyword(s):

Rock Mass ◽

Coupling Effect ◽

Fractured Rock ◽

Seepage Flow ◽

Fracture Network ◽

Temperature Fields ◽

Fractured Rock Mass ◽

Flow Temperature ◽

Geothermal Resources ◽

Mass Temperature

The coupling effect of seepage and temperature fields in fractured rock mass is a hot topic in the area of water conservancy, nuclear waste disposal and geothermal resources development. A coupling mathematical model of the seepage, flow temperature and rock mass temperature fields in the fracture network of rock mass is established based on the seepage and temperature interaction. A calculation program is developed and applied to calculate the seepage and temperature fields of the dam foundation of a water conservancy project. The interaction mechanism of the seepage, flow temperature and rock mass temperature fields is analyzed in this paper. Results show that the seepage field largely influences the temperature field, which can provide several suggestions for the deep underground disposal of nuclear waste, geothermal resources development and fractured rock mass in dam foundations. Considering the coupling effect of the seepage, flow temperature and rock mass temperature fields by the fracture network method is necessary.

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Determining the REV for Fracture Rock Mass Based on Seepage Theory

Geofluids ◽

10.1155/2017/4129240 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Lili Zhang ◽

Lu Xia ◽

Qingchun Yu

Keyword(s):

Rock Mass ◽

Fractured Rock ◽

Engineering Application ◽

Existence Condition ◽

Analysis Tool ◽

Fractured Rock Mass ◽

Rock Classification ◽

Fracture Spacing ◽

Fractured Rock Masses

Seepage problems of the fractured rock mass have always been a heated topic within hydrogeology and engineering geology. The equivalent porous medium model method is the main method in the study of the seepage of the fractured rock mass and its engineering application. The key to the method is to determine a representative elementary volume (REV). The FractureToKarst software, that is, discrete element software, is a main analysis tool in this paper and developed by a number of authors. According to the standard of rock classification established by ISRM, this paper aims to discuss the existence and the size of REV of fractured rock masses with medium tractility and provide a general method to determine the existence of REV. It can be gleaned from the study that the existence condition of fractured rock mass with medium tractility features average fracture spacing smaller than 0.6 m. If average fracture spacing is larger than 0.6 m, there is no existence of REV. The rationality of the model is verified by a case study. The present research provides a method for the simulation of seepage field in fissured rocks.

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A Fractal Model for Characterizing Hydraulic Properties of Fractured Rock Mass under Mining Influence

Geofluids ◽

10.1155/2019/8391803 ◽

2019 ◽

Vol 2019 ◽

pp. 1-17 ◽

Cited By ~ 1

Author(s):

Xiaoli Liu ◽

Tao Liang ◽

Sijing Wang ◽

Kumar Nawnit

Keyword(s):

Fractal Dimension ◽

Rock Mass ◽

Permeability Coefficient ◽

Fractured Rock ◽

Length Distribution ◽

Fracture Network ◽

Fractal Model ◽

Physical Model Test ◽

Fractured Rock Mass ◽

Fractal Characteristics

In this paper, two basic assumptions are introduced: (1) The number and length distribution of fractures in fractured rock mass are in accordance with the fractal law. (2) Fluid seepage in the fractures satisfies the cubic law. Based on these two assumptions, the fractal model of parallel seepage and radial seepage in fractured rock mass is established, and the seepage tensor of fracture network which reflects the geometric characteristics and fractal characteristics of fracture network under two kinds of seepage is derived. The influence of fracture geometry and fractal characteristics on permeability is analyzed, and the validity and accuracy of the model are verified by comparing the calculated results of the theoretical model and physical model test. The results show that the permeability coefficient K of fracture network is a function of the geometric (maximum crack length Lmax, fractured horizontal projection length L0, diameter calculation section porosity Φ, fracture strike α, and fracture angle θ) and fractal characteristics (fracture network fractal dimension Df and seepage flow fractal dimension DT). With the increase of fractal dimension Df, the permeability coefficient increases. With the increase of DT, the permeability coefficient decreases rapidly. And the larger the Df (Df>1.5), the greater the change of permeability coefficient K with DT.

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Seepage Field-Strain Field Coupling Analysis for Rock Masses of Coal Seam Floor during Mining Based on COMSOL

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1010-1012.1467 ◽

2014 ◽

Vol 1010-1012 ◽

pp. 1467-1470 ◽

Cited By ~ 2

Author(s):

Yun Jie Zhang ◽

Cheng Fan

Keyword(s):

Rock Mass ◽

Permeability Coefficient ◽

Fractured Rock ◽

Dynamic Change ◽

Stress And Strain ◽

Seepage Field ◽

Coupling Analysis ◽

Field Coupling ◽

Limestone Aquifers ◽

Rock Mass Permeability

Based on the fluid-solid coupling theory, The fractured rock mass was described as a continuous porous medium, and consider the rock mass permeability coefficient has a relationship with the stress and strain. The dynamic change of permeability coefficient was achieved using the multi-physics coupling analysis software COMSOL, and found that the stress and strain of surrounding rocks changes a lot due to mining. The maximum stress and strain in the mudstone area reaches 2-3 times of the original one, which happened at the immediate roof of mined-out area. According to the analysis of seepage field, mining does not destroy water resistance of floor aquifer. Mining fissures do not connect limestone aquifers, and water in the limestone is less likely to flow into stop to cause damage.

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Seepage–stress coupled analysis on anisotropic characteristics of the fractured rock mass around roadway

Tunnelling and Underground Space Technology ◽

10.1016/j.tust.2014.03.005 ◽

2014 ◽

Vol 43 ◽

pp. 11-19 ◽

Cited By ~ 44

Author(s):

T.H. Yang ◽

P. Jia ◽

W.H. Shi ◽

P.T. Wang ◽

H.L. Liu ◽

...

Keyword(s):

Rock Mass ◽

Fractured Rock ◽

Coupled Analysis ◽

Fractured Rock Mass

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Experimental Study of a New Concrete Admixture and Its Function in Filling and Reinforcing Granite Fissures

Geofluids ◽

10.1155/2021/8587258 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Songnan Ru ◽

Zuozhou Li ◽

Handong Liu ◽

Huaichang Yu ◽

Chunlei Wei ◽

...

Keyword(s):

Rock Mass ◽

Water Retention ◽

Fractured Rock ◽

Triaxial Compression ◽

Tensile Tests ◽

Fractured Rock Mass ◽

Failure Characteristics ◽

Basic Performance ◽

Confining Pressures ◽

Fractured Rock Masses

A concrete admixture with water retention and superhydrophobic properties was developed according to the high tensile strength, fissure resistance, and antiseepage requirements of concrete linings. Capillary water absorption, early-age anticracking, cube compressive strength, and splitting tensile tests were employed to study the effects of the new concrete admixture on the basic performance of concrete. On this basis, a triaxial compression test was conducted on granite fissures filled with concrete containing the admixture; the stress-strain and failure characteristics under different admixture dosages, confining pressures, and fracture widths were analyzed, and the reinforcement effect of the concrete with the admixture on the fractured rock mass was studied. The results show that the admixture can effectively improve the ability of concrete to resist water and fissures, and the concrete with the admixture significantly reinforced the fractured rock mass. Therefore, it can be widely applied in filling and reinforcing fractured rock masses.

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