On the applicability of self-affinity concept in scale of three-dimensional rock joints

Yang, Zon-Yee; Taghichian, Ali; Huang, G. J.

doi:10.1016/j.ijrmms.2011.06.010

Cited by 27 publications

(6 citation statements)

References 38 publications

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“…For this reason, % Std Dev L values were used for establishing this 3-point index. Ranked from lowest to highest are Sites 17,7,5,2,4,16,11,9,13,12,8,15,1,18,14,6,10, and 3, with the median situated between Sites 12 and 13 (13.88%). This constitutes a medium level of surface roughness according to the SRI, where Std Dev L values between 0% and 10% represent a low surface roughness; 11% -20% is medium; and 21%+ is high ( Table 2).…”

Section: Resultsmentioning

confidence: 99%

“…Sometimes it is not possible to sample directly in the field and molds/casts are used for later analysis. For instance, Yang and colleagues [9] made a mold of a mica-schist joint and used a laser scanner to produce a digital image of it. The laser profilometer employed was a noncontact optical instrument used in order to obtain vertical and horizontal profile numbers.…”

Section: Introductionmentioning

confidence: 99%

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Measuring Surface Roughness through the Use of Digital Photography and Image Processing

Thornbush

2014

IJG

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This paper aims to provide a quantitative method that employs image processing in the assessment of surface roughness based on digital photograph field surveys, as in previous studies employing the outdoor integrated digital photography and image processing (O-IDIP) method. Digital photographs were taken on two different days under contrasting outdoor lighting conditions (overcast versus clear sky). Images were captured mounted on a tripod close up to the surface of a 380-year-old wall located at the University of Oxford Botanic Garden in the City of Oxford, UK. Sampling points were established at regular intervals along the border wall and encompassed sections facing west, north, and east, respectively along the survey. Two photographs were taken with a digital camera at each sampling point, one containing a color chart used to calibrate outdoor lighting conditions across images, which was excluded from the other photographic pair. Histogram-based quantification was performed based on images converted to Lab Color mode. The 10-step calibration procedure presented in this paper required more adjustments of contrast. However, more adjustments were not required under a clear sky. Std Dev L measurements were used to establish categories in a simple 3-point roughness index, namely the surface roughness index (SRI). The results denote that pitting did not affect surface roughness measurements. The study shows that it is possible to use Std Dev L measurements to quantify surface roughness on a comparative basis.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Measuring Surface Roughness through the Use of Digital Photography and Image Processing

Thornbush

2014

IJG

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“…This depends mainly on the weathering of the ruptures and the texture and structure of the rock. The strength and deformation behavior of fractures also depends on their surface roughness (Maerz et al, 1990;Kulatilake et al, 1995;Kabeya and Legge, 1997;Xia et al, 2003;Yang et al, 2011), as fracture surfaces are not completely simply planar and smooth. The mechanical properties of fractures are, among others, influenced by the shape, size, and number of individual contacts between the particular surfaces (Gentier et al, 1999;Egger, 2002, 2000;Cottrel et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…Previous research has dealt primarily with the roughness and overall appearance of the rupture surface as a basic parameter for artificial models with relatively accurate castings of ruptures usually on gypsum (Yang et al, 2001) or a mixture of gypsum and sand (Kulatilake et al, 1995(Kulatilake et al, , 1999. Other variables in the experimental models, such as the effect of water, the rupture range, and the degree of weathering, were almost neglected (Kulatilake et al, 1995(Kulatilake et al, , 1998(Kulatilake et al, , 1999Yang et al, 2001Yang et al, , 2011Wang et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Experimental study of rock ruptures shear strength anisotropy

Proisl¹

2022

Acta Geodynamica Et Geomaterialia

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Joints significantly reduce rock cohesion compared to unfractured rock, but the question is what effect the possible anisotropy of the shear strength of different types of rupture has on possible subsequent failure. Both natural samples of granodiorite with natural joints and fault surfaces and gypsum models have been tested on the Matest A129 Rock shear box apparatus. The shear strength of preexisting ruptures was measured under a fixed normal stress component. The anisotropy of the shear strength of the joints and fault surfaces reached more than 60 % of maximum strength, which is a very important value for solving structural loads. The shear strength was analyzed with polar plots. The pattern of the real joints typically showed a teardrop shape with one peak of strength in a certain direction and a minimum in the opposite direction. On the contrary, striated fault surfaces are characterized by two axial directions of minimal shear strength, i.e., longitudinal and transverse, and by two axial oblique directions with maximal shear strength, so the strength distribution in the polar graph has a four-cornered shape. The study showed that the anisotropy of the shear strength of various types of ruptures is their important feature.

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“…Under cyclic loading conditions, the fatigue characteristics of the jointed rock were analysed for different joint geometries [16]. Through shear testing, the influence of the number of cycles on the shear strength of jointed rock was studied under cyclic loading [17][18][19], and the type of rock and joint roughness and size have a certain influence on the shear strength of the rock mass [20][21][22]. The deformation and strength characteristics of rock with different forms of joints were obtained by tensile tests and uniaxial compression tests [23,24].…”

Section: Introductionmentioning

confidence: 99%

Fracture Failure Characteristics of Jointed Sandstone under Uniaxial Compression

Liu

2020

Geofluids

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Jointed rocks are ubiquitous in the complex environments (coupled heat and moisture conditions) encountered in deep underground mining. To investigate the influence of the joint locations on the strength, deformation, and fracture failure characteristics of the jointed sandstone, uniaxial compression tests were carried out for sandstone specimens in a natural moisture state and with a preexisting joint in different locations. The entire test process was recorded by a dynamic strain acquisition system and digital speckle observation equipment. The results show that the peak strength weakening of the jointed sandstone was different with different joint positions. The residual strength and lateral deformation of the jointed sandstone were affected by the location of the joint. The joint locations dominated the evolution of the fractures in the sandstone and influenced the failure mode. The fracture evolution in sandstone with a joint in the middle was characterized by the closure of the fractures away from the starting position and was finally destroyed by the combination of shearing and splitting. The evolution of fractures in the sandstone with a joint at the bottom was stopped on the other side, which was eventually sheared across the joint. Besides, based on fractal theory, the fracture distribution on the specimen surface was analysed at certain points (first appearance of fracture, peak point) and the final destruction state during the fracture evolution. The fractal dimension was obtained, which further characterizes the fracture evolution and failure of sandstone with a joint at different locations.

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On the applicability of self-affinity concept in scale of three-dimensional rock joints

Cited by 27 publications

References 38 publications

Measuring Surface Roughness through the Use of Digital Photography and Image Processing

Measuring Surface Roughness through the Use of Digital Photography and Image Processing

Experimental study of rock ruptures shear strength anisotropy

Fracture Failure Characteristics of Jointed Sandstone under Uniaxial Compression

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