scholarly journals Regularization of Isolated Codimension-2 Discontinuity Sets

2021 ◽  
Vol 20 (4) ◽  
pp. 2630-2670
Author(s):  
Noah Cheesman ◽  
Kristian Uldall Kristiansen ◽  
S. J. Hogan
Keyword(s):  
Discontinuity Sets

2D quantitative analysis of fractures from high-resolution photos for the geomechanical characterization of rock masses

2021 ◽  
Author(s):  
Emmanuel Wyser ◽  
Lidia Loiotine ◽  
Charlotte Wolff ◽  
Gioacchino Francesco Andriani ◽  
Michel Jaboyedoff ◽  
...  
Keyword(s):  
High Resolution ◽  
Point Clouds ◽  
Mitigation Measures ◽  
Future Perspective ◽  
Rock Masses ◽  
Sampling Errors ◽  
Discontinuity Sets ◽  
Adverse Weather ◽  
Geomechanical Characterization

<p>The identification of discontinuity sets and their properties is among the key factors for the geomechanical characterization of rock masses, which is fundamental for performing stability analyses, and for planning prevention and mitigation measures as well.<br>In practice, discontinuity data are collected throughout difficult and time-consuming field surveys, especially when dealing with areas of wide extension, difficult accessibility, covered by dense vegetation, or with adverse weather conditions. Consequently, even experienced operators may introduce sampling errors or misinterpretations, leading to biased geomechanical models for the investigated rock mass.<br>In the last decades, new remote techniques such as photogrammetry,<em> Light Detection and Ranging</em> (LiDAR), <em>Unmanned Aerial Vehicle</em> (UAV) and <em>InfraRed Thermography </em>(IRT) have been introduced to overcome the limits of conventional surveys. We propose here a new tool for extracting information on the fracture pattern in rock masses, based on <em>remote sensing </em>methods, with particular reference to the analysis of high-resolution georeferenced photos. The first step consists in applying the <em>Structure from Motion</em> (SfM) technique on photos acquired by means of digital cameras and UAV techniques. Once aligned and georeferenced, the orthophotos are exported in a GIS software, to draw the fracture traces at an appropriate scale. We developed a MATLAB routine to extract information on the geostructural setting of rock masses by performing a quantitative 2D analysis of the fracture traces, based on formulas reported in the literature. The code was written by testing few experimental and simple traces and was successively validated on an orthophoto from a real case study.<br>Currently, the script plots the fracture traces as polylines and calculates their orientation (strike) and length. Subsequently, it detects the main discontinuity sets by fitting an experimental composite Gaussian curve on histograms showing the number of discontinuities according to their orientation, and splitting the curve in simpler Gaussian curves, with peaks corresponding to the main discontinuity sets.<br>Then, for each set, a linear scanline intersecting the highest number of traces is plotted, and the apparent and real spacing are calculated. In a second step, a grid of circular scanlines covering the whole area where the traces are located is plotted, and the mean trace intensity, trace density and trace length estimators are calculated.<br>It is expected to test the presented tools on other case studies, in order to optimize them and calculate additional metrics, such as persistence and block sizes, useful to the geomechanical characterization of rock masses.<br>As a future perspective, a similar approach could be investigated for 3D analyses from point clouds.</p>

scholarly journals Assessing fracture occurrence using "weighted fracturing density": a step towards estimating rock instability hazard

2004 ◽  
Vol 4 (1) ◽  
pp. 83-93 ◽  
Author(s):  
M. Jaboyedoff ◽  
F. Baillifard ◽  
F. Philippossian ◽  
J.-D. Rouiller
Keyword(s):  
Fracture Density ◽  
Probability Of Occurrence ◽  
Major Class ◽  
Line Parallel ◽  
Digital Elevation ◽  
Discontinuity Sets ◽  
The Mean ◽  
Slope Instabilities ◽  
Elevation Model ◽  
Effective Use

Abstract. Based on the assumption that major class of rock instabilities are created by discontinuities, a method is proposed to estimate the fracture density by means of a digital elevation model (DEM). By using the mean orientation, the mean spacing and the mean trace length of discontinuity sets potentially involved in slope instabilities and a DEM, it is possible to calculate the mean number of discontinuities of a given set per cell of the DEM. This would allow for an estimation of the probability of the presence of at least one discontinuity in a given area or simply in a topographic cell of the DEM. This analysis highlights sites potentially affected by rockslides within a region. Depending on the available data, the mean number can be calculated either by area, or along a line parallel to the mean apparent spacing. The effective use of the probability of occurrence is dependent on the size of the discontinuities because short and closely spaced discontinuities will have a 100% probability of occurrence in each favorable location. The a posteriori prediction of a recent rockslide is discussed as an example.

Fracturing within anticlines and its kinematic control on slope stability

2002 ◽  
Vol 8 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Thomas C. Badger
Keyword(s):  
Slope Stability ◽  
Ground Water ◽  
Slope Failure ◽  
Mode I ◽  
Mode Ii ◽  
Shear Stresses ◽  
Fold Axis ◽  
Slope Failures ◽  
Kinematic Control ◽  
Discontinuity Sets

Abstract Anticlinal folding generates both bedding-parallel shear stresses and tensional stresses radial to the fold axis. These stresses typically produce two sets of discontinuities. Discontinuity set S 1 forms coincident with bedding (S 0 ) as a mode II fracture, and discontinuity set S 2 forms perpendicular to bedding and strikes parallel to the fold axis as a mode I fracture. For slopes that strike parallel to the fold axis, these two discontinuity sets may produce three structurally-controlled modes of slope failure. For slopes that are coincident with bedding, planar failures along S 0 /S 1 commonly occur and can be very large. Where bedding dips favorably into the slope, failures along joint set S 2 and across bedding can occur. Toppling failures are common to both of these slope configurations, along S 2 and S 0 /S 1 , respectively. Lastly, flat or shallow dipping S 0 /S 1 fractures, even those favorably oriented, and intersecting S 2 joints define blocks that can be mobilized by high ground-water pressures. An example is presented for each slope configuration to illustrate these kinematic controls on slope stability.

On Differential Equations with Codimension-$n$ Discontinuity Sets

2021 ◽  
Vol 20 (3) ◽  
pp. 1348-1381
Author(s):  
Peter L. Varkonyi ◽  
Mate Antali
Keyword(s):  
Differential Equations ◽  
Discontinuity Sets

scholarly journals Local calibrations for minimizers of the Mumford–Shah functional with rectilinear discontinuity sets

2000 ◽  
Vol 79 (2) ◽  
pp. 141-162 ◽  
Author(s):  
Gianni Dal Maso ◽  
Maria Giovanna Mora ◽  
Massimiliano Morini
Keyword(s):  
Discontinuity Sets

A Fast Clustering Method for Identifying Rock Discontinuity Sets

2018 ◽  
Vol 23 (2) ◽  
pp. 556-566 ◽  
Author(s):  
Feng Gao ◽  
Dapeng Chen ◽  
Keping Zhou ◽  
Wenjing Niu ◽  
Hanwen Liu
Keyword(s):  
Clustering Method ◽  
Rock Discontinuity ◽  
Discontinuity Sets
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