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Given that traditional joint set identification faces challenges due to labor intensity, safety concerns with accessing steep slopes, and limited sampling locations for measurements, there is an urgent need for more efficient techniques to align with the pace of mine development. This study proposes a deep learning technique for the automated identification of joint sets within 3D point cloud models of rock masses. The process commences with the classification of joints on the 3D surface of a rock mass, accomplished through the training of a deep neural network architecture, and validation using manually labeled datasets. Following this, individual joint surfaces are distinguished using the Density-Based Scan with Noise clustering algorithm. Subsequently, the orientations of the identified joint surfaces are determined by fitting least-square planes using the Random Sample Consensus method. Finally, the joint planes are categorized into distinct joint sets, and the dip direction and dip angle for each set are computed. The effectiveness of this methodology is assessed through a case study, demonstrating that the proposed approach is rapid, precise, and resilient. [ABSTRACT FROM AUTHOR]

In quarries, rock blasting is important for mining and transportation, being the first step in the comminution. Discontinuities present in a rock mass can interrupt the propagation of the shock wave and evacuate gases, thereby reducing the efficiency of the explosives. Differences in the orientation of joint sets and the advancing direction of the mine produce different fragmentation results. In this study, the blastability of a rock mass was evaluated as a function of mining advance direction relative to the direction of the main joint set using particle size curves generated by photo-analysis. The data were analysed for each bench, and the optimal direction of advance was determined as the one to generate the smallest boulders. The particle size curves reveal optimal fragmentation when the mining direction is orthogonal to the main joint set, reducing the number of boulders by 64.40%. [ABSTRACT FROM AUTHOR]

This paper proposes a new technique for performing 3D static-point cloud registration after calibrating a multi-view RGB-D camera using a 3D (dimensional) joint set. Consistent feature points are required to calibrate a multi-view camera, and accurate feature points are necessary to obtain high-accuracy calibration results. In general, a special tool, such as a chessboard, is used to calibrate a multi-view camera. However, this paper uses joints on a human skeleton as feature points for calibrating a multi-view camera to perform calibration efficiently without special tools. We propose an RGB-D-based calibration algorithm that uses the joint coordinates of the 3D joint set obtained through pose estimation as feature points. Since human body information captured by the multi-view camera may be incomplete, a joint set predicted based on image information obtained through this may be incomplete. After efficiently integrating a plurality of incomplete joint sets into one joint set, multi-view cameras can be calibrated by using the combined joint set to obtain extrinsic matrices. To increase the accuracy of calibration, multiple joint sets are used for optimization through temporal iteration. We prove through experiments that it is possible to calibrate a multi-view camera using a large number of incomplete joint sets.

The discontinuity of geological structure on tuff layer of rock slopes in Manado triggered a phenomenon of rock slope instability. Mohr-Coulomb criterion which is commonly used as a method of analysis is not suitable to solve the slope stability problem because this criterion does not consider the condition of the geological structure as one of its factors. This paper analyzed the rock slope stability by accommodate the condition of the geological structure using Hoek-Brown criterion. Geological structure effect in Hoek-Brown criterion was realized in the form of GSI (Geological strength index). Poor geological structure will reduce GSI. In this paper, GSI of tuff has been determined by discontinuities of mapping and back analysis. The results from discontinuities mapping revealed that the rock structures were very blocky to blocky and surface conditions were very poor to poor. GSI value ranges between 20-30. From back analysis with shear strength reduction, GSI value was 20 and UCS value was 230 kN. The results are quite close with the field observation. [ABSTRACT FROM AUTHOR]

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The article offers information on verifying the capability of three- dimensional distinct element code (3DEC) to model wave propagation across rock joints in 3D spaces and also focuses on analyzing the effects of mesh size, joint stiffness and incident angle on wave propagation. For verifying the capability of 3DEC to effectively model the wave propagation in jointed rock masses, a case study is presented. Several diagrams and bar graphs are also presented.

Abstract: Up to 10 properties of joints can be recorded in the field, yet only two (dip and dip direction) are commonly used to identify joint sets. This paper investigates some of the shortcomings of commonly employed methods for joint set clustering, based on an analysis of synthetic and field data. First, eight synthetic joint sets were generated using a normal distribution of joint orientations. Each joint was defined in terms of four properties (dip, dip direction, infilling material and infilling percentage). A Parzen classifier was used to confirm the importance of using all the joint properties in identifying the joint sets. To investigate the generalization ability of this approach, the analysis was extended to 178 joints measured in the field, with seven properties available for each joint. Joints were clustered based on rose diagrams, stereonets, and K-means clustering methods, yielding three, five, and seven joint sets, respectively. Calculation of the coefficient of variation and principal component analysis (PCA) of joint properties resulted in an improvement in clustering, provided that a large number of joint properties are considered. [Copyright &y& Elsevier]

This paper proposes a new technique for performing 3D static-point cloud registration after calibrating a multi-view RGB-D camera using a 3D (dimensional) joint set. Consistent feature points are required to calibrate a multi-view camera, and accurate feature points are necessary to obtain high-accuracy calibration results. In general, a special tool, such as a chessboard, is used to calibrate a multi-view camera. However, this paper uses joints on a human skeleton as feature points for calibrating a multi-view camera to perform calibration efficiently without special tools. We propose an RGB-D-based calibration algorithm that uses the joint coordinates of the 3D joint set obtained through pose estimation as feature points. Since human body information captured by the multi-view camera may be incomplete, a joint set predicted based on image information obtained through this may be incomplete. After efficiently integrating a plurality of incomplete joint sets into one joint set, multi-view cameras can be calibrated by using the combined joint set to obtain extrinsic matrices. To increase the accuracy of calibration, multiple joint sets are used for optimization through temporal iteration. We prove through experiments that it is possible to calibrate a multi-view camera using a large number of incomplete joint sets. [ABSTRACT FROM AUTHOR]

The slope stability analysis has many applications in the engineering projects such as the dams, the roads and open pits structures. The method of analysis is usually based on the equilibrium conditions of the potential plane and wedge failures. The zone of the potential failure is stable whenever the stability forces dominate instability characteristics of the slope. In most of the classic methods of slope stability analysis, the joint surfaces are assumed to be continuous along the potential failure zone. These can cause an underestimated solution to the analysis. In this research the joint trace length is considered to be discontinuous across the potential surface of failure as it happens in nature. Therefore, there exists a rock bridge between the local joint traces. Because of the numerous problems related to the rock slope stability the above assumption is satisfied and the shear strength characteristics of intact rock have taken part in the analysis. The analysis presented here gives a better concept, view, and idea of understanding the physical nature of rock slopes and includes more parameters governing the stability of the potential failure zone. [ABSTRACT FROM AUTHOR]

A series of global hydraulic conductivity and mechanical stiffness tensors for variably saturated true anisotropic intact rock matrices, joints, joint sets, and jointed rock masses is formulated to expand the fully coupled poroelastic governing equations presented by Kim (2004) for groundwater flow and solid skeleton deformation in porous geologic media to those for fractured and fractured porous geologic media. The global hydraulic conductivity tensors are derived from the local hydraulic conductivity tensors using coordinate transformation on the basis of the generalized Darcy’s law. The global mechanical stiffness tensors are then derived from the local or global mechanical compliance tensors using coordinate transformation on the basis of the generalized Hooke’s law. [ABSTRACT FROM AUTHOR]

Abstract: Linear elastic fracture mechanics predicts that joint orientation is controlled by the stress field in which the joints propagate. Thus joint sets are effective proxies for stress trajectories during joint growth. Complexity in joint orientation indicates stress trajectory variability, a phenomenon quantified using an eigenvalue method that measures dispersion of joint normal vectors (i.e. poles) around the mean vector. Ratios between the eigenvalues of a joint orientation tensor give the clustering strength (ζ) and the shape factors (γ) of the distribution. A joint set that forms in a relatively isotropic rock subject to a rectilinear stress field should exhibit strong clustering and small random orientation variation that can be described by the Fisher statistical model. However, most joint orientation distributions in bedded rocks have non-random variation, greater in strike than in dip. This relative stability of the vertical stress orientation is strongest when joints are bounded by bedding interfaces, reflecting the tendency for deflection in the local stress field arising from the growth of side cracks, joint segments and adjacent joints in joint zones. Even when joint growth across bedding interfaces indicates negligible strength anisotropy, joint orientation distributions reflect less joint–joint interaction during vertical growth than during horizontal growth. As strike variation grows due to the presence of a non-rectilinear stress field, the orientation data better fit a Kent statistical model. Joint sets formed during fold development or in rocks with irregular bedding boundaries are more weakly clustered with Fisher-like orientation distributions. Orientation distributions for joint sets formed throughout a stress rotation have Kent-like shapes that indicate the magnitude of stress trajectory variation and clustering strength that depends on the joint density at each increment of the stress rotation. [Copyright &y& Elsevier]

This paper describes a computer approach that has been developed for estimating three-dimensional fracture orientations from two-dimensional fracture trace information gathered from digital images of exposed rock faces. The approach assumes that the fractures occur in sets, and that each set can be described by a mean orientation and a measure of the scatter about the mean. Mathematical relationships are developed that relate the 3D fracture properties with the trace angles that would be measured on one or more rock faces. These algorithms are used in conjunction with a genetic algorithm to invert the trace angles to estimate 3D joint orientation. A number of case studies have been conducted indicating a great potential for the technique. [Copyright &y& Elsevier]

Engineering geologic exploration of the limestone massif "Duboki Potok-Bijela rijeka" was performed continuously since 2002 to nowadays with the aim to determine the exploitation conditions in the quarry. These explorations include detailed recording of all types of discontinuity, statistical and kinematical analysis of a large number of data, as well as identification of their genesis related to regional tectonic structure of the area. Dominant influence on the formation of structural-tectonic forms in limestone massif had movement along the deep seated fault Tinja-Moluhe located in the immediate vicinity. This limestone massif has an anticline form - its north limb is steeper and dips towards the fault Tinja-Moluhe. Detailed kinematical analysis was performed using the stereographic projection, based on slickenside lineation registered on the faults and bedding planes. Obtained results show that the folding and faulting directions of the limestone massif have been triggered by horizontal movements as well as related tectonic blocks shifting along the deep-seated lineament/fault Tinja-Moluhe. Detailed analysis revealed a relationship between join sets and the anticline north limb. [ABSTRACT FROM AUTHOR]