scholarly journals A Rapid Method of the Rock Mass Surface Reconstruction for Surface Deformation Detection at Close Range

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5371
Author(s):  
Qijun Hu ◽  
Chunlin Ma ◽  
Yu Bai ◽  
Leping He ◽  
Jie Tan ◽  
...  
Keyword(s):  
Rock Mass ◽  
Surface Reconstruction ◽  
Feature Detection ◽  
Surface Deformation ◽  
Progressive Failure ◽  
Survey Period ◽  
Mass Model ◽  
Before And After ◽  
Close Range ◽  
Point Detection

Characterizing the surface deformation during the inter-survey period could assist in understanding rock mass progressive failure processes. Moreover, 3D reconstruction of rock mass surface is a crucial step in surface deformation detection. This study presents a method to reconstruct the rock mass surface at close range in a fast way using the improved structure from motion—multi view stereo (SfM) algorithm for surface deformation detection. To adapt the unique feature of rock mass surface, the AKAZE algorithm with the best performance in rock mass feature detection is introduced to improve SfM. The surface reconstructing procedure mainly consists of image acquisition, feature point detection, sparse reconstruction, and dense reconstruction. Hereafter, the proposed method was verified by three experiments. Experiment 1 showed that this method effectively reconstructed the rock mass model. Experiment 2 proved the advanced accuracy of the improved SfM compared with the traditional one in reconstructing the rock mass surface. Eventually, in Experiment 3, the surface deformation of rock mass was quantified through reconstructing images before and after the disturbance. All results have shown that the proposed method could provide reliable information in rock mass surface reconstruction and deformation detection.

scholarly journals Directional Hydraulic Fracturing (DHF) of the Roof, as an Element of Rock Burst Prevention in the Light of Underground Observations and Numerical Modelling

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 562
Author(s):  
Marek Jendryś ◽  
Andrzej Hadam ◽  
Mateusz Ćwiękała
Keyword(s):  
Rock Mass ◽  
Hydraulic Fracturing ◽  
Coal Mining ◽  
Rock Burst ◽  
Coal Mine ◽  
Seismic Activity ◽  
Black Coal ◽  
Directional Hydraulic Fracturing ◽  
Before And After ◽  
The Face

The following article analyzes the effectiveness of directional hydraulic fracturing (DHF) as a method of rock burst prevention, used in black coal mining with a longwall system. In order to define changes in seismic activity due to DHF at the “Rydułtowy” Black Coal Mine (Upper Silesia, Poland), observations were made regarding the seismic activity of the rock mass during coal mining with a longwall system using roof layers collapse. The seismic activity was recorded in the area of the longwall itself, where, on a part of the runway, the rock mass was expanded before the face of the wall by interrupting the continuity of the rock layers using DHF. The following article presents measurements in the form of the number and the shock energy in the area of the observed longwall, which took place before and after the use of DHF. The second part of the article unveils the results of numerical modeling using the discrete element method, allowing to track the formation of goafs for the variant that does not take DHF into consideration, as well as with modeled fractures tracing DHF carried out in accordance with the technology used at “Rydułtowy” coal mine.

Research on Number of High-Pressure Grouting of Hierarchical Multiple for Slope Based on Reliability Analysis

2014 ◽  
Vol 716-717 ◽  
pp. 363-369
Author(s):  
Zhen Hua Xie ◽  
Dong Yang ◽  
Sha Sha Liang ◽  
Zhi Yun Jia
Keyword(s):  
High Pressure ◽  
Rock Mass ◽  
System Analysis ◽  
Rock Surface ◽  
Rock Permeability ◽  
Iron Mine ◽  
Probability Calculation ◽  
Before And After ◽  
Pressure Grouting ◽  
First Time

The technology of hierarchical multiple high-pressure grouting is an effective approach to manage high and steep slope of broken rock mass. The number of grouting is one of the key parameters of this technology. By the analysis of mechanics and grouting theory, the anchoring effect mainly is affected by anchor slurry vein and the contact area with rock mass. Based on the system analysis of slurry vein development for first time and many times high-pressure grouting, the process flow for hierarchical multiple high-pressure grouting is put forward. Serve the rock permeability changes before and after grouting as an indicator measuring slurry and rock surface area, the method of determining grouting number based on the reliable probability is got. Combined with the engineering example of Shouyun Iron Mine, this paper puts forward the reliability criteria of working state of hierarchical multiple high-pressure grouting. Through the probability calculation, the best number of grouting is 4 times. The tests of permeability of rock mass and drawing force verify the accuracy of this determination method.

scholarly journals Joint Investigation and 3D Visual Evaluation of Rock Mass Quality

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Haiping Yuan ◽  
Chenghao Chen ◽  
Yixian Wang ◽  
Hanbing Bian ◽  
Yan Liu
Keyword(s):  
Rock Mass ◽  
Quality Evaluation ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Rock Mass Classification ◽  
National Standard ◽  
Ratio Method ◽  
Rock Mass Quality ◽  
Close Range ◽  
Mass Classification

In order to realize the high efficiency quality classification and three-dimensional visualization of engineering rock mass and to solve the technical difficulties of the traditional rock mass quality evaluation method such as high labor intensity, long process time consumption, many intervention processes such as scale measurement and manual calculation, and nonintuitive classification results, this paper puts forward a 3D visual rock mass quality evaluation method and system based on close-range photography, which optimizes the traditional rock mass quality evaluation method, makes the rock mass classification three-dimensional and visible, and realizes the estimation of unrevealed rock mass quality evaluation index. The research results show the following: (1) The method of storing joint information by close-range photography and extracting joint information by human-computer interaction improves the working efficiency and the process is safe and controllable compared with the traditional method of collecting fracture parameters. (2) Based on the statistical analysis of 97 groups of roadway survey data, the comprehensive statistical regression formula between BQ value of Chinese national standard and RMR value is given, and there is a good correlation between BQ value and RMR value of rock mass quality index. (3) Based on the power-inverse ratio method, the three-dimensional model of rock mass classification of the mine was established, and the cutting model obtained the current distribution diagram of rock mass quality grade, providing scientific reference for drilling, blasting, support, and other production design optimizations.

scholarly journals CONTEMPORARY GEODYNAMICS OF THE GAROMAI ACTIVE FAULT (SAKHALIN ISLAND)

2019 ◽  
Vol 10 (2) ◽  
pp. 561-567
Author(s):  
N. F. Vasilenko ◽  
A. S. Prytkov
Keyword(s):  
Fault Zone ◽  
Active Fault ◽  
Surface Deformation ◽  
Fault Zones ◽  
Sakhalin Island ◽  
Tectonic Activity ◽  
Relative Deformation ◽  
Survey Period ◽  
Potential Threat ◽  
Deformation Processes

In the northern Sakhalin Island, the tectonic activity of the fault zones is a potential threat to the industrial infrastructure of the petroleum fields. Recently, the background seismicity has increased at the Hokkaido‐Sakhalin fault that consists of several segments, including the Garomai active fault. In the studies of the regional deformation processes, it is important not only to analyze the seismic activity, but also to quantitatively assess the dynamics of deformation accumulation in the fault zones. In order to study the contemporary geodynamics of the Garomai fault, a local GPS/GLONASS network has been established in the area wherein trunk oil and gas pipelines are installed across the fault zone. Based on the annual periodic measurements taken in 2006–2016, we study the features of surface deformation and calculate the rates of displacements caused by the tectonic activity in the fault zone. During the survey period, no significant displacement of the fault wings was revealed. In the immediate vicinity of the fault zone, multidirectional horizontal displacements occur at a rate up to 1.6 mm/yr, and uplifting of the ground surface takes place at a rate of 3.4 mm/yr. This pattern of displacements is a reflection of local deformation processes in the fault zone. At the western wing of the fault, a maximum deformation rate amounts to 1110–6 per year. The fault is a boundary mark of a transition from lower deformation rates at the eastern wing to higher ones at the west wing. In contrast to the general regional compression setting that is typical of the northern Sakhalin Island, extension is currently dominant in the Garomai fault zone. The estimated rates of relative deformation in the vicinity of the Garomai fault give grounds to classify it as ‘hazardous’.

Catastrophe Theory Analysis of Rock Mass Dynamic Destabilization

2012 ◽  
Vol 166-169 ◽  
pp. 2774-2781
Author(s):  
Yong Zhang ◽  
Da Jian Hu ◽  
Lu Xue
Keyword(s):  
Rock Mass ◽  
Elastic Energy ◽  
Quantitative Description ◽  
Scientific Basis ◽  
Rock System ◽  
Catastrophe Model ◽  
Rock Stability ◽  
Before And After ◽  
The Given ◽  
First Time

In step with body Ⅱ, analytic solution and illustration of elastic energy releasing amount of rock mass dynamic destabilization are given for the first time in the form of precise and approximate catastrophe model. It is upgraded from qualitative understand to quantitative description that study on rock stability at the stage before and after earthquake and rockburst. The halting point’s position of rock mass dynamic destabilization is ascertained strictly, and it offers scientific basis for the calculation on earthquake efficiency, the study on earthquake energy magnitude released, earthquake stress drop, fault offset after earthquake and amount of elastic strain recovery of surrounding rock. The system possesses the capability of applying work to surroundings when it destabilizes, and earthquake wave energy is the work that destabilizing rock system applies to surroundings by way of destructive. The given illustration of elastic energy releasing amount implicates wealth of information, it produces credible evidence for confirming that the mathematical abstract of rock dynamic destabilization is fold catastrophe model.

Physical experiment investigation on progressive deformation of shear slip surface of the soil slope

2021 ◽  
Author(s):  
Qiang Xie ◽  
Yuxin Ban ◽  
Zhihui Wu ◽  
Xiang Fu
Keyword(s):  
High Frequency ◽  
Surface Deformation ◽  
Slip Surface ◽  
Progressive Failure ◽  
Surface Displacement ◽  
Soil Slope ◽  
Progressive Deformation ◽  
Shear Surface ◽  
Time Frequency ◽  
Ae Signal

<p>The sliding surface deformation of the soil slope mainly presents progressive failure characteristics, and serial acoustic emission (AE) signals are generated during the deformation process of progressive landslide. A model test aiming at reproducing the typical shear surface deformation of a soil slope is designed. The displacement, AE data and corresponding time-frequency characteristics are comprehensively analyzed to evaluate the progressive deformation behavior. Comparisons with different granular backfills measurements show that cumulative AE count increase proportionally with the shear surface displacement, and the experiments demonstrate that the glass sand backfill exhibits remarkable AE detection characteristics and stronger correlation results. Significantly, AE signal exhibits variational dominant frequencies at different deformation stages, and there is the significant phenomenon that not only the low frequency signals generated with a significantly increase number, at the same time the continuous high frequency signals appear during the accelerating deformation stage. Furthermore, from the statistical trend of the energy percentage of the high frequency band into 312.5~500 kHz, it’s found that the correlative energy proportion occupies up to 15%, or even higher during the accelerating stage, indicating that the landslide may be about to enter a severely dangerous stage. The experiments show that the frequency characteristic of the AE signal can be effectively used as the early warning index, which may be the promising reference of the field warning monitoring for the soil progressive landslides.</p>

Twenty-ninth Canadian Geotechnical Colloquium: The role of advanced numerical methods and geotechnical field measurements in understanding complex deep-seated rock slope failure mechanisms

2008 ◽  
Vol 45 (4) ◽  
pp. 484-510 ◽  
Author(s):  
Erik Eberhardt
Keyword(s):  
Rock Mass ◽  
Numerical Modelling ◽  
Slope Failure ◽  
Rock Slope ◽  
Current Knowledge ◽  
Progressive Failure ◽  
Strength Degradation ◽  
Rock Slope Stability ◽  
Clear Understanding ◽  
Rock Mass Strength

The underlying complexity associated with deep-seated rock slope stability problems usually restricts their treatment to phenomenological studies that are largely descriptive and qualitative. Quantitative assessments, when employed, typically focus on assessing the stability state but ignore factors related to the slope’s temporal evolution including rock mass strength degradation, internal shearing, and progressive failure, all of which are key processes contributing to the final collapse of the slope. Reliance on displacement monitoring for early warning and the difficulty in interpreting the data without a clear understanding of the underlying mechanisms has led to a situation where predictions are highly variable and generally unreliable. This paper reviews current knowledge regarding prefailure mechanisms of massive rock slopes and current practices used to assess the hazard posed. Advanced numerical modelling results are presented that focus on the importance of stress- and strain-controlled rock mass strength degradation leading to failure initiation. Efforts to address issues related to parameter and model uncertainty are discussed in the context of a high alpine research facility, the “Randa In Situ Rockslide Laboratory”, where state-of-the-art instrumentation systems and numerical modelling are being used to better understand the mechanisms controlling prefailure deformations over time and their evolution leading to catastrophic failure.

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