Estimation Of The Mining Damage Risk In The Hypothetical Impact Area Of The Concurrent Processes Of Rock Mass Disorders

2015 ◽  
Vol 60 (4) ◽  
pp. 889-903 ◽  
Author(s):  
Wiesław Piwowarski ◽  
Zbigniew Isakow ◽  
Jacek Juzwa
Keyword(s):  
Rock Mass ◽  
Mass Medium ◽  
Local Maximum ◽  
Mining Operation ◽  
Mining Area ◽  
Theoretical Description ◽  
Uncertain Information ◽  
Impact Area ◽  
Concurrent Processes ◽  
The Impact

Abstract The aim of this work is the estimation of the risk of mining damage occurrence, based on uncertain information regarding the impact of the concurrent processes of deformation and vibration. This problem concerns the experimental and theoretical description of the so-called critical phenomena occurring during the reaction mining area ↔ building object. Post-mining deformations of the rock mass medium and paraseismic vibrations can appear at a considerable distance from the sub-area of the mining operation – hence, the determination of the measures of their impacts is usually somewhat subjective, while the estimation of the mining damage based on deterministic methods is often insufficient. It is difficult to show the correlation between the local maximum of the impact of the velocity vector amplitude and the damage to the building – especially if the measures of interaction are not additive. The parameters of these impacts, as registered by measurements, form finite sets with a highly random character. Formally, it is adequate to the mapping from the probability space to the power set. For the purposes of the present study, the Dempster – Shafer model was used, where space is characterised by subadditive and superadditive measures. Regarding the application layer, the conclusions from the expert evaluations are assumed to be the values of random variables. The model was defined, and the risk of damage occurrence was estimated.

scholarly journals Impact of Industrial Pollution on Radial Growth of Conifers in a Former Mining Area in the Eastern Carpathians (Northern Romania)

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 640
Author(s):  
Cristian Gheorghe Sidor ◽  
Radu Vlad ◽  
Ionel Popa ◽  
Anca Semeniuc ◽  
Ecaterina Apostol ◽  
...  
Keyword(s):  
Air Pollution ◽  
Industrial Pollution ◽  
Radial Growth ◽  
Abies Alba ◽  
Mining Operation ◽  
Mining Area ◽  
Silver Fir ◽  
Local Pollution ◽  
Eastern Carpathians ◽  
The Impact

The research aims to evaluate the impact of local industrial pollution on radial growth in affected Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.) stands in the Tarnița study area in Suceava. For northeastern Romania, the Tarnița mining operation constituted a hotspot of industrial pollution. The primary processing of non-ferrous ores containing heavy metals in the form of complex sulfides was the main cause of pollution in the Tarnița region from 1968 to 1990. Air pollution of Tarnița induced substantial tree growth reduction from 1978 to 1990, causing a decline in tree health and vitality. Growth decline in stands located over 6 km from the pollution source was weaker or absent. Spruce trees were much less affected by the phenomenon of local pollution than fir trees. We analyzed the dynamics of resilience indices and average radial growth indices and found that the period in which the trees suffered the most from local pollution was between 1978 and 1984. Growth recovery of the intensively polluted stand was observed after the 1990s when the environmental condition improved because of a significant reduction in air pollution.

scholarly journals Identification of the ground movements caused by mining-induced seismicity with the satellite interferometry

2020 ◽  
Vol 382 ◽  
pp. 297-301
Author(s):  
Ryszard Hejmanowski ◽  
Wojciech T. Witkowski ◽  
Artur Guzy ◽  
Agnieszka Malinowska
Keyword(s):  
Rock Mass ◽  
Induced Seismicity ◽  
Mining Area ◽  
Ground Movements ◽  
Mining Induced Seismicity ◽  
Rock Mass Deformation ◽  
Surface Vibrations ◽  
Satellite Radar ◽  
The Impact ◽  
Total Subsidence

Abstract. The assessment of the impact of mining-induced seismicity on the natural environment and infrastructure is often limited to the analysis of terrain surface vibrations. However, similar seismic phenomena, like earthquakes, may also imply dislocations and deformations of the rock mass. Such ground movements may occur in areas which are not directly under the influence of the mining. The study of the displacement field caused by mining-induced seismicity is usually carried out with the use of geodetic methods. Classical geodetic measurements provide discrete information about observed ground movements. As a result, they generally do not provide spatially and temporally relevant estimates of the total range and values of ground movements for specific periods of interest. Moreover, mining-induced seismicity causes a severe threat to buildings. That is why, regarding the complexity of the mechanism of occurrence of mining-induced seismicity and their impact on ground movements, this problem remains a substantial research issue. The presented research aimed to analyse the ground movements caused by mining-induced seismicity. The ground displacements were established based on data from Sentinel-1 satellites applying differential interferometric synthetic aperture radar (DInSAR). The results of the investigation in the copper mining area of the Lower Silesia region of Poland revealed that the observed subsidence caused by mining-induced seismicity usually has a shape of a regular ellipse. The radius of these ground movements does not exceed approximately 2–3 km from the mining-induced tremor's epicenter, and the total subsidence reaches ca. 10–20 cm. More than 50 % of the total subsidence is observed on the surface within a few days after the mining tremor occurrence. Furthermore, the deformations of the surface occur when the energy of mining-induced tremor reaches values of the order of 105 J or higher. The presented research can contribute to better identification and evaluation of the mechanism of the rock mass deformation process caused by mining-induced seismicity. In addition, the use of satellite radar interferometry improves the quality of monitoring of these dynamic phenomena significantly. The data retrieved using this method allow for quasi-continuous monitoring of the local subsidence bowls caused by mining-induced seismicity.

The Numerical Simulation Research on the Groundwater Environmental Impact of Coal Mining in Complex Boundary Conditions

2015 ◽  
Vol 737 ◽  
pp. 868-873
Author(s):  
Yong Li Shi ◽  
Yong Bo Zhang ◽  
Xing Hua Ren
Keyword(s):  
Boundary Conditions ◽  
Coal Mining ◽  
Coal Mines ◽  
Mining Operation ◽  
Mining Area ◽  
Simulation Research ◽  
Groundwater Exploitation ◽  
Groundwater Environment ◽  
Complex Boundary ◽  
The Impact

The article takes Shanxi Lu’an Group Yuxin Coal Mines as an example, establishing a model to simulate the impact of groundwater processes in different time periods Yuxin mining process through MODFLOW software. And evaluates the predictive region groundwater level and groundwater environment changing trends run of mine production.Model fit with satisfactory results. Due to there's watershed area in groundwater exploitation and the groundwater flow along the limestone layer excretion which is in the valley around, the groundwater has three flow directions in the Mining area and the flow field is very complex.Obviously,it is more difficult to understand the mining impact on groundwater exploit ation process. The article combines theoretical study with practical investigation. According to the simulation results of Yuxin Coal Mines, showing more clearly the impact of coal mining under complex boundary conditions on groundwater. Provide for the study of the impact of post-mining groundwater reference, while providing the basis for the supervision and management of local government departments and post Yuxin coal mining operation, and also provide a favorable basis for the protection of drinking water for local residents.

scholarly journals Simulation Possibilites of the Post-Mining Goafs Impact on the Deformations Induced by Next Underground Mining Operations with Use of the Cellular Automata Method

2020 ◽  
Author(s):  
Sikora Paweł
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
Mining Area ◽  
Mining Operations ◽  
New Approach ◽  
Upper Silesian Coal Basin ◽  
Under Construction ◽  
The Impact ◽  
Further Development

Abstract Underground mining operations in the area of a rock mass affected by previous exploitation may cause additional deformations to appear on the surface. The size of these deformations can be significant, and their character is often non-linear. The nature of these deformations cannot be justified solely by the impact of current mining operations. At the same time, the predictive method of S. Knothe, widely used in Poland, does not explicitly include these types of phenomena. In the area of intensive and long-term mining exploitation, such as the Upper Silesian Coal Basin, the practical possibility of simulating this occurrence may be helpful in the planning of new mining exploitation under construction objects. Today we are usually limited to numerical modelling methods like finite difference method (FDM). This one base on the principle of mechanical similarity. The theoretical usefulness of method (and its similar) has already been proven many times. The main impediment to its practical application is the lack of recognition of the rock mass in terms of its mechanical properties. The presented method is a new approach to the possibility of modelling the subject phenomenon. The method has not been used in practical forecasting mining area deformation caused by underground deposits mining. It’s characterized by a huge potential for further development.

The Impact of Effluents from a Uranium Mine and Mill Complex in Northern Saskatchewan on Contaminant Concentrations in Receiving Waters and Sediments

1987 ◽  
Vol 22 (4) ◽  
pp. 559-569 ◽  
Author(s):  
Thomas P. Hynes ◽  
Randy M. Schmidt ◽  
Tim Meadley ◽  
Neill A. Thompson
Keyword(s):  
Major Ions ◽  
Mining Operation ◽  
Uranium Mining ◽  
Uranium Mine ◽  
Northern Saskatchewan ◽  
Receiving Waters ◽  
The Impact

Abstract Data are provided on the release of 5 radionuclides, 17 metals and 7 major ions from a uranium mining operation in northern Saskatchewan. The downstream concentration of these contaminants is documented, and the point of “no discernible impact” is determined. Sediments in a downstream lake are monitored for uranium and molybdenum, and the post-release fate of these metals is discussed.

scholarly journals Aircraft Impact Effects on an Aged NPP

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 816
Author(s):  
Rosa Lo Frano
Keyword(s):  
Nuclear Power ◽  
Military Aircraft ◽  
Residual Resistance ◽  
Plant Safety ◽  
Need To Evaluate ◽  
Target Wall ◽  
Impact Area ◽  
Wall Perforation ◽  
The Impact ◽  
Loss Of Strength

The impact of an aircraft is widely known to be one of the worst events that can occur during the operation of a plant (classified for this reason as beyond design). This can become much more catastrophic and lead to the loss of strength of/collapse of the structures when it occurs in the presence of ageing (degradation and alteration) materials. Therefore, since the performance of all plant components may be affected by ageing, there is a need to evaluate the effect that aged components have on system performance and plant safety. This study addresses the numerical simulation of an aged Nuclear Power Plant (NPP) subjected to a military aircraft impact. The effects of impact velocity, direction, and location were investigated together with the more unfavorable conditions to be expected for the plant. The modelling method was also validated based on the results obtained from the experiments of Sugano et al., 1993. Non-linear analyses by means of finite element (FE) MARC code allowed us to simulate the performance of the reinforced concrete containment building and its impact on plant availability and reliability. The results showed that ageing increases a plant’s propensity to suffer damage. The damage at the impact area was confirmed to be dependent on the type of aircraft involved and the target wall thickness. The greater the degradation of the materials, the lower the residual resistance capacity, and the greater the risk of wall perforation.

scholarly journals Influence of the Spatial Pressure Distribution of Breaking Wave Loading on the Dynamic Response of Wolf Rock Lighthouse

2021 ◽  
Vol 9 (1) ◽  
pp. 55
Author(s):  
Darshana T. Dassanayake ◽  
Alessandro Antonini ◽  
Athanasios Pappas ◽  
Alison Raby ◽  
James Mark William Brownjohn ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Pressure Distribution ◽  
Distinct Element ◽  
Breaking Waves ◽  
Breaking Wave ◽  
Wave Loading ◽  
Wave Impact ◽  
Pressure Distributions ◽  
Impact Area ◽  
The Impact

The survivability analysis of offshore rock lighthouses requires several assumptions of the pressure distribution due to the breaking wave loading (Raby et al. (2019), Antonini et al. (2019). Due to the peculiar bathymetries and topographies of rock pinnacles, there is no dedicated formula to properly quantify the loads induced by the breaking waves on offshore rock lighthouses. Wienke’s formula (Wienke and Oumeraci (2005) was used in this study to estimate the loads, even though it was not derived for breaking waves on offshore rock lighthouses, but rather for the breaking wave loading on offshore monopiles. However, a thorough sensitivity analysis of the effects of the assumed pressure distribution has never been performed. In this paper, by means of the Wolf Rock lighthouse distinct element model, we quantified the influence of the pressure distributions on the dynamic response of the lighthouse structure. Different pressure distributions were tested, while keeping the initial wave impact area and pressure integrated force unchanged, in order to quantify the effect of different pressure distribution patterns. The pressure distributions considered in this paper showed subtle differences in the overall dynamic structure responses; however, pressure distribution #3, based on published experimental data such as Tanimoto et al. (1986) and Zhou et al. (1991) gave the largest displacements. This scenario has a triangular pressure distribution with a peak at the centroid of the impact area, which then linearly decreases to zero at the top and bottom boundaries of the impact area. The azimuthal horizontal distribution was adopted from Wienke and Oumeraci’s work (2005). The main findings of this study will be of interest not only for the assessment of rock lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with steep foreshore slopes) and exposed to harsh breaking wave loading.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Grinding Force Model for Low-Speed Grinding Based on Impact Principle

2013 ◽  
Vol 797 ◽  
pp. 123-128
Author(s):  
Ming He Liu ◽  
Xiu Ming Zhang ◽  
Shi Chao Xiu
Keyword(s):  
Sliding Friction ◽  
Impact Load ◽  
Grinding Force ◽  
Calculation Model ◽  
Force Model ◽  
Grinding Process ◽  
Low Speed ◽  
Impact Area ◽  
Force Mechanism ◽  
The Impact

In the low-speed grinding process, the force generated when the wheel grinding the workpiece is the result of sliding friction, plough and cutting. While in the actual study, the cutting process has attracted extensive attention. Impact effect to the entire grinding process on the contact is ignored so that the error exists between the calculation grinding force and the measured grinding force. Basing on the shock effect to the grinding process, the paper divides the contact area into impact area and cutting area. And the model of impact load generated from single grit is built. Moreover, the grinding force theoretical calculation model and total grinding force mathematical model is also constructed by analyzing the impact load affecting on the grinding force mechanism. Finally experimental study verifies the correctness of theoretical analysis.

scholarly journals Design of a computational model for multi-body contact of deformable bodies in the flowing fluid

2018 ◽  
Vol 157 ◽  
pp. 02012 ◽  
Author(s):  
Marián Handrik ◽  
Milan Vaško
Keyword(s):  
Computational Model ◽  
Time Intervals ◽  
Flowing Fluid ◽  
Body Contact ◽  
Impact Area ◽  
Deformable Bodies ◽  
Multi Body ◽  
The Impact ◽  
Design And Testing

The article deals with the design and testing of a computational model for multi-body contact of deformable bodies in the flowing fluid. The computational model will be designed to allow easy modify the impact area of deformable bodies and their shape. The computational model must allow the application of an endless cycle of bodies impact with the possibility of restarting and calculating the following time intervals for collision of bodies.

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