scholarly journals ANALYSIS OF MEASURED AND PREDICTED LAND SURFACE SUBSIDENCES CAUSED BY RETREAT MINING

2013 ◽  
Vol 35 (1) ◽  
pp. 143-156
Author(s):  
Tadeusz Majcherczyk ◽  
Katarzyna Kryzia

Abstract This article presents the impact of the retreat mining (i.e., involving an intended collapse of the excavation roof, subsequent to extraction) on the subsidence of the ground surface. The analysis was carried out for two areas of coal underground mining located in the Upper Silesian Coal Basin (Górnośląskie Zagłębie Węglowe). The assessment of the influence of exploitation on the ground surface was based on the results of geodetic measurements performed over a long period of time, whereas the land deformation prediction was made with the use of the EDNOPN program. The calculated and the predicted values were further compared, and the parameters of theory were determined. The results discussed in this paper have been shown by way of diagrams. The observed differences in the processes of vertical displacement were used in the analysis which took into account the degree to which the rock mass had been disturbed during the previous excavations, as well as the type of incumbent rock in the area under study.

2021 ◽  
Vol 13 (5) ◽  
pp. 874
Author(s):  
Yu Chen ◽  
Mohamed Ahmed ◽  
Natthachet Tangdamrongsub ◽  
Dorina Murgulet

The Nile River stretches from south to north throughout the Nile River Basin (NRB) in Northeast Africa. Ethiopia, where the Blue Nile originates, has begun the construction of the Grand Ethiopian Renaissance Dam (GERD), which will be used to generate electricity. However, the impact of the GERD on land deformation caused by significant water relocation has not been rigorously considered in the scientific research. In this study, we develop a novel approach for predicting large-scale land deformation induced by the construction of the GERD reservoir. We also investigate the limitations of using the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) mission to detect GERD-induced land deformation. We simulated three land deformation scenarios related to filling the expected reservoir volume, 70 km3, using 5-, 10-, and 15-year filling scenarios. The results indicated: (i) trends in downward vertical displacement estimated at −17.79 ± 0.02, −8.90 ± 0.09, and −5.94 ± 0.05 mm/year, for the 5-, 10-, and 15-year filling scenarios, respectively; (ii) the western (eastern) parts of the GERD reservoir are estimated to move toward the reservoir’s center by +0.98 ± 0.01 (−0.98 ± 0.01), +0.48 ± 0.00 (−0.48 ± 0.00), and +0.33 ± 0.00 (−0.33 ± 0.00) mm/year, under the 5-, 10- and 15-year filling strategies, respectively; (iii) the northern part of the GERD reservoir is moving southward by +1.28 ± 0.02, +0.64 ± 0.01, and +0.43 ± 0.00 mm/year, while the southern part is moving northward by −3.75 ± 0.04, −1.87 ± 0.02, and −1.25 ± 0.01 mm/year, during the three examined scenarios, respectively; and (iv) the GRACE-FO mission can only detect 15% of the large-scale land deformation produced by the GERD reservoir. Methods and results demonstrated in this study provide insights into possible impacts of reservoir impoundment on land surface deformation, which can be adopted into the GERD project or similar future dam construction plans.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2998 ◽  
Author(s):  
Krzysztof Skrzypkowski

The article presents the impact of geological and mining factors on the stability of room excavations in the Legnica-Głogów Copper District (LGOM) in Poland. In underground mining, the primary task of bolting of mining excavations is to ensure their stability as an essential condition of work safety. Appreciating the role and importance of the rock bolting in Polish ore mining; rock bolt load sensors were designed, manufactured and tested under laboratory conditions. The purpose of the research was to characterize the sensors and determine the elastic range of the bearing plate, which are an integral part of the sensor. The sensors have been verified in industrial conditions. The tests were carried out in the underground copper ore mine in Poland. Three rooms in the exploitation field were selected for testing, where exploitation was carried out at a depth of 809–820 m below the ground surface with the application of room and pillar with roof deflection and maintaining the central part of the field. The exploitation field included 60 rooms and pillars. The effectiveness of the mechanical load sensor of the expansion rock bolt support has been experimentally confirmed. Based on mine research, it was found that the largest increases in the load of the rock bolting, vertical stress and convergence occur in the middle of the mining field.


Author(s):  
S. Thapa ◽  
R. S. Chatterjee ◽  
K. B. Singh ◽  
D. Kumar

Differential SAR-Interferometry (D-InSAR) is one of the potential source to measure land surface motion induced due to underground coal mining. However, this technique has many limitation such as atmospheric in homogeneities, spatial de-correlation, and temporal decorrelation. Persistent Scatterer Interferometry synthetic aperture radar (PS-InSAR) belongs to a family of time series InSAR technique, which utilizes the properties of some of the stable natural and anthropogenic targets which remain coherent over long time period. In this study PS-InSAR technique has been used to monitor land subsidence over selected location of Jharia Coal field which has been correlated with the ground levelling measurement. This time series deformation observed using PS InSAR helped us to understand the nature of the ground surface deformation due to underground mining activity.


2021 ◽  
Vol 13 (2) ◽  
pp. 179
Author(s):  
Yonghong Zhang ◽  
Hongan Wu ◽  
Mingju Li ◽  
Yonghui Kang ◽  
Zhong Lu

Interferometric synthetic aperture radar (InSAR) mapping of localized ground surface deformation has become an important tool to manage subsidence-related geohazards. However, monitoring land surface deformation using InSAR at high spatial resolution over a large region is still a formidable task. In this paper, we report a research on investigating ground subsidence and the causes over the entire 107, 200 km2 province of Jiangsu, China, using time-series InSAR. The Sentinel-1 Interferometric Wide-swath (IW) images of 6 frames are used to map ground subsidence over the whole province for the period 2016–2018. We present processing methodology in detail, with emphasis on the three-level co-registration scheme of S-1 data, retrieval of mean subsidence velocity (MSV) and subsidence time series, and mosaicking of multiple frames of results. The MSV and subsidence time series are generated for 9,276,214 selected coherent pixels (CPs) over the Jiangsu territory. Using 688 leveling measurements in evaluation, the derived MSV map of Jiangsu province shows an accuracy of 3.9 mm/year. Moreover, subsidence causes of the province are analyzed based on InSAR-derived subsidence characteristics, historical optical images, and field-work findings. Main factors accounting for the observed subsidence include: underground mining, groundwater withdrawal, soil consolidations of marine reclamation, and land-use transition from agricultural (paddy) to industrial land. This research demonstrates not only the capability of S-1 data in mapping ground deformation over wide areas in coastal and heavily vegetated region of China, but also the potential of inferring valuable knowledge from InSAR-derived results.


Author(s):  
Sikora Paweł

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.


2020 ◽  
Vol 12 (11) ◽  
pp. 1733
Author(s):  
Paweł Ćwiąkała ◽  
Wojciech Gruszczyński ◽  
Tomasz Stoch ◽  
Edyta Puniach ◽  
Dawid Mrocheń ◽  
...  

This article presents a case study that demonstrates the applicability of unmanned aerial vehicle (UAV) photogrammetric data to land surface deformation monitoring in areas affected by underground mining. The results presented include data from two objects located in the Upper Silesian Coal Basin in Poland. The limits of coordinate and displacement accuracy are determined by comparing UAV-derived photogrammetric products to reference data. Vertical displacements are determined based on differences between digital surface models created using UAV imagery from several measurement series. Interpretation problems related to vegetation growth on the terrain surface that significantly affect vertical displacement error are pointed out. Horizontal displacements are determined based on points of observation lines established in the field for monitoring purposes, as well as based on scattered situational details. The use of this type of processing is limited by the need for unambiguous situational details with clear contours. Such details are easy to find in urbanized areas but difficult to find in fields and meadows. In addition, various types of discontinuous deformations are detected and their development over time is presented. The results are compared to forecasted land deformations. As a result of the data processing, it has been estimated that the accuracy of the determination of XY coordinates and the horizontal displacements (RMS) in best case scenario is on the level of 1.5–2 GSD, and about 2–3 GSD for heights and subsidence.


2020 ◽  
Vol 19 ◽  
pp. 37-48
Author(s):  
Marek Kruczkowski

The paper is a case study of ground surface subsidence induced by a long-term mining of hard coal. Knothe prediction model is commonly used in Poland as a technique for prediction of the subsidence-related deformation of ground surface. The presented issue is related to assumptions about the value of the theory parameters in long-term forecasts on the impact of mining on the surface, which are included in the mine development plan. Incorrectly selected values can significantly influence the quality of deformation forecasts. The calculations presented in the article were made for the area where the exploitation of six coal seams lasted more than thirty years. At the same time, deformations of the surface were observed by means of geodetic measurements. Based on the subsidence curves of the observation line points over time, three periods of rock movement decrease were determined. The range of mining operations was determined for the periods of decreased rock movements. The parameters of Knothe’s model were identified on the basis of geodetic measurements for extracted coal seams. Parametric calculations were made for the increasing range of mining operations and for the ranges of operation between subsequent decreases in the movements of the rock mass. Identification of the parameters of the theory thus made it possible to trace changes in the parameter values for different mining ranges. Significant changes were noted for the parameter describing the dispersion of influence (tanβ), while changes in the coefficient of roof control are not significant and their value becomes stable after some time. As the extent of the mining exploitation was increasing, its influence on both parameters (tangent of angle of major influence – tanβ and coefficient of roof control ‘a’) were evaluated. The changes of tanβ values were found to be significant whereas the changes of the ‘a’ coefficient value are negligible and its value seems to be constant after the initial stage of mining.


2013 ◽  
Vol 58 (4) ◽  
pp. 1347-1357 ◽  
Author(s):  
Roman Ścigała

Abstract The characteristic of specialized computer programs has been presented, serving for identification of W. Budryk-S. Knothe theory parameters, used for description of asymptotic state of post-mining deformations, as well as for transient state. The software is the result of several years of authors’ work. It is a part of complete software system designed for forecasting of underground mining influences on the rock mass and land surface and graphical processing of calculations results. Apart from software description, a short example of its practical utilization has been attached.


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