Search Results (10)

Mining-induced land subsidence and geohazards have become increasingly prominent in loess mining areas. Accurate identification of Active Deformation Areas (ADAs) is of great significance for mining safety, ecological protection, and geohazard prevention. The study selected the Binchang mining and used SBAS-InSAR based on Sentinel-1 SAR images from 2020 to 2025 to derive cumulative deformation and velocity. Three ADA identification approaches, including ADAfinder, MCAS-TO, and Light-UNet deep learning method, were quantitatively evaluated using IoU, F1-score, Boundary_F1-score, Precision, Recall, Area Error (%), and comparatively analyzed. ADAfinder identifies subsidence centers but produces fragmented results. MCAS-TO improves boundary continuity but is constrained by a 2% area threshold, while the deep learning method achieves the highest boundary detection accuracy and captures ADAs expansion and merging processes. Spatially, the identified ADAs are mainly distributed in the central and southern parts of the mining area and are highly consistent with underground coal mining faces. Comprehensive analysis of the three ADA identification results reveals the spatiotemporal evolution of mining-induced deformation. The results demonstrate that mining activities are the dominant driving factor controlling the formation and evolution of ADAs. The findings can provide important technical support for geohazard prevention in loess mining areas. Full article

Given the severe water hazard in the coal seam roof of the Binchang mining area, existing research methods still primarily rely on traditional approaches such as empirical formula and numerical simulation—resulting in insufficient accuracy and convenience in predicting the height of the water-conducting fracture zone (WCFZ). By comprehensively considering three influencing factors—mining thickness, mining depth, and working face length—a data-driven approach was employed to construct a multiple nonlinear regression prediction model and a Convolutional Neural Network (CNN) prediction model based on 27 sets of measured data. Both models were subsequently applied to the ZF1403 and ZF1405 working faces in the Yadian coal mine. The results indicate that when considering only single factor of mining thickness, the coefficient of determination (R²) value of the multiple nonlinear regression model was 0.64. When considering all influencing factors, R² improved to 0.84. The mean absolute percentage error (MAPE) of multiple nonlinear regression model was 7.52%. The established CNN model achieved a R² of 0.97, a root mean square error (RMSE) of 9.78, and a MAPE of 4.67%. Compared to the Back Propagation Neural Network model, the prediction accuracy of the CNN model was significantly improved. The relative prediction errors of the developed height of WCFZ in the ZF1403 and ZF1405 working faces at Yadian mine were 6.30% and 2.54% for the multiple nonlinear regression model, respectively, and 0.97% and 3.15% for the CNN model, respectively. Both models met practical engineering requirements. This paper can provide reliable technical support for the prediction of water-conducting fracture zone height under mining conditions similar to the Binchang mining area. Full article

Sandstone of the Lower Cretaceous Luohe Formation is the main water inrush source in the Binchang Mining Area in the southwestern Ordos Basin. Its sedimentary environment and provenance features are critical for local coal development and safe mining. The Luohe Formation at Xiaozhuang Coal Mine comprises three vertical members: the lower member dominated by coarse- to medium-grained sandstones, the middle member mainly composed of fine-grained sandstones, and the upper member characterized by interbedded fine- to medium-grained sandstones and sandy conglomerates. This subdivision newly identifies a complete hydrodynamic evolutionary cycle of depositional environments from high-energy to low-energy and back to high-energy conditions. Integrated petrographic observations and analyses of major and rare earth elements first confirm that the tectonic affinity of the Luohe Formation progressively shifted from a passive continental margin to an active continental margin, accompanied by a corresponding transition in sediment provenance from the North China Craton to a magmatic arc source region. Trace element compositions precisely indicate that the Luohe Formation was deposited in a fluvial freshwater environment under hot, arid, and oxidizing conditions, thus providing new constraints on the paleoenvironmental evolution of the region. Full article

This study investigates the mining-induced overburden failure and the development law of the water-conducting fracture zone under key layer control during the extraction of an extra-thick coal seam (thickness ≥ 8 m) under extremely thick conglomerate strata (thickness ≥ 200 m) in the Zhaoxian Coal Mine, Binchang mining area, Shaanxi Province, China. A combined approach utilizing FLAC^3D numerical simulation and ground borehole full-section resistivity monitoring was adopted. The results indicate that the primary key layer (extremely thick conglomerate) and the sub-key layer (sandy mudstone) exert a significant inhibitory and segmented control effect on fracture development. The height of the water-conducting fracture zone increases in a “step-like” pattern with working face advancement, stabilizing at 270.3 m; the R_h/m is 23.5. The overburden failure morphology evolves dynamically through stages described as “funnel shape–concave shape–inverted trapezoid shape” as mining progresses. Field resistivity monitoring results (fracture zone height of 255 m, R_h/m of 22.17) show good agreement with numerical simulations, validating the control mechanism of key layers on overburden failure. These findings provide a theoretical basis for safe mining practices and water resource protection in extra-thick coal seams overlain by extremely thick conglomerate strata. Full article

Investigating the evolution mechanism of overlying strata fractures during mining and identifying the key factors that influence the development height of water-conducting fracture zones (WCFZs) are essential for preventing roof water inrush disasters, protecting mine water resources, and ensuring safe and sustainable mine development. To investigate the height of WCFZs and the evolution law of roof water inflow in a syncline structure working face under high-confined aquifer conditions, the 203 working face of Gaojiapu Coal Mine in Binchang Coalfield is selected as the engineering case. This paper analyzes the characteristics and control mechanisms of roof water inflow in a syncline structure mining area using UDEC 7.0 and COMSOL Multiphysics 6.0 multiphysics numerical simulation software. The results indicate that under different mining heights and advancing speeds, the height of the WCFZ in the overlying strata of a syncline structure working face continuously increases during the downward mining stage and in areas below the axis, and decreases thereafter, eventually stabilizing after reaching its maximum value at the initial stage of upward mining. When the WCFZ communicates with the strong aquifer of the Cretaceous Luohe Formation during the mining process, roof water inflow into the working face increases abruptly. The effectiveness of controlling water inflow by adjusting mining height is superior to that of controlling mining speed. Based on the response relationship between mining height, mining speed, and roof WCFZ, an on-site drainage prevention strategy was implemented involving reduced mining height and increased mining speed. Consequently, the roof water inflow at the working face has decreased from an initial rate of 950 m³/h to 360 m³/h. This study is of great significance for the safe and efficient extraction of coal seams under high-confined aquifers in the Binchang Coalfield, supporting the efficient development of coal resources while safeguarding regional water resources, thereby offering considerable engineering and practical value in promoting green mining and sustainable mining practices in large-scale coal production bases with similar geological conditions. Full article

Coal mine disaster safety monitoring often employs microseismic technology for its high sensitivity and real-time capability. However, nonlinear, non-stationary, and multi-scale signals limit traditional time series models (e.g., ARMA, ARIMA). This paper proposes a hybrid deep learning model—VMD-SE-CEEMDAN-BO-CNNGRU—integrating variational mode decomposition, sample entropy, CEEMDAN, Bayesian optimization, and a CNN-GRU architecture. Microseismic data from the 08 working face in D mine (Weibei mining area) were used to predict daily maximum energy, average energy, and frequency. The model achieved high predictive performance with R² values of 0.93, 0.89, and 0.88, significantly outperforming baseline models lacking modal decomposition. Comparative experiments verified the superiority of the VMD-first, SE-reconstruction, and CEEMDAN-second decomposition strategy, yielding up to 13% greater accuracy than reverse-order schemes. The model maintained R² above 0.80 on another dataset from the 03 working face in W mine (Binchang mining area), demonstrating robust generalization. Although performance declined during fault disturbances, accuracy for average energy and frequency rebounded post-disturbance, indicating strong adaptability. Overall, the VSCB-CNNGRU model enhances both accuracy and stability in microseismic prediction, supporting dynamic risk assessment and early warning in coal mining. Full article

The groundwater of the Luohe Formation in Binchang mining area is the main source of water for industrial and agricultural use and for drinking water for residents in the area. In order to study the hydrochemical characteristics and water-quality status of Luohe Formation groundwater in the mining area, statistical analysis, Piper three-line diagram, ion ratio relationship, and other methods were used to study the hydrochemical characteristics and formation factors of the groundwater. The Nemerow index evaluation method and the fuzzy comprehensive evaluation method based on principal component analysis were used to evaluate the groundwater quality in the mining area. The results show that the groundwater is weakly acidic as a whole, and the content of SO₄²⁻ and Cl⁻ have strong variability in terms of spatial distribution. The groundwater chemical type gradually evolves from SO₄ • HCO₃ • Cl–Na, SO₄–Na and SO₄ • Cl–Na-type water in the north of the mining area to SO₄ • HCO₃ • Cl–Na • Ca, HCO₃ • SO₄–Na • Mg, and SO₄ • Cl–Na • Ca • Mg-type water in the south. The formation of the hydrochemical composition of groundwater in the study area may be related to multiple factors such as cation-alternating adsorption, carbonate and sulfate dissolution, and hydraulic exchange with the groundwater of the upper Huachi Formation. Comparing the evaluation results of the Nemerow index method and the principal component analysis method, the latter’s evaluation results can take into account the contribution of each indicator to the overall groundwater quality, and to a certain extent can weaken the control effect of a certain pollution indicator, exceeding the limit on the entire evaluation result. Therefore, the evaluation results based on the principal component analysis method are more credible. Full article

There is a very thick water-bearing key strata above the coal seam in the Binchang mining area. When the mining scale is large, it easily breaks and leads to rockburst with a surge of water gushing in the panel. Adopting the layout pattern of a small panel and a large coal pillar can improve the stability of the main key strata, but at present, the research on the layout pattern of a small panel and a large coal pillar under extra-thick water-bearing key strata is still not perfect. Therefore, taking the second and third panels of a mine in Binchang as the engineering background, the width of the coal pillar and the mining scale of the panel are optimized by means of theoretical analysis, field measurement, and numerical simulation to prevent rockburst and control water inflow. The results show: (1) through theoretical calculation, it is deduced that the critical width of instability of the isolated coal pillar in the current mining scale is 257 m, and the critical mining scale of breaking and instability of the main key strata in the third panel is 537 m; (2) considering the bearing capacity of the isolated coal pillar and the recovery rate of coal resources, the reasonable width of the isolated coal pillar is 210~270 m, and when the width is 200 m and 250 m, the reasonable mining scale of the third panel is 490~550 m and 640~700 m, respectively; (3) the field practice shows that the actual width of the coal pillar between the second and third panels is less than the reasonable width, and the stress concentration in the isolated coal pillar area is relatively high, so the roof deep hole blasting and large-diameter drilling in coal seam are adopted to relieve pressure. After taking pressure relief measures, the stress concentration in the isolated coal pillar area is effectively reduced, and the pressure relief effect is remarkable. Full article

Water outbursts and rock bursts often occur during the mining of coal seams under water-rich sandstone strata with thicknesses exceeding 50 m, otherwise called ultrathick-and-hard strata (UTHS), which are common throughout the mining areas of northwestern China. It is important to understand the behaviors of their movement and the evolution of their internal fractures to inform the formulation of effective disaster prevention. Due to the presence of the Luohe Formation UTHS in the overburden of the Tingnan Coal Mine in the Binchang mining area and the powerful mining-induced pressure (MIP) events that occurred during the excavation of Panel #2, the internal strata movement of the overburden and the evolution of its fractures were monitored in situ by fiber optic and multipoint borehole extensometers (MPBX) during the excavation of Working Face #207. It was found that a large number of ring-shaped fractures were observed at 24.8–81 m above the lower boundary of the Luohe Formation—in areas above the goaf of Working Face #206—before Working Face #207 was mined. When Working Face #207 was mined, the fractures that were originally located in the deep strata of the Luohe Formation started to close and migrate towards shallow strata. Crack closure and migration were also observed during the monitoring of internal strata movement. Furthermore, the final displacements of Y1-1-1#, Y1-2-2#, and Y1-2-3# relative to the surface were 77, 248, and 134 mm, which were very small relative to the surface subsidence of 1380 mm. It was found that mining-induced perturbations caused the Luohe Formation UTHS to subside continuously and no risk of a large and sudden break would occur in the Luohe Formation UTHS during the mining of Working Face #207. The results of this study provide important data for the safety of mining operations at Working Face #207, which were validated by microseismic monitoring during the mining of it. Full article

Deep high static loading roadway is extremely prone to rock burst under dynamic load disturbance. The “force-energy criterion” for the failure of surrounding rock in such deep roadways and the “energy criterion” for the rock burst was established by considering the stress and energy evolution characteristics of rock burst under this circumstance. Under the engineering background of the main roadway in No.1 mining area of Gaojiapu Coal Mine in Binchang Mining Area, Shaanxi Province, China, the partial stress field and distortion energy field of surrounding rock in the main roadway and the spatial-temporal evolution laws under dynamic load disturbance were simulated and analyzed by using a built-in dynamic module of FLAC^3D. Results show that after the dynamic load disturbance, the partial stress and distortion energy are concentrated in the shallow part at two walls of the roadway in the early phase. With the continuous propagation of dynamic load stress wave, the partial stress and distortion energy are transferred to the deep part. The sudden high-energy release occurred in the peak zone of partial stress, leading to the plastic failure of coal and rock mass. Subsequently, the distortion energy was fully accumulated in the original plastic zone and transferred from shallow surrounding rocks to the deep surrounding rocks in the roadway, where the partial stress and distortion energy of coal and rock mass reached the yield conditions. Thus, the original plastic zone was sharply expanded, thereby forming a new plastic zone. The coal and rock mass experienced an approximately static failure when no residual energy (ΔU) was found in it. When ΔU > 0, the rock mass experienced dynamic failure, and ΔU was mainly the volume transformation energy, which is approximately one-half of the total elastic strain energy. ΔU was transformed into the initial kinetic energy of broken coal and rock mass. Thus, the coal and rock mass are burst out. In severe cases, this condition was manifested by the rock burst in the main roadway. An optimization scheme of prevention and control measures for rock burst was proposed on the basis of the above conclusions. The microseismic activity laws before and after the unloading were compared, and a good effect was achieved. The research results can lay a theoretical foundation for predicting and preventing rock bursts in coal mines by actively regulating the disaster-pregnant environment and mitigating the disaster-inducing conditions. Full article