scholarly journals Research on dynamic prediction model of surface subsidence in mining areas with thick unconsolidated layers

2021 ◽  
pp. 014459872098164
Author(s):  
Shenshen Chi ◽  
Lei Wang ◽  
Xuexiang Yu ◽  
Weicai Lv ◽  
Xinjian Fang
Keyword(s):  
Prediction Model ◽  
Mining Area ◽  
Influence Coefficient ◽  
Exponential Form ◽  
Dynamic Prediction ◽  
Mining Areas ◽  
Subsidence Basin ◽  
Subsidence Prediction ◽  
Working Face ◽  
Surface Dynamic

In order to improve the accuracy of the surface dynamic prediction model in mining areas with thick unconsolidated layers and improve Knothe time function, the influence coefficient was firstly changed into the coefficient in exponential form, and the influence coefficient of unconsolidated layer was added. Then, a subsidence basin prediction model for mining under thick unconsolidated layers was established. Next, the model was combined with the improved Knothe function, thus constructing a new mining subsidence prediction model. The new subsidence prediction model was applied in 1414 (1) working face in Huainan mining area. The results showed that the integrated model could better reflect the subsidence process, and the prediction values and the measured values agreed well.

scholarly journals Study on the mechanism of water inrush in the arid western mining area

2019 ◽  
Vol 118 ◽  
pp. 03008
Author(s):  
Chao Zheng ◽  
Lan Yu ◽  
Jiangyi He ◽  
Fengfeng Yang ◽  
Jufeng Zhang
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Water Inrush ◽  
Hydrodynamic Pressure ◽  
Mining Area ◽  
Mining Areas ◽  
Isolation Layer ◽  
Working Face ◽  
Combined Action ◽  
Tension Fracture

The analysis found that the coal mining process in the western mining area has the mining loss and disaster effect of the water-rich aquifer of the coal seam roof, which is mainly manifested by the overburden water in the roof. On this basis, the formation and development of the separation water of the roof is proposed, and the mechanism of the water inrush from the layer is revealed. It is found that there is hydrostatic pressure and hydrodynamic pressure in the separated water, under the combined action of bed separation water pressure, the mining-induced fracture and water-isolation layer tension fracture are connected, which causes water inrushing in the coal working face of the mine, and provides a theoretical guarantee for the large-scale development of coal resources in western mining areas.

Surface dynamic subsidence prediction model of solid backfill mining

2016 ◽  
Vol 75 (12) ◽  
Author(s):  
Xiaojun Zhu ◽  
Guangli Guo ◽  
Jianfeng Zha ◽  
Tao Chen ◽  
Qi Fang ◽  
...  
Keyword(s):  
Prediction Model ◽  
Subsidence Prediction ◽  
Backfill Mining ◽  
Solid Backfill Mining ◽  
Surface Dynamic ◽  
Dynamic Subsidence

scholarly journals Height prediction of water-flowing fracture zone with a genetic-algorithm support-vector-machine method

2020 ◽  
Vol 7 (4) ◽  
pp. 740-751
Author(s):  
Enke Hou ◽  
Qiang Wen ◽  
Zhenni Ye ◽  
Wei Chen ◽  
Jiangbo Wei
Keyword(s):  
Genetic Algorithm ◽  
Support Vector Machine ◽  
Prediction Model ◽  
Mining Area ◽  
Support Vector ◽  
Burial Depth ◽  
Machine Method ◽  
Working Face ◽  
Face Length ◽  
Coal Seam Thickness

AbstractPrediction of the height of a water-flowing fracture zone (WFFZ) is the foundation for evaluating water bursting conditions on roof coal. By taking the Binchang mining area as the study area and conducting an in-depth study of the influence of coal seam thickness, burial depth, working face length, and roof category on the height of a WFFZ, we proposed that the proportion of hard rock in different roof ranges should be used to characterise the influence of roof category on WFFZ height. Based on data of WFFZ height and its influence index obtained from field observations, a prediction model is established for WFFZ height using a combination of a genetic algorithm and a support-vector machine. The reliability and superiority of the prediction model were verified by a comparative study and an engineering application. The results show that the main factors affecting WFFZ height in the study area are coal seam thickness, burial depth, working face length, and roof category. Compared with multiple-linear-regression and back-propagation neural-network approaches, the height-prediction model of the WFFZ based on a genetic-algorithm support-vector-machine method has higher training and prediction accuracy and is more suitable for WFFZ prediction in the mining area.

scholarly journals On Time-Series InSAR by SA-SVR Algorithm: Prediction and Analysis of Mining Subsidence

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yun Shi ◽  
Qianwen Li ◽  
Xin Meng ◽  
Tongkang Zhang ◽  
Jingjian Shi
Keyword(s):  
Prediction Model ◽  
Prediction Models ◽  
Underground Mining ◽  
Mining Area ◽  
Mining Subsidence ◽  
Coefficient Of Determination ◽  
Support Vector ◽  
Subsidence Prediction ◽  
Small Baseline ◽  
Sbas Insar

Given the increasingly serious geological disasters caused by underground mining in the Hancheng mining area in China and the existing problems with mining subsidence prediction models, this article uses the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technology to process 109 Sentinel-1A images of this mining area from December 2015 to February 2020. The results show that there are three subsidences: one in Donganshang, one in south of Zhuyuan village, and one in Shandizhaizi village. In the basin, the maximum annual average subsidence rate is 300 mm/a, and the maximum cumulative subsidence is 1000 mm. The SBAS-InSAR results are compared with Global Positioning System (GPS) observation results, and the correlation coefficient is 74%. Finally, a simulated annealing (SA) algorithm is used to estimate the optimal parameters of a support vector regression (SVR) prediction model, which is applied for mining subsidence prediction. The prediction results are compared with the results of SVR and the GM (1, 1). The minimum value of the coefficient of determination for prediction with SA-SVR model is 0.57, which is significantly better than that those of the other two prediction methods. The results indicate that the proposed prediction model offers high subsidence prediction accuracy and fully meets the requirements of engineering applications.

scholarly journals Ground Fracture Development and Surface Fracture Evolution in N00 Method Shallowly Buried Thick Coal Seam Mining in an Arid Windy and Sandy Area: A Case Study of the Ningtiaota Mine (China)

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7712
Author(s):  
Yaokun Fu ◽  
Jianxuan Shang ◽  
Zhenqi Hu ◽  
Pengyu Li ◽  
Kun Yang ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Mining Area ◽  
Ground Subsidence ◽  
Deformation Pattern ◽  
Self Healing ◽  
Thick Coal Seam ◽  
Mining Areas ◽  
Working Face ◽  
Fracture Development ◽  
Seam Mining

An observatory was established at the Ningtiaota Mine (China) in order to investigate the surface deformation pattern of N00 method workings mining in shallow buried thick coal seams in a windy-sand area. The observatory allows one to measure the coupling between the periodic changes of parameters related to ground subsidence and ground cracks with workings advancement. The data monitored in the field indicate that when the adjacent mining workings are mined below the ground, a sinkhole basin with a larger impact area will be formed. New ground fractures are formed above the mining area to connect with the fractures above the mining face. As a consequence a new pattern of “O” circle distribution beyond the working face is formed, which develops rapidly during the working face recovery. In addition, the dynamic fractures in coal mining are characterized by the phenomenon of self-healing. Our findings will help to protect the surface environment of the mine area during shallow buried high-intensity mining activities in the Lime Tower coal mine, and are also an important guideline in other windy beach mining areas.

scholarly journals Borehole-Based Monitoring of Mining-Induced Movement in Ultrathick-and-Hard Sandstone Strata of the Luohe Formation

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1157
Author(s):  
Xiaozhen Wang ◽  
Weibing Zhu ◽  
Jianlin Xie ◽  
Hongkai Han ◽  
Jingmin Xu ◽  
...  
Keyword(s):  
Lower Boundary ◽  
Mining Area ◽  
Microseismic Monitoring ◽  
Mining Operations ◽  
Strata Movement ◽  
Mining Areas ◽  
Working Face ◽  
And Migration ◽  
Shallow Strata ◽  
Deep Strata

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.

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