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In view of the problem of floor water inrush in the process of deep coal seam mining, propose to establish a risk assessment model for coal seam floor water inrush using GIS and combined weight TOPSIS method. Take coal 12-1 of level −950 in Donghuantuo Coal Mine as an example, the coal seam hosting thickness, coal seam burial depth, fault intensity index, aquifer thickness, water-rich aquifer thickness, first aquiclude thickness and second aquiclude thickness are taken as decisive indexes. Based on actual engineering exploration, the entropy weighted AHP weighted TOPSIS method is used to determine the partition threshold and classification level, analyse the risk of water inrush from coal seam floor, and visualise it based on GIS platform. The results show that the combined weight values of coal seam burial depth and fault scale index are 0.4008 and 0.2201, which have a significant impact on water inrush from the coal seam floor. The zoning threshold for the risk coefficient of water inrush from the 12–1 coal seam floor is 0.478, The overall water inrush risk of the mine field is less. Only a few areas in the southwest of the mine field are water inrush risk areas.

Roof water inrush at the mine face and shortages of water resources are both problems in the karst mining area in southwestern China. In this study, field measurements, similar simulations, and theoretical analysis were conducted, a physical model of upward and downward mining in a test mine was constructed, and the dynamic evolution of water inrush and the mechanism of water inrush in karst roofs under different mining sequences were analysed. As a result, the problem of water inrush at the mine face was solved, and a method to utilize the karst groundwater water resources was proposed. The research showed that after downward mining, the maximum development height of the water-conducting fracture in coal seam 4 was 43.1 m, and the fracture mining ratio was 14.4. A water-inrush pathway formed at the connection between the mining-induced fractures and the roof karst aquifers, and the safe mining of coal seams 4 and 9 were threatened by water inrush from the goaf. So, the feasibility of upward mining was determined by the ratio test and \"three zones\" discrimination methods, and the evolution of water-inrush pathways during upward and downward-inclined mining were compared. Upward-inclined mining was proposed to control roof water inrush. Moreover, the quality of the water flowing into the goaf was compared with the Chinese standards for water use, and the water in the goaf of the lower coal group was suitable for water resource utilization. This research provides a basis for preventing and controlling roof water inrush disasters and for appropriate utilization of water resources in these mining areas.

The mechanism of water inrush from the stope floor has always been the key and difficult point in the research field of coal mine water disaster prevention and control. The mechanical essence of water inrush from the mining floor is the loading–unloading stress state transformation process. To reveal the joint action mechanism of principal stress state transformation and water pressure in the process of water inrush from the stope floor, the author studied the water inrush criterion, the characteristics of saturated rock damage test and the characteristics of principal stress transformation of coal floor using theoretical analysis, laboratory test and numerical calculation. Research results: The results show that the threshold of water inrush criterion of the mining floor is 1, based on the discrimination index of disturbance degree of mining floor strata, the threshold of floor cracking pressure, and the instability index of floor aquifer. The damage to the limestone floor samples has an obvious delay effect after pressure relief, but it produces a stress drop phenomenon when it is unstable. The maximum principal stress of the back floor in front of the working face is converted from horizontal stress to vertical stress. After the floor is unloaded, the maximum principal stress is transformed from vertical stress to horizontal stress. The difference between the maximum principal stress and the minimum principal stress of the mining floor presents different distribution characteristics at different depths, but it increases overall and is concentrated near the front and back coal walls of the working face. The research results will help to further reveal the mechanism of water inrush from the stope floor.

Frequent water inrush disasters in deep coal seam mining pose a significant threat to the safety of coal extraction operations. Due to the complexity and non-linearity of water inrush factors, evaluating the risk of water inrush in coal seam floor is challenging and the results can vary significantly. To achieve more accurate evaluations, the weighted rank-sum method and Grey-TOPSIS method were employed, alongside a master control indicator variable-weight model, for assessing the risk of water inrush in coal seam floor. Validation of the evaluation zoning map against actual conditions revealed that both methods produced accurate assessment results, thus affirming the reliability of the new evaluation approach. Compared with the water inrush coefficient method, the diversification of index factors weakened the absolute control effect of the water inrush threshold. The evaluation outcomes were more systematic and comprehensive, providing a new methodology and perspective for deep coal seam mining.

For water inrush from coal floor, due to different kinds of controlling factors and their internal correlations, the accuracy of prediction model is mostly below expectation. In this paper, it studies on which controlling factors should be selected for water inrush prediction model because all these factors have different influence on water inrush incidents based on the analysis of in situ data. Some factors are proved having limited impacts on water inrush, it is no necessary to collect in situ data of those factors from coal mining work face. Therefore, the workload and expense will decrease. In this paper, an index system of factors influencing water inrush from coal floor is established based on the current water inrush controlling theory and detailed analysis of in situ data obtained from mining regions. Following the Wrapper method in feature selection, 10 main controlling factors were selected from 14 existing indicators which were thought could affect water inrush. After training on dynamic GRU model which is made for water inrush prediction, a comparison among dynamic GRU model and stable SVM and BPMN models turns out the advantages of the previous with a higher accuracy in train, validation and test set against the latter. It is believed GRU model is able to predict water inrush water inrush from coal floor with high accuracy and hence enhances mining safety.

We analyzed the regional nature of China’s coal mine water disasters based on three aspects: the main water source, water-conducting passages, and threat level of water hazards. The development of water hazard control technology in China’s coal mines, including exploration and assessment of hydrogeological conditions, water inrush mechanisms, and predictive technology were all reviewed. We then focused our discussion on the calculation theory and methods behind mine inflow prediction, methods of dewatering and depressurizing, and technology for mining under water pressure and water-blocking grouting. Finally, we present the evolving trend of coal mine water disaster prevention and control technology, which is characterized by accuracy, transparency, environmental considerations, informatization, and intelligent technology.

The hydrogeological conditions of the Qianbei coalfield are complex, and karst water in the roof rock frequently disrupts mining operations, leading to frequent water inrush incidents. Taking the representative Longfeng Coal Mine as a case study, research was conducted on the development pattern of the water-conducting fracture zone and the water inrush mechanisms beneath karst aquifers. On the basis of key stratum theory and calculations of the stratum stretching rate, the karst aquifer in the Changxing Formation was identified as the primary key stratum. It was deduced that the water-conducting fracture zone would develop into the karst aquifer, indicating a risk of roof water inrush at the working face. Numerical simulations were used to study the stress field, displacement field, and plastic zone distribution patterns in the overlying roof strata. Combined with similar simulation tests and digital speckle experiments, the spatiotemporal evolution characteristics of the water-conducting fracture zone were investigated. During the coal mining process, the water-conducting fracture zone will exhibit a \"step-type\" development characteristic, with the fracture morphology evolving from vertical to horizontal. Near the goaf boundary, the strain gradually decreases, and the instability of the primary key stratum significantly impacts the mining space below, leading to the closure of interlayer voids or the redistribution of water-conducting fissure patterns. Field measurements of the water-conducting fracture zone reveal that postmining roof fractures can be classified into tensile-shear, throughgoing, and discrete types, with decreasing water-conducting capacity in that order, the measured development height of the water-conducting fracture zone (51 m) aligns closely with the theoretical height (51.37 m) and the numerical simulation height (49.17 m). Finally, from the perspective of key stratum instability, the disaster mechanisms of dynamic water inrush and hydrostatic pressure water inrush beneath the karst aquifers in the northern Guizhou coalfield were revealed. The findings provide valuable insights for water prevention and control efforts in the Qianbei coalfield mining area.

The risk assessment of water inrush from mining floors above confined aquifers has important theoretical and practical significance for safe mining operations and sustainability. At present, the risk assessment methods of water inrush from the floor are mostly based on the mathematical assessment theory which lacks physical process information that can reflect the mechanism of floor water inrush. Therefore, in this study, a new analytical solution method for assessing water inrush risk from the inclined mining floor of a coal seam above a confined aquifer is proposed. First, considering the factors of mine pressure, confined water pressure, and coal seam dip angle, a mechanical and analytical model of the stress distribution in the mining floor along the inclination of a coalface is established. Subsequently, the failure characteristics of the inclined mining floor along the inclination of the coalface are investigated using the Mohr–Coulomb criterion and on-site measurement. Then, a criterion to determine the location of the effective water-resisting layer and the water inrush from the inclined mining floor is deduced based on the thin plate theory, and applied for the risk assessment of water inrush in the 330301# coalface. Finally, considering the failure characteristics of the mining floor along the coalface’s strike, the spatial characteristics of the failure of the inclined mining floor are analyzed. Furthermore, the influence of the coal seam’s dip angle on the water inrush position from the floor is discussed.

To obtain the seepage evolution rule and water inrush mechanism of the collapse column, a multi-field coupled mechanical model for water inrush disasters caused by the collapse column is established in this paper, on the basis of the specific engineering conditions of the 1908 working face in the Qianjin coal mine. The mechanical model is composed of internal column elements within the collapse column and surrounding rock masses. The research focuses on the seepage evolution rule in the roof collapse column under different mining conditions and investigates the permeation instability mechanism of collapse column based on the transition of flow state. The research results indicate that the seepage pathway evolves continuously, ultimately forming a channel for water inrush, as the working face advances towards the collapse column. Besides, the water inflow increases rapidly when the working face advances 100 m, then gradually stabilizes, indicating that the seepage channel entry of the collapse column is in a stable stage. Meanwhile, mass loss in the collapse column gradually moves upward. the collapse column remains stable as a whole in the initial stage of water flow, with a small permeability, exhibiting linear flow. As time steps increases, particle loss in collapse column gradually extends to the upper part, forming a stable seepage channel. The flow velocity shows fluctuations with a slow declining trend over time.

Roof water inrush in coal mining is a significant type of water-related disaster that usually results from the interconnection of water-bearing geological formations formed by cracks during and after work face mining. Therefore, monitoring roof water infiltration is of paramount importance in preventing or mitigating water inrush in the mine work face. This study employed the roof borehole electrical resistivity tomography method to conduct physical experiments for monitoring water seepage in roof cracks generated during coal model mining. Additionally, roof water infiltration monitoring was performed in the 7130 work face of the Qidong Coal Mine. The results of both physical experiments and field tests demonstrate that roof borehole electrical resistivity tomography (ERT) is well suited for monitoring roof water infiltration in mine work faces, enabling the determination of the temporal and spatial distributions of water seepage. By analyzing the variation patterns of low-resistivity anomalies in the resistivity profile, the water-conducting channels and water outflow points can be identified. Experiments and field tests suggest that the resistivity and its changes are related to the amount of water inflow and water channel. With the increase of water inflow, the relatively low resistivity anomalies region increases, the resistivity value decreases and the water channel appears and expands. With the amount of water inflow decreasing, the relatively low resistivity area becomes smaller, the resistivity value increases, and the water channel narrows or even disappears.Furthermore, by combining the areas of low-resistivity anomalies, a qualitative assessment of the water content can be achieved. Finally, The results of the periodic weighting analysis of the field tests indicate that roof water infiltration is related to periodic weighting. The greater the periodic weighting is, the more severe the roof water infiltration.