In order to ensure the safe mining of Carboniferous-Permian No.9 coal seam in Jinggezhuang mining area, according to the collected data (Jinggezhuang geological report, Jinggezhuang hydrogeological map, Jinggezhuang No.9 coal seam mining plan, etc.). ), the water inrush probability of each evaluation unit is calculated by using the method of combining GIS and BN, and on this basis, the water inrush risk of coal seam roof in the study area is evaluated. Finally, corresponding prevention measures are put forward for different water inrush probability areas. The specific research contents are as follows:
(1) The coupling technology of GIS and BN is studied, and the feasibility of its application in water inrush from coal seam roof is analyzed.
(2) Establish the basic theoretical system of risk assessment of water inrush from coal seam roof.
(3) By analyzing the main influencing factors of water inrush from coal seam roof, the evaluation index system of water inrush from coal seam roof is established, including geological structure characteristics, aquifer conditions, aquifuge conditions and mining activities.
(4) Using the data collection function and spatial analysis function of GIS, the relevant data collected are quantified, and the thematic map of each evaluation index is established, and the spatial database is also established. On this basis, the sub-thematic maps are superimposed and analyzed, and an evaluation unit is established to generate a multi-attribute joint spatial database.
(5) Based on the database, BN model of water inrush from coal seam roof is established by BN software, and the model is explained and analyzed. Finally, the probability of water inrush in each evaluation unit is calculated by BN reasoning, and the risk evaluation map of water inrush in coal seam roof is obtained on this basis.
(6) Submit the final results and analyze the results, and put forward corresponding prevention measures.
9.2.2 Technical route
The research object of this paper is the regional risk assessment of roof water inrush in Jinggezhuang coal seam. The purpose is to determine which areas are prone to water inrush and the possibility of water inrush through the analysis of the basic conditions and induced dynamics of water inrush from coal seam roof. The research method is mainly based on geological factors and mining factors, using quantitative mathematical methods such as mathematical statistics and artificial intelligence, combined with the investigation results of water inrush in Jinggezhuang coal seam, to determine the possibility of water inrush from coal seam roof in different positions in the research area, and finally explore a feasible way to evaluate the risk of water inrush in mines. The specific research route is shown in Figure 9. 1.
(1) data collection: collect the data of physical geography, geology, hydrogeology, drilling and other related aspects in the study area, and sort them out according to the requirements of roof risk assessment;
(2) Construction of evaluation index system: analyze and determine the control factors of water inrush from coal seam roof in detail and systematically, and correctly establish the evaluation index system of water inrush from coal seam roof;
(3) Establishment of thematic map of evaluation index: on the basis of analyzing and determining the factors of water inrush from coal seam roof, taking the statistical analysis function of spatial data of GIS as the operating platform, and using its powerful spatial information processing and analysis ability, various graphic information is quantified, and sub-thematic maps of various evaluation factors of water inrush from coal seam roof are established;
Figure 9. 1 technology roadmap
(4) Multi-factor superposition analysis to determine the evaluation unit: apply the spatial analysis function of GIS to carry out the composite superposition of multi-source geological information, realize the superposition of different information in the same area with unified geographical coordinates, determine the evaluation unit of the study area, and generate the spatial attribute database at the same time;
(5) BN establishment: based on the spatial attribute database, using Genie software and BN related knowledge, BN diagrams of water inrush factors and water inrush events are established;
(6) BN analysis: Through BN analysis, the most favorable factor state combination of water inrush is obtained;
(7) BN reasoning: In the C# development environment, add the SmileX component provided by Genie to the program, realize the data interface between Genie and GIS, and complete probability calculation and BN probability reasoning;
(8) Evaluation zoning: according to the above probability calculation results, using the display function of GIS, the risk degree of water inrush from coal seam roof is displayed by zoning, and the risk evaluation map of water inrush from coal seam roof is obtained;
(9) The sample dichotomy is used to verify the evaluation model, which proves the feasibility of the evaluation method.