## 1 Introduction
[PERSON] and colleagues [14] established two models of multivariate nonlinear regression and GA-BP neural network based on field-measured data and analyzed that mining thickness and inclined length of working face are the main controlling factors affecting the development height of water-conducting fractures. [PERSON] [15] revealed that the development height of water-flowing fracture is related to the thickness of coal seam mining through the combination of theoretical analysis and experiment. [PERSON] and colleagues [16] used stratum monitoring technology to monitor the study area and obtained that the longwall mining method can effectively control the development height of a water-flowing fracture; [PERSON] et al. [17] used the borehole television method to study the temporal and spatial evolution law of the water-conducting fractures generated during the mining process from the coal seam to the surface and obtained the multiple relationship between the development height of the water-conducting fractures and the mining height. [PERSON] and colleagues [18] analyzed the influence of mining thickness and working width on the development height of water-flowing fracture and constructed a three-dimensional structure model of the development height of water-flowing fracture to visualize the spatial distribution of water-flowing fracture. [PERSON] and others [19] obtained that the development height of water-conducting fractures is proportional to the mining thickness by means of field measurement, indoor simulation, and theoretical analysis. With the development of a large number of monitoring works on the development of water-conducting fractures in coal seam overburden and the in-depth analysis of the measured data of the maximum development height, it is found that the development degree of water-conducting fractures in coal seam overburden will be completely different under the same mining factors and different geological factors. Therefore, the study of the influence of geological factors on the development of water-conducting fractures in overlying strata of coal seams has gradually become a research hotspot. At present, the relevant research results mainly focus on mining depth, faults, key strata, loose strata, the physical and mechanical properties of overlying strata, and so on. [PERSON] and colleagues [20] believed that the mining depth is also the main controlling factor of the development height of water-conducting fractures; especially in the shallow coal seam mining area, it is not appropriate to use the \"mining height multiple\" to predict the height of water-conducting fractures. [PERSON] and colleagues [21] used a similar material simulation test method to study the influence of small faults on the development height of mining-induced fractures in overlying strata and obtained that normal faults would increase the development height of water-conducting fractures, while reverse faults had little effect on the development height of water-conducting fractures. [PERSON] et al. [22] established the mechanical model of the arch structure in the loose layer and deduced that the arch structure of the loose clay layer can effectively block the development of the water-conducting fracture zone and the formation mechanism of the arch structure. [PERSON] and colleagues [23] used numerical simulation software to study the influence of thick sandstone on the development characteristics and laws of water-conducting fractures and concluded that the position of thick sandstone is the main factor affecting the development height of water-conducting fractures. Based on the key stratum theory, [PERSON] and colleagues [24; 25] analyzed the influence of different key stratum positions on the development height of water-flowing fracture and determined the relationship between the critical height of the key stratum fracture and the mining height.