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High-intensity coal mining activities in China's western mining area are damaging fragile ecological environments. The key to coordinating ecological protection and coal mining is to understand the law of overlying strata migration in high-intensity mining. However, it is difficult for conventional monitoring methods to efficiently monitor overburden movement in high-intensity mining areas in real time. In this paper, a space-sky-surface (3S) integrated system is proposed to conquer this challenge. This monitoring system consists of three parts: a space monitoring component (a combination of a global navigation satellite system (GNSS) and interferometric synthetic aperture radar (InSAR)), a sky observation component (an unmanned aerial vehicle (UAV) equipped with a measuring camera (MC)), and a surface exploration component (ground-penetrating radar (GPR) and high-density electricity method (HDEM)). This system was successfully applied to the 12,401 longwall face in the Shangwan coal mine (the maximum mining height is 8.8 m). The deformation cloud map of the entire mining area was obtained through InSAR monitoring technology accompanying the 3D laser scanning to improve the accuracy in the local region of 12,401 longwall face. The distribution characteristics and dynamic evolution of surface fractures were obtained using UAV and MC (visible light camera + infrared camera). Using the HDEM and GPR technologies, the fracture development was well detected. Based on the strata movement theory, combined with the monitoring results, a three-dimensional model of overburden rock fracture after 12,401 longwall face mining was constructed. Monitoring results and the fracture model provide a basis for controlling air leakage in the goaf and remediation of surface fracture. [ABSTRACT FROM AUTHOR]

This study investigated the development and formation of ground fissures at panel 12,401 of the Shangwan Colliery in the Shendong mining area, characterized by the current largest mining height and an aeolian sand surface in China. An integrated monitoring method was employed to examine the ground subsidence, distribution and development pattern of ground fissures, and the relationship between fissure width and depth, including an unmanned aerial vehicle, ground penetrating radar, and real-time kinematic and manual measurements. Then, the development and formation mechanisms of ground fissures were elucidated through theoretical analysis and physical simulation. The results indicate that ultra large mining height longwall panel extraction causes a greater ground subsidence and horizontal deformation than those of the conventions, resulting in more severe damage in the permanent margin area. The ratio of burial depth to mining height (H/M) decreases to less than 30 due to the ultra large mining height, and deep-burial panel displays the characteristics of shallow coal seam mining, such as "step subsidence". The sliding instability of the primary key stratum causes the simultaneous cutting-off of the aeolian sand layer to form step-like ground fissures. The cause of the tensile fissures is the horizontal surface deformation exceeding the deformation threshold of the aeolian sand layer, and the dynamic tensile fissures were self-restored in 2 weeks as the panel advanced. Step-like fissures connected the working face with the ground, but the depth of the tensile fissures was less than 5.0 m and increased linearly with the fissure width. [ABSTRACT FROM AUTHOR]