The study looked at how the ground above a coal mine in Inner Mongolia moves when the coal is being extracted. They found that the layers of rock above the coal face can break and slide, causing different spaces to form as the coal is mined. The researchers used a mix of theory and on-site observations to understand how the ground behaves during mining. They discovered that the main layer of rock above the coal face can collapse after the layer below it breaks, leading to unstable conditions. This information helps miners understand how the ground moves and changes during coal extraction in deep seams.