The study looked at why lower coal seams become unstable when nearby coal seams are mined repeatedly. Researchers tested coal strength and simulated mining scenarios to understand how roof structures and cracks affect coal face stability. They found that mining caused more cracks in the coal face, making it weaker and prone to failure. When mining the 17# coal seam, different roof structures increased pressure on the coal face, leading to instability. The main reason for coal face failure was the weak coal body, often resulting in soft coal shear failure. This research gives insights into coal face instability in similar conditions.