Recently, the “Repairable Underground Permanent Sealing Wall” developed by China Shenhua’s Chahasu Coal Mine was granted a national invention patent. The technology successfully addresses the common industry challenge in which conventional underground sealing walls are prone to cracking and air leakage under mining-induced stress disturbance, providing key technical support for safety management and control of coal mine goafs.
To tackle the prominent problem of permanent sealing walls developing hidden fissures under rock pressure and surrounding rock effects, which can lead to sealing failure and threaten goaf safety, the invention provides an innovative sealing device integrating fissure detection, automatic repair, and condition monitoring. The device uses a double-wall structure with a filler body in between, fastened as a whole by multiple sets of anchors, improving deformation resistance and structural stability while effectively reducing wall damage caused by stress concentration. Equipped with dedicated detection and repair components, the system can quickly identify wall fissures through water-pressure tests. Once damage is detected, it automatically switches the grouting pipeline and injects fly ash slurry or expansive mortar for precise sealing. A venting device ensures the slurry fully fills fine fissures. An intelligent monitoring module is also incorporated to monitor wall condition in real time through image recognition, automatically issue warnings, and coordinate pipeline switching and remote handling, enabling early detection of hidden hazards and rapid crack repair, and eliminating repeated manual on-site inspections.
The patent enhances the reliability of sealing walls, mitigating safety risks including gas emission and spontaneous combustion within goafs, while reducing repeated maintenance and lowering operation and maintenance costs. It delivers notable safety and economic benefits and has important practical value for advancing the upgrading of coal mine ventilation safety technology and equipment and ensuring mine work safety.
