Tongling Maodi Mining Co., Ltd operates a limestone mine with mining area of 0.1075 square kilometers. A landslide geological disaster occurred at the mine on September 26, 2023. The landslide occurred at the top of the outer slope of the treatment area on the south side of the project area. The main manifestation was the collapse of the loose Quaternary soil at the top of the open-pit slope at the front edge of the slope. The collapsed material accumulated to the +250m platform and the slope surface. Many tensile cracks appeared on the slope surface and the rear edge. Below the slope were the open-pit mining terraces and slope surface. The collapsed material was mainly Quaternary residual slope deposits, with lithology including gravelly silty clay and gravelly soil. In November of the same year, the mine carried out slope cutting treatment on the landslide slope. In early January 2024, some soil in the slope-cutting treatment area collapsed again. The potential landslide body is located at the top of the mining area and is a high-level landslide. Once it becomes unstable and slides down rapidly, the resulting air waves and flying rocks may pose a threat to workers and transport vehicles far below. At the same time, the slope of the western transport road is at risk of instability under natural and rainstorm conditions. To ensure mining safety, it is necessary to implement automated monitoring of the southern and western slopes.

15 GNSS devices, 1 visual deformation meter, 5 crack gauges, 12 multi-functional monitoring instruments, 4 deep inclinometers, 3 water level gauges, 3 blasting vibration meters, 6 earth pressure gauges, 1 rain gauge, 3 early warning broadcast systems, and 1 video surveillance system were deployed on the south and west slopes to achieve long-term, all-round, and multi-factor real-time online monitoring of the open-pit mine slopes. Simultaneously, a monitoring and early warning platform was constructed to enable real-time access, intelligent analysis, visualization, and early warning information processing of monitoring data.

On January 31, 2024, monitoring devices G07, G08, G11, G13, G14, LF04, and LF05 issued red alarms. Our personnel conducted an on-site inspection and found significant deformation in the intercepting ditch in the landslide area on the south side. A 10cm wide through-crack appeared on the upper part of the +270 platform along the LF03 and LF04 axes. After on-site confirmation, the mine management activated the emergency plan, carried out an emergency evacuation, and continuously alerted passing personnel and vehicles via on-site warning broadcasts. On February 2, 2025, a remote high-altitude landslide occurred on the south slope, burying the factory buildings below. Due to timely evacuation, loss of life and significant property damage were avoided.