Prediction of Surface Subsidence Extension due to Underground Caving: A Case Study of Hemushan Iron Mine in China

Figure 6

Variation of the ground surface in the Hemushan Iron Mine observed by the Google Earth satellite images. (a) Original ground surface without surface subsidence, observed on September 6, 2007. The boundary represents the projection of the iron deposit on the ground surface. (b) Surface subsidence observed on October 19, 2011. Backfill is implemented in the caved space with waste rock. (c) Surface subsidence observed on October 11, 2014. The slip failure above the free surface of the caved materials has been observed in the area north of the caved space. (d) Surface subsidence observed on October 25, 2017. No large-scale extension of the surface subsidence is observed around the caved space, and the construction projects maintain safe working conditions during the mining process.