Monitoring and Forecasting of Surface Deformation at Victoria and Cantacuzino Mines

The underground mining of the rock salt deposit from Slănic started in 1665, with the Old Mines and continued in 1970, with Victoria Mine, then in 1993, with Cantacuzino Mine. The mining method applied at Victoria and Cantacuzino mines was the one with small rooms and square pillars, with which over 9.7 million m3 of rock salt were extracted. This very large volume of underground mining voids led to the convergence of the underground excavations and thus to the deformation of the surface. This article presents the analysis of the measurements of surface displacement and the prediction of its subsidence over time. Also, the main factors that contributed to the deformation of the surface are analyzed, namely: the dimensions of the underground voids, the mining depth, the geomechanical characteristics, the tectonics and microtectonics of the deposit, the hydrogeology and the effect of blasting.