The presented work deals with the problem of terrain surface and rock mass deformation in the area of the Bochnia Salt Mine. The deformations are related to natural causes (mainly the tectonic stress of the Carpathian orogen) as well as anthropogenic ones related to the past mining activity conducted directly under the buildings of the town of Bochnia. The discussed characteristics of land surface deformation are important from the point of view of threats to surface features and contribute to spatial development. Particularly anomalous zones of observed subsidence basins are examined as places of second order deformation effects. The author presents a method of determinations of these anomalous areas and he discusses their origins.
Area of Inowrocław town is considered as tectonically active due to halotectonic movement of salt dipair situated there. The geodetic surveys carried out for the determination of terrain surface deformations over the years revealed characteristics of the movement. The evaluated vertical displacements based on measurements of benchmarks show different characteristics, depending on distant points assumed as reference benchmarks. This raises problems in analysis, interpretation of the results and decision makings in master planning. The authors demonstrate a method of adjustment calculations that minimize the inconsistencies between previously elaborated heights and inconsistencies of points considered as stabile benchmarks. Thanks to the new approach the point considered as reference were recognized as unstable. And for the others more consistent values of the displacements were obtained: several benchmarks demonstrated higher difference of displacement values in compare to the initial approach in adjustments ranging in the interval of –9 mm – +3 mm.
