Underground mining extraction causes the displacement and changes of stress fields in the surrounding rock mass. The determination of the changes is extremely important when the mining activity takes place in the proximity of post-flotation tailing ponds, which may affect the stability of the tailing dams. The deterministic modeling based on principles of continuum mechanics with the use of numerical methods, e.g. finite element method (FEM) should be used in all problems of predicting rock mass displacements and changes of stress field, particularly in cases of complex geology and complex mining methods. The accuracy of FEM solutions depends mainly on the quality of geomechanical parameters of the geological strata. The parameters, e.g. young modulus of elasticity, may require verification through a comparison with measured surface deformations using geodetic methods. This paper presents application of FEM in predicting effects of underground mining on the surface displacements in the area of the KGHM safety pillar of the tailing pond of the OUOW Żelazny Most. The area has been affected by room and pillar mining with roof bending in the years 2008-2016 and will be further exposed to room-and-pillar extraction with hydraulic filling in the years 2017–2019.

Hydrocarbon production under certain geological conditions of these deposits can cause surface subsidence and deformation of the terrain surface. Such deformations appear as subsidence troughs of considerable range and the magnitude of the subsidence depending on the total thickness of the reservoir, compaction properties of reservoir and on the number of other factors. In the past there have been widely recognized magnitudes of the subsidence up to 9 meters. The stress zones in the subsidence trough may affect the buildings and surface structures. However there have been well known some cases of destroyed boreholes or pipelines belonging to the gas or oil mine. Therefore there is a requirement to analyze the possibility of occurrence unfavorable phenomenon on the ground surface, to monitor surface deformations during production and to protect surface infrastructure located in the range of mining influences. In the paper the issue of surface subsidence caused by hydrocarbon production has been presented. The cause - effect relationship between the compaction of thereservoir rock and the subsidence of surface area has been assumed. The prediction model base on the influence function and on the superposition of elementary influences. For the purpose of building damage protection a new model of risk assessment has been developed. This model base on the elements of fuzzy logicallows to incorporate in the analysis the quantitative and qualitative factors that contribute to the risk of building damage. Use of the fuzzy logic made it possible to obtain one value which clearly discriminate the risk of buildings damage. However, risk analyzes of damage to the large number of buildings has been required additional tools. The spatial analysis has been made by using GIS. The subjects of the paper have been illustrated with a practical example.