Mining subsidence forecasting by structural and geomechanical analysis

Mining subsidence within Petrila coal field was surveyed since 1978 on several topographic profiles in accordance with the ongoing of the underground works. Availability of a good set of measured data on vertical and horizontal movements of the marks, correlated with detailed knowledge on lithologic and structural conditions provides for a complex modelling approach. Long time measurements are processed by a package of computer programs. Vertical movements, ground tilt and horizontal strain are computed for every year and marked on topographic profiles. Graphs of the running sums of the subsidence deformations and contour-maps are drown as main tools for quantitative prognosis. On this experimental basis, subsidence parameters are automatically forecasted for new developments of the underground coal mining during the next five and ten years. As overlays of the experimental data were tailored nummerical models to forecast the evolution of the mining subsidence. The prognosis is validated by analogy with the development of the actual observed subsidence parameters. Finaly, the forecasting package advances definit assessments on building stability risk level induced by the evolution of the ground surface subsidence.