Determination of Strata Displacement Angles under Subcritical Mining

With the surface movement observation data derived from subcritical mining, Matlab curve fitting is applied to calculate predicting parameters of the probability integral method. Other conditions kept unchangeable, the size of the working face is extended to achieve full exploitation degree. The displacement and horizontal strain values are calculated by use of the probability integral method, and the subsidence, slope, curvature, horizontal strain curves are generated, thus, the displacement angles of strata under the condition of critical mining are consequently inversed. It is of theoretical significance and of practical value for delimiting the damaged scope and designing the protection pillar size reasonably.