Surface subsidence (vertical deformations) or mining-induced ground deformations (horizontal and vertical) are often an inevitable consequence of many mining methods. Itasca evaluates mining-induced subsidence related to the extraction of ore from both underground and open pit mines, together with dewatering-induced subsidence. Services provided include: field investigation for acquiring geomechanical and hydrogeological properties; subsidence back-analysis; and prediction of the magnitude and extent of subsidence related to a particular mine design in order to optimize location of infrastructure and understand any impacts on existing property and the surface environment.
Traditionally, empirical and analytical methods have been used to assess the limits of subsidence from underground mining. However, generally these methods are restricted to simplified, regular mining geometries and often limited to two-dimensional problem geometries.
Itasca engineers perform three-dimensional numerical modeling assessments of mining-induced subsidence. Through the calibration of observed and measured subsidence features at a number of operating and abandoned mine sites, Itasca has developed a rigorous methodology that predicts the limits of large-scale surface cracking, angular distortion, and horizontal ground strains capable of causing potential building damage of ground surface infrastructure.