Use of deformation monitoring results in solving geomechanical problems—case studies

Abstract

Deformation analysis of any type of a deformable body includes geometrical analysis and physical interpretation. The ultimate goal of the geometrical analysis is to determine in the whole deformable object the displacement and strain fields in the space and time domains. Physical interpretation is to establish the relationship between the causative factors (loads) and the deformations. The latter may be obtained by deterministic modelling of deformations using, for example, finite element method (FEM). By comparing the geometrical and deterministic model of deformations, one can verify the designed behaviour of the deformable object. In addition, with properly designed monitoring surveys, one may also determine the actual deformation mechanism and explain causes of deformation in a case of unexpected behaviour of the investigated object. Thus, the role of deformation monitoring surveys becomes much broader than just the conventional determination of the geometrical status of the deformable object. In this presentation two examples are given on the use of geodetic monitoring surveys in the (a) determination of effects of hydrological changes on ground subsidence in a potash mine in Canada and (b) verification of geomechanical parameters of a large earth dam in California during the filling up of the water reservoir.