Interconnection between monitoring and deterministic modeling of the behavior of large earth dams

Monitoring of deformations, whether using geodetic or geotechnical instrumentation, besides providing a warning system in case of an abnormal behaviour of the dam, may be used as a tool for a verification of design parameters. By comparing results of monitoring measurements with a deterministic (a-priori) model of deformation, one may determine and explain causes of deformation in a case of unexpected behaviour of the investigated object and its surrounding. Thus, the role of monitoring becomes much broader than just the conventional determination of the status of the deformable object. On the other hand, a predicted behaviour of the dam may be used in designing the monitoring scheme, giving information on the magnitude and location of the expected maximum deformation parameters. In addition, with properly designed monitoring surveys, one may also determine the actual deformation mechanism. The discussed problems are illustrated by three types of earth dams located in California, USA, and in Quebec, Canada.