SESSION VI: DEFORMATION MONITORING AND MODELLING OF LARGE DAMS 214 The 10th FIG International Symposium on Deformation Measurements USE OF GEODETIC MONITORING SURVEYS IN VERIFYING DESIGN PARAMETERS OF LARGE EARTHEN DAMS AT THE STAGE OF FILLING THE RESERVO

Deformation monitoring of large dams and their surroundings supplies information on the behaviour of the structure and its interaction with the bedrock. Monitoring results may also be used in verifying design parameters where the geotechnical parameters are of the highest importance. The determination of geotechnical parameters may be done in situ or in the laboratory. In laboratory testing, the selected samples may differ from one location to another, they may be disturbed during the collection, or the laboratory loading conditions may differ from natural conditions. Therefore, the comparison of the monitored data with the predicted data obtained during the design may give important information concerning the quality of the accepted geotechnical parameters. This paper discusses potentials and limitations of using geodetic monitoring surveys in verifying geotechnical parameters at the post-construction wetting stage during the filling of the reservoir. Large earthen dams of the Diamond Valley Lake (DVL) project in Southern California are used as an example of the discussion. A fully automated geodetic monitoring system has been established at the site of the project. A simulated analysis of loading effect during filling the reservoir (water loading and wetting), has been performed using the finite element method. The results of the FEM analysis of a partially saturated dam are comparable with the observed vertical displacements. 1