Page - 1132 - in Book of Full Papers - Symposium Hydro Engineering

Fig. 3 Effect of ageing during design in consideration of the life span 7. MEASURES Maintenance works have to be conducted annually. The existing vegetation needs to be controlled and cut according to the design and operation requirements. Small damage has to be refurbished. All ways, roads and access options need to be kept functional in order to guarantee access also in critical situations such as MDE or extreme floods. As soon as the structure does not comply with the engineering standards and codes a need for action exists and the owner is obliged to corresponding measures within a given realization period. This period is not a fixed number but should correspond to the practical periods for the preparation of the detailed dam safety reports which is five to ten years. Various measures can be taken to upgrade the embankment dam in form of emergency action, partial rehabilitation works or a general upgrade. Rehabiliation works aim on the re-establishment of the former conditions. An upgrade shall improve the performance of the structure [15]. Embankment dams frequently suffer from an inadequate seepage situation, insuffucient slope stability or lack of dam height. Therefore, many measures are focussed on the installation of new sealings/barriers and the placement of drains and filters at the downstream toe in order also to stabilize the downstream slope. 1132