The construction of a wind turbine just at top of a dike is attractive from many points of view. However, a wind turbine is very large structure, a height up to 200 m is possible. Is it allowed to place such a structure on a dike? Or are additional requirements needed to have a safe situation?
A wind turbine itself is strongly loaded by the vibrations due to the dynamic wind load and the rotation of the blades. Also fatigue plays an important role in design. These vibrations will propagate into the soil. The influence of these vibrations in the soil should be evaluated. During its lifetime, the wind turbine will generate many cycles. The influence of this loading on the safety of the dike must be understood. In a storm case the wind turbine will be switched of. But, if a strong wind and high water coincide, the wind will shake the tower and its foundation. Does this influence the strength of the dike and thus the water safety?
This research focuses on the influence of vibrations from a wind turbine on the safety of a dike.
A wind turbine itself is strongly loaded by the vibrations due to the dynamic wind load and the rotation of the blades. Also fatigue plays an important role in design. These vibrations will propagate into the soil. The influence of these vibrations in the soil should be evaluated. During its lifetime, the wind turbine will generate many cycles. The influence of this loading on the safety of the dike must be understood. In a storm case the wind turbine will be switched of. But, if a strong wind and high water coincide, the wind will shake the tower and its foundation. Does this influence the strength of the dike and thus the water safety?
This research focuses on the influence of vibrations from a wind turbine on the safety of a dike.
Research plan
Each dike is evaluated with respect to all relevant failure mechanisms, see e.g. International levee handbook. Since a vibration level is not a parameter in this methods, this evaluation must be reconsidered for each failure mechanism. The basic principles must be recalled. The influence of vibrations on these basic principles must be evaluated. This leads to an influence of vibrations on each failure mechanism.
An additional aspect is the fact that the soil properties (stiffness, strength) might be influenced by the long-term vibrations from the wind-turbine, e.g. may the soil show some fatigue?
Additional to this aspect the existence of additional failure mechanisms cannot be excluded. This means that a general study of additional mechanisms must be done. Some possibilities will be evaluated.
The existence of a wind turbine foundation may have influence on other aspects, such as settlements of the soft subsoil, wave motion and scour in front of the dike and the interface between the structure and the soil. This study focus on the influence of vibrations, since these are typical for a wind turbine and generally seen as a knowledge gap. Interactions between vibrations and other well-known phenomena must be considered.
An additional aspect is the fact that the soil properties (stiffness, strength) might be influenced by the long-term vibrations from the wind-turbine, e.g. may the soil show some fatigue?
Additional to this aspect the existence of additional failure mechanisms cannot be excluded. This means that a general study of additional mechanisms must be done. Some possibilities will be evaluated.
The existence of a wind turbine foundation may have influence on other aspects, such as settlements of the soft subsoil, wave motion and scour in front of the dike and the interface between the structure and the soil. This study focus on the influence of vibrations, since these are typical for a wind turbine and generally seen as a knowledge gap. Interactions between vibrations and other well-known phenomena must be considered.
Utilisation plan
The theories will be applied to a case. All results are reported in reports and papers. These will be discussed with the user committee. At the end a guideline for the evaluation of the influence of vibrations from wind turbine is foreseen if the vibration aspects needs special attention and it seems possible to solve the vibration problems adequately.
