• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.524-530
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• 2020

The risk of offshore wind turbine support structures by scour has been proposed. The proposed utilize probabilities of scour depths and fragilities according to scour depth and a modification of a seismic risk analysis method. The probability distribution of scour depth was calculated using a equation which is suitable to consider marine environmental conditions such as significant wave height, significant period, and current velocity, and dynamic analysis was performed on an offshore wind turbine equipped with an suction bucket to find fragility. Then, the risk of offshore wind turbine support structure considering scour can be found by integrating the scour probability and the fragility.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.2
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• pp.79-89
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• 2016

If scour is occurred at shallow foundation of bridge, seismic performance of the bridge will be reduced. In order to evaluate accurate seismic response of bridge according to scour depths, modeling of foundation reflecting scour effect is important. In this study, taking into account the effect of the reduction in embedment depth of the shallow foundation by scouring, the soil around the foundation is modelled as an equivalent soil spring with various stiffness. Seismic fragility analyses for 3 types of bridges subjected to 4 types of ground motions classified into Site Class A, B, C, D are evaluated according to several scour depths. From the fragility analysis results, it can be observed that the deeper the scour depth, the higher probability of exceeding damage states. Also, seismic failure probability of asymmetric bridge is higher than that of symmetric bridge.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.374-382
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• 2021

The scour risk assessment was conducted for ultimate limit state of newly developed penta pod suction bucket support structures for a 5.5 MW offshore wind turbine. The hazard was found by using an empirical formula for scour depth suitable for considering marine environmental conditions such as significant wave height, significant wave period, and current velocity. The scour fragility curve was calculated by using allowable bearing capacity criteria of suction foundation. The scour risk was assessed by combining the scour hazard and the scour fragility.