재료물성치의 불확실성을 고려한 고정식 해상풍력터빈의 고유진동수에 대한 지반-말뚝 상호작용의 영향

Abstract

Monopiles have been most widely utilized for supporting offshore wind turbines (OWTs) in shallow waters. However, multi-member lattice-type structures including jackets and tripods are being also considered as one of the good alternatives to monopile foundations for relatively deep water in the range of 25-50 m of water depth owing to their technical and economic feasibility. Moreover, jacket structures are conventionally used in the oil and gas industry very popularly. However, there are still several issues need to be solved for utilization of multi-member lattice-type supporting structures for OWTs including pile-soil-interaction (PSI) effects, dynamically stable design, installation, and so on. In this study, the PSI effects on the dynamic properties of bottom-fixed OWTs are intensively investigated including monopile-, tripod- and jacket-supported OWTs. The tower and substructure are modeled using conventional beam elements with added mass and the pile foundations are modeled with beam and nonlinear spring elements, and the PSI effects on dynamic properties of the structure are evaluated using Monte Carlo simulation considering uncertainties in soil properties.o monopile foundations for relatively deep water in the range of 25-50 m of water depth owing to their technical and economic feasibility. Moreover, jacket structures are conventionally used in the oil and gas industry very popularly. However, there are still several issues need to be solved for utilization of multi-member lattice-type supporting structures for OWTs including pile-soil-interaction (PSI) effects, dynamically stable design, installation, and so on. In this study, the PSI effects on the dynamic properties of bottom-fixed OWTs are intensively investigated including monopile-, tripod- and jacket-supported OWTs. The tower and substructure are modeled using conventional beam elements with added mass and the pile foundations are modeled with beam and nonlinear spring elements, and the PSI effects on dynamic properties of the structure are evaluated using Monte Carlo simulation considering uncertainties in soil properties.