Usually, the action of sea ice on offshore engineering structures is one of the controlling loads in cold waters engineering structure design. The reasonable selection of environmental condition and the physical mecha...Usually, the action of sea ice on offshore engineering structures is one of the controlling loads in cold waters engineering structure design. The reasonable selection of environmental condition and the physical mechanical properties of ice in the region are directly related to the structure design, operation and safety. In this paper, the sea ice force acting on the structure, the physical mechanical properties of ice and the selection of parameters in calculation are discussed. Some suggestions are proposed as to the calculation of various kinds of ice loads acting on the structure.展开更多
Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass a...Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.展开更多
根据国内外调研资料,归纳整理海上LNG(液化天然气)接收站重力式基础结构(GBS,gravity based structure)的概况、结构设计方法及难点解决方案,并提出海上重力式基础结构LNG接收站在国内的应用展望和亟待解决的问题。亚得里亚海LNG接收站...根据国内外调研资料,归纳整理海上LNG(液化天然气)接收站重力式基础结构(GBS,gravity based structure)的概况、结构设计方法及难点解决方案,并提出海上重力式基础结构LNG接收站在国内的应用展望和亟待解决的问题。亚得里亚海LNG接收站的结构设计为GBS的典型结构,基于半概率极限状态设计法,采用有限元方法分析获得从建造到应用的各阶段结构受力状态。结构设计的主要难点包括LNG储罐要求的混凝土温度梯度控制、绝缘材料湿度梯度控制,以及结构整体的抗震可靠性。通过预埋发热电缆和安装柔性钢衬垫隔绝水汽,可以解决温度和梯度的变化,通过有限元分析地震作用下的地基-结构相互作用,以论证结构抗震试验。由于资料有限,需要对GBS的详细设计及施工等开展进一步研究,其在我国未来的能源进口、海上天然气开采等方面具备应用潜力。展开更多
文摘Usually, the action of sea ice on offshore engineering structures is one of the controlling loads in cold waters engineering structure design. The reasonable selection of environmental condition and the physical mechanical properties of ice in the region are directly related to the structure design, operation and safety. In this paper, the sea ice force acting on the structure, the physical mechanical properties of ice and the selection of parameters in calculation are discussed. Some suggestions are proposed as to the calculation of various kinds of ice loads acting on the structure.
文摘Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.
文摘根据国内外调研资料,归纳整理海上LNG(液化天然气)接收站重力式基础结构(GBS,gravity based structure)的概况、结构设计方法及难点解决方案,并提出海上重力式基础结构LNG接收站在国内的应用展望和亟待解决的问题。亚得里亚海LNG接收站的结构设计为GBS的典型结构,基于半概率极限状态设计法,采用有限元方法分析获得从建造到应用的各阶段结构受力状态。结构设计的主要难点包括LNG储罐要求的混凝土温度梯度控制、绝缘材料湿度梯度控制,以及结构整体的抗震可靠性。通过预埋发热电缆和安装柔性钢衬垫隔绝水汽,可以解决温度和梯度的变化,通过有限元分析地震作用下的地基-结构相互作用,以论证结构抗震试验。由于资料有限,需要对GBS的详细设计及施工等开展进一步研究,其在我国未来的能源进口、海上天然气开采等方面具备应用潜力。
