A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Probabilistic seismic responses and failure analyses of free-spanning subsea pipelines under offshore spatial earthquake motions
https://orcid.org/0000-0003-0761-370X
Abstract A comprehensive literature review in seismic analysis of free-spanning offshore pipelines (FSOPs) reveals that two critical aspects, i.e. the offshore earthquake motions and various uncertainty sources, have been normally ignored in numerous previous studies. Specifically, the offshore pipelines are usually modeled by assuming all the structural parameters to be fixed and are excited using the onshore earthquake motions. Such analytical schemes may result in severe misestimates of seismic response predictions of FSOPs. In this paper, a probabilistic approach is developed for numerically investigating the seismic responses and failure mechanisms of FSOPs subjected to the offshore spatial earthquake motions (Off-SEMs). For this purpose, a buried offshore pipeline of API X65 with a free span of 30 m is selected and the corresponding three-dimensional finite element (3D FE) model is established in the ABAQUS software, where the soil–pipe and water–pipe interactions are modeled using the nonlinear soil springs and added mass and damping methods, respectively. Then, the three-dimensional Off-SEMs are stochastically synthesized by explicitly considering the effects of spatial variability and overlying seawater. Next, the general law of dynamic responses and failure modes of FSOPs subjected to the Off-SEMs is analyzed and summarized by the deterministic dynamic analysis. Defining the earthquake motions, structural modeling and soil properties as uncertain sources, the relative sensitivity of seismic behaviors to uncertain parameters involved in these uncertain sources is identified separately by the sensitivity analysis. Finally, uncertainty analysis is performed to examine and discuss the influence of different types of uncertainty sources on the seismic behaviors of FSOPs. Numerical results indicate that the pipeline diameter has the highest influence on the seismic behaviors of FSOPs, while the Poisson’s ratio of pipeline material has the smallest effect; uncertainties in earthquake motions, structural modeling and soil properties have significant contributions to the dynamic characteristics and seismic behaviors.
Highlights Seismic failure mechanism of a FSOP is analyzed and summarized. Off-SEMs are used as inputs to assess the seismic responses and failure probabilities of the FSOP. Uncertainties in earthquakes, structural modeling and soil properties have great impacts on seismic behaviors of FSOPs. The geometric property uncertainties have a larger impact on the seismic performance of FSOPs than the material property uncertainties. The pipeline diameter is the most significant parameter for the seismic behaviors of FSOPs.
Probabilistic seismic responses and failure analyses of free-spanning subsea pipelines under offshore spatial earthquake motions
https://orcid.org/0000-0003-0761-370X
Abstract A comprehensive literature review in seismic analysis of free-spanning offshore pipelines (FSOPs) reveals that two critical aspects, i.e. the offshore earthquake motions and various uncertainty sources, have been normally ignored in numerous previous studies. Specifically, the offshore pipelines are usually modeled by assuming all the structural parameters to be fixed and are excited using the onshore earthquake motions. Such analytical schemes may result in severe misestimates of seismic response predictions of FSOPs. In this paper, a probabilistic approach is developed for numerically investigating the seismic responses and failure mechanisms of FSOPs subjected to the offshore spatial earthquake motions (Off-SEMs). For this purpose, a buried offshore pipeline of API X65 with a free span of 30 m is selected and the corresponding three-dimensional finite element (3D FE) model is established in the ABAQUS software, where the soil–pipe and water–pipe interactions are modeled using the nonlinear soil springs and added mass and damping methods, respectively. Then, the three-dimensional Off-SEMs are stochastically synthesized by explicitly considering the effects of spatial variability and overlying seawater. Next, the general law of dynamic responses and failure modes of FSOPs subjected to the Off-SEMs is analyzed and summarized by the deterministic dynamic analysis. Defining the earthquake motions, structural modeling and soil properties as uncertain sources, the relative sensitivity of seismic behaviors to uncertain parameters involved in these uncertain sources is identified separately by the sensitivity analysis. Finally, uncertainty analysis is performed to examine and discuss the influence of different types of uncertainty sources on the seismic behaviors of FSOPs. Numerical results indicate that the pipeline diameter has the highest influence on the seismic behaviors of FSOPs, while the Poisson’s ratio of pipeline material has the smallest effect; uncertainties in earthquake motions, structural modeling and soil properties have significant contributions to the dynamic characteristics and seismic behaviors.
Highlights Seismic failure mechanism of a FSOP is analyzed and summarized. Off-SEMs are used as inputs to assess the seismic responses and failure probabilities of the FSOP. Uncertainties in earthquakes, structural modeling and soil properties have great impacts on seismic behaviors of FSOPs. The geometric property uncertainties have a larger impact on the seismic performance of FSOPs than the material property uncertainties. The pipeline diameter is the most significant parameter for the seismic behaviors of FSOPs.
Probabilistic seismic responses and failure analyses of free-spanning subsea pipelines under offshore spatial earthquake motions
https://orcid.org/0000-0003-0761-370X
Abstract A comprehensive literature review in seismic analysis of free-spanning offshore pipelines (FSOPs) reveals that two critical aspects, i.e. the offshore earthquake motions and various uncertainty sources, have been normally ignored in numerous previous studies. Specifically, the offshore pipelines are usually modeled by assuming all the structural parameters to be fixed and are excited using the onshore earthquake motions. Such analytical schemes may result in severe misestimates of seismic response predictions of FSOPs. In this paper, a probabilistic approach is developed for numerically investigating the seismic responses and failure mechanisms of FSOPs subjected to the offshore spatial earthquake motions (Off-SEMs). For this purpose, a buried offshore pipeline of API X65 with a free span of 30 m is selected and the corresponding three-dimensional finite element (3D FE) model is established in the ABAQUS software, where the soil–pipe and water–pipe interactions are modeled using the nonlinear soil springs and added mass and damping methods, respectively. Then, the three-dimensional Off-SEMs are stochastically synthesized by explicitly considering the effects of spatial variability and overlying seawater. Next, the general law of dynamic responses and failure modes of FSOPs subjected to the Off-SEMs is analyzed and summarized by the deterministic dynamic analysis. Defining the earthquake motions, structural modeling and soil properties as uncertain sources, the relative sensitivity of seismic behaviors to uncertain parameters involved in these uncertain sources is identified separately by the sensitivity analysis. Finally, uncertainty analysis is performed to examine and discuss the influence of different types of uncertainty sources on the seismic behaviors of FSOPs. Numerical results indicate that the pipeline diameter has the highest influence on the seismic behaviors of FSOPs, while the Poisson’s ratio of pipeline material has the smallest effect; uncertainties in earthquake motions, structural modeling and soil properties have significant contributions to the dynamic characteristics and seismic behaviors.
Highlights Seismic failure mechanism of a FSOP is analyzed and summarized. Off-SEMs are used as inputs to assess the seismic responses and failure probabilities of the FSOP. Uncertainties in earthquakes, structural modeling and soil properties have great impacts on seismic behaviors of FSOPs. The geometric property uncertainties have a larger impact on the seismic performance of FSOPs than the material property uncertainties. The pipeline diameter is the most significant parameter for the seismic behaviors of FSOPs.
Probabilistic seismic responses and failure analyses of free-spanning subsea pipelines under offshore spatial earthquake motions
Pan, Haiyang (author) / Li, Hong-Nan (author) / Li, Chao (author) / Tian, Li (author)
Thin-Walled Structures ; 179
2022-06-02
Article (Journal)
Electronic Resource
English
Free vibrations of free spanning offshore pipelines
| Elsevier | 2013
Free vibrations of free spanning offshore pipelines
| Online Contents | 2013
Prediction of natural frequency of free spanning subsea pipelines
| Springer Verlag | 2010