Hydrodynamic pressures on axisymmetric offshore structures considering seabed flexibility

Avilés, Javier; Li, Xiangyue

doi:10.1016/s0045-7949(01)00125-0

Cited by 29 publications

(11 citation statements)

References 8 publications

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“…e fluid damping effects on structural response include the viscous damping due to the fluid viscosity and the radiation damping due to the water compressible and free surface waves. Neglecting the fluid viscosity, many studies were performed to study the earthquake-induced hydrodynamic pressures on cylinders [3,11,15,17,21,24,26,29]. e study conducted by Liaw and Chopra [3] indicated that water compressibility and free surface waves can be neglected in solving the earthquakeinduced hydrodynamic pressure on circular cylinders.…”

Section: Pile-water Interactionmentioning

confidence: 99%

“…e earthquake-induced hydrodynamic forces on a single cylinder [11][12][13] and the seismic responses of cylinder surrounded by water [14][15][16] have been investigated widely in recent decades. e results indicated that effect of free surface waves on the earthquake-induced hydrodynamic force can be neglected and effect of water compressibility is quite important when the dimensionless frequency is greater than unity.…”

Section: Introductionmentioning

confidence: 99%

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Seismic Fragility Analysis of Bridge Group Pile Foundations considering Fluid-Pile-Soil Interaction

Zhang

Wang

2020

Shock and Vibration

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The cross-sea bridges play an important role to promote the development of regional economy. These bridges located in earthquake-prone areas may be subjected to severe earthquakes during their lifetime. Group pile foundations have been widely used in cross-sea bridges due to their structural efficiency, ease of construction, and low cost. This paper investigates the seismic performance of bridge pile foundation based on the seismic fragility analysis. Based on the analysis platform OpenSees, the three-dimensional finite model of the bridge pile foundation is developed, where the pile-water interaction is replaced by the added mass method, nonlinear p-y, t-z, and q-z elements are used to simulate pile-soil interaction, and the displacement of the surface ground motion due to seismic excitations is applied on all spring supports. The seismic fragility curves of the bridge pile foundation are generated by using the earthquake records recommended by FEMA P695 as input motions. The curvature ductility based fragility curves are obtained using seismic responses for different peak ground accelerations. The effects of pile-water interaction, soil conditions, and different types of ground motions on the bridge pier fragilities are studied and discussed. Seismic fragility of the pier-group pile system shows that Sec C (the bottom section of the pier) is the most vulnerable section in the example fluid-structure-soil interaction (FSSI) system for all four damage LSs. The seismic responses of Sec E (a pile section located at the interface of the soil layer and water layer) are much lower than other sections. The parameter analysis shows that pile-water interaction has slight influence (less than 5%) on the fragility curves of the bridge pier. For the bridge group pile foundations considering the fluid-pile-soil interaction, PNF may induce larger seismic response than far-field (FF) and no-pulse near field (NNF). The bridge pile foundation in stiff soil is most vulnerable to seismic damage than soft condition.

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Section: Pile-water Interactionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Seismic Fragility Analysis of Bridge Group Pile Foundations considering Fluid-Pile-Soil Interaction

Zhang

Wang

2020

Shock and Vibration

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“…Currently, the Morison equation [19][20][21][22][23][24][25][26][27] and radiation wave theory [28][29][30][31][32] are the 2 main methods used to calculate the hydrodynamic force. This paper chooses the Morison equation to derive the solution of the hydrodynamic force due to its simplicity and practicability.…”

Section: Hydrodynamic Force Solutionmentioning

confidence: 99%

Coordinative similitude law considering fluid‐structure interaction for underwater shaking table tests

Shi

et al. 2018

Earthq Engng Struct Dyn

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Summary Generally, when a model is made of the same material as the prototype in shaking table tests, the equivalent material density of the scaled model is greater than that of the prototype because mass is added to the model to satisfy similitude criteria. When the water environment is modeled in underwater shaking table tests, however, it is difficult to change the density of water. The differences in the density similitude ratios of specimen materials and water can affect the similitude ratios of the hydrodynamic and wave forces with those of other forces. To solve this problem, a coordinative similitude law is proposed for underwater shaking table tests by adjusting the width of the upstream face of the model or the wave height in the model test to match the similitude ratios of hydrodynamic and wave forces with those of other forces. The designs of the similitude relations were investigated for earthquake excitation, wave excitation, and combined earthquake and wave excitation conditions. Series of numerical simulations and underwater shaking table tests were performed to validate the proposed coordinative similitude law through a comparison of coordinative model and conventional model designed based on the coordinative similitude law and traditional artificial mass simulation, respectively. The results show that the relative error was less than 10% for the coordinative model, whereas it reached 80% for the conventional model. The coordinative similitude law can better reproduce the dynamic responses of the prototype, and thus, this similitude law can be used in underwater shaking table tests.

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“…The earthquake-induced hydrodynamic pressure on complex structures should be solved by numerical method, such as the finite element method (FEM) (Liao 1986, Liaw andChopra 1974), finite-difference scheme (Chen 1997), and the finite element technique incorporating the infinite element (Woo- Sun et al 1991). A special boundary method based on the use of a complete and non-singular set of Trefftz functions was presented for hydrodynamic pressure on axisymmetric offshore structures (Sun and Nogami 2010;Avilés and Li 2001). The free surface wave effect on the water-cylinder interaction is significant in wave force (Ti et al 2020), but it has been validated that free surface waves have less effect on the earthquake-induced hydrodynamic force on cylinders by Liaw and Chopra (1974) and Li and Yang (2013).…”

Section: Introductionmentioning

confidence: 99%

An accurate frequency-domain model of water interaction with cylinders of arbitrary shape during earthquakes

Zhao

Wang

et al. 2021

ABEN

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An accurate frequency domain model is proposed to analyze the seismic response of uniform vertical cylinders with arbitrary cross section surrounded by water. According to the boundary conditions and using the variables separation method, the vertical modes of the hydrodynamic pressure are firstly obtained. Secondly, the three-dimensional wave equation can be simplified to a two-dimensional Helmholtz equation. Introducing the scaled boundary coordinate, a scaled boundary finite element (SBFE) equation which is a linear non-homogeneous second-order ordinary equation is derived by weighted residual method. The dynamic-stiffness matrix equation for the problem is furtherly derived. The continued fraction is acted as the solution of the dynamic-stiffness matrix for cylinder dynamic interaction of cylinder with infinite water. The coefficient matrices of the continued fraction are derived recursively from the SBFE equation of dynamic-stiffness. The accuracy of the present method is verified by comparing the hydrodynamic force on circular, elliptical and rectangle cylinders with the analytical or numerical solutions. Finally, the proposed model is used to analyze the natural frequency and seismic response of cylinders.

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Hydrodynamic pressures on axisymmetric offshore structures considering seabed flexibility

Cited by 29 publications

References 8 publications

Seismic Fragility Analysis of Bridge Group Pile Foundations considering Fluid-Pile-Soil Interaction

Seismic Fragility Analysis of Bridge Group Pile Foundations considering Fluid-Pile-Soil Interaction

Coordinative similitude law considering fluid‐structure interaction for underwater shaking table tests

An accurate frequency-domain model of water interaction with cylinders of arbitrary shape during earthquakes

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