Bibliografías temáticas / Seabed Instability

Literatura académica sobre el tema "Seabed Instability"

Autor: Grafiati
Publicado: 4 de junio de 2021
Última modificación: 20 de febrero de 2023

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros

Elija tipo de fuente:

Índice

Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Seabed Instability".

Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.

También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.

Artículos de revistas sobre el tema "Seabed Instability"

1

Duran, Gerardo, Juan Manuel Mayoral, Edgar Mendoza y Rodolfo Silva. "SEABED INSTABILITY AROUND CAISSON BREAKWATERS". Coastal Engineering Proceedings 1, n.º 33 (11 de octubre de 2012): 13. http://dx.doi.org/10.9753/icce.v33.posters.13.

Texto completo
Resumen
A sensibility numerical study, considering the soil conditions found at Frontera Port in Tabasco, Mexico was conducted to identify the variables that govern the response of a seabed-foundation-structure system subject to wave loading. Among all the possible causes of instability, this study deals only with those associated with liquefaction failure of silty-sands due to cyclic shear stresses generated by regular waves. This research was prompted by the accidents that have occurred near Frontera Port, the most serious of which took place in October 2007 when the Usumacinta oil platform settled, causing 21 fatalities. Previous analysis of this accident (Leis, et al, 2007) suggested that the platform did not present any structural failure and that the accident was a result of an unexpected behavior of the seabed; probably liquefaction. In order to offer results regarding coastal protection activities in the study area, the analysis presented here was developed simulating a vertical breakwater similar to that constructed in 2001 at Barcelona instead of the oil platform. Puzrin, et al, 2009 report that in November 2001 four caissons of this breakwater failed due to seabed liquefaction. The adaptation of the design of the vertical breakwater to the study area conditions was estimated by means of the Goda, 1985 formula.
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Liu, Hong Jun, Hu Wang, Min Sheng Zhang y Xiu Hai Wang. "Experimental Study on Mechanism of Wave-Induced Silty Seabed Fluidization". Applied Mechanics and Materials 90-93 (septiembre de 2011): 2790–97. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.2790.

Texto completo
Resumen
Abstract. In this study, process of wave-induced silty seabed response was explored in a rectangle flume. Based on the experimental phenomena, the variations of pore water pressure and theory analysis, discussions were made on the mechanism of wave-induced silty seabed instability. Results indicated that seabed under wave nodes would experience fluidization and oscillation under wave actions, obvious pore pressure accumulation was observed at the same time. The mode of wave-induced silty seabed instability was fluidization. The mechanism of wave-induced silty seabed fluidization was a combination of excess pore water pressure and shear failure, the chief factor of fluidization could be ascribed to wave-induced cycling shear stress. The steady state strength was somewhat an expression of the level of wave-induced decrease of soil strenth that could finally reach, therefore, it could be used for the estimation of wave-induced fluidization of silty seabed.
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Jeng, Dong-Sheng y Liang Cheng. "Wave-induced seabed instability around a buried pipeline in a poro-elastic seabed". Ocean Engineering 27, n.º 2 (febrero de 2000): 127–46. http://dx.doi.org/10.1016/s0029-8018(98)00046-8.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Chari, T. R., C. R. Dawe y S. A. Barbour. "Model Studies of Wave-Seabed Interactions". Journal of Offshore Mechanics and Arctic Engineering 109, n.º 1 (1 de febrero de 1987): 67–74. http://dx.doi.org/10.1115/1.3256992.

Texto completo
Resumen
Several factors such as the wave characteristics, the seabed type, the sediment size, and the porosity characteristics influence the transient porewater pressure response below the mudline due to wave-seabed interaction. Experiments were conducted in a soil-wave tank in which the pressure variation profile inside a porous bed of sand was measured for different wave types. The measured pressures were correlated with simple theories based on wave energy dissipation in permeable seabed. Tests were conducted in which the combination of wave and soil conditions caused soil liquefaction and instability. These results were extrapolated to predict the potential conditions that may cause seabed instability in the Hibernia area of the Newfoundland Grand Banks. The experimental assembly, the results and correlations, and the limitations are discussed in this paper.
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Mizutani, Norimi y Ayman M. Mostafa. "Nonlinear Wave-Induced Seabed Instability Around Coastal Structures". Coastal Engineering Journal 40, n.º 2 (junio de 1998): 131–60. http://dx.doi.org/10.1142/s0578563498000091.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Hambly, Edmund C. "Punch‐Through Instability of Jack‐Up on Seabed". Journal of Geotechnical Engineering 111, n.º 4 (abril de 1985): 545–50. http://dx.doi.org/10.1061/(asce)0733-9410(1985)111:4(545).

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Zhang, Yongli, Yi Zhao y Zhenxia Yuan. "Effect of Seabed Instability on Pile Soil Pressure". Journal of Physics: Conference Series 1624 (octubre de 2020): 042071. http://dx.doi.org/10.1088/1742-6596/1624/4/042071.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Mostafa, Yasser E. y M. Hesham El Naggar. "Effect of seabed instability on fixed offshore platforms". Soil Dynamics and Earthquake Engineering 26, n.º 12 (diciembre de 2006): 1127–42. http://dx.doi.org/10.1016/j.soildyn.2005.12.010.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Rahman, M. S. "Wave‐induced instability of seabed: Mechanism and conditions". Marine Geotechnology 10, n.º 3-4 (julio de 1991): 277–99. http://dx.doi.org/10.1080/10641199109379896.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

HIROBE, Eiichi, Hajime ISHIDA y Chikayoshi YATOMI. "The instability region in anisotropic seabed to water waves". PROCEEDINGS OF HYDRAULIC ENGINEERING 41 (1997): 675–80. http://dx.doi.org/10.2208/prohe.41.675.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
Más fuentes

Tesis sobre el tema "Seabed Instability"

1

Li, Zhengxu. "Seabed Instability around a Submerged Breakwater due to Dynamic Loadings". Thesis, Griffith University, 2019. http://hdl.handle.net/10072/387387.

Texto completo
Resumen
A breakwater is one of common offshore structures for protecting ports and coastlines. Dynamic response of a seabed around a breakwater caused by the interactions between waves and currents is a critical aspect in evaluating the stability of the breakwater foundation. The existence of breakwater does not only affect the propagation pattern of nearby waves but also has a particular influence on the stability of the surrounding seabed. Under the interaction of waves and currents, liquefaction of the seabed foundation is one of main causes of breakwater damage, which must be fully considered in the design and construction of breakwaters. The periodic motion of waves exerts a cyclical pressure on the interface between seawater and seabed. Due to the effect of the cyclic wave pressures, the wave-induced residual pore pressure will increase, and the effective stress will decrease in the seabed, which could cause soil displacements and seabed deformation. Thus, under certain conditions, the shear failure and liquefaction of the seabed will occur. Furthermore, under the action of cyclic wave pressure, the normal stress and shear stress of the soil element in the seabed are cyclically changed which will cause the principal stress axis continuously to rotate. As a consequence, the plastic deformation of the soil is more significant, and the seabed is more prone to liquefaction. In this study, a one-way coupled two-dimensional numerical model is established integrating the fluid model and the seabed model. The soil liquefaction caused by the excess pore water pressure in the seabed is calculated by using the elasto-plastic porous medium soil model. The feasibility of the model was verified by comparison with the laboratory experiments, the centrifuge tests, and the previous numerical model data. It is shown that the numerical model can simulate the dynamic response of the seabed under wave-current interaction with high accuracy. By adopting the integrated numerical model, the dynamic seabed response generated by the rotation of the principal stress (PSR) axis is analysed under the cyclic wave loading. It is found that the PSR will affect the seabed dynamic response significantly. The liquefaction depth of the case considered PSR is much deeper than the results which did not consider the PSR effects, since the plastic strain of the soil caused by the PSR is involved in. Secondly, the dynamic response of seabed under different uniform current velocity and different wave conditions are solved. It is found that the following current accelerates the accumulation of pore water pressure, increases the displacement of the soil, and makes the seabed easier to liquefy, while the opposing current has an opposite effect. Also, the dynamic response of the seabed under wave loading is calculated, and detailed parameter analysis of the liquefaction potential of the seabed are carried out, including wave parameters (wave height, wave period), and seabed parameters (soil permeability, degree of saturation). In order to figure out the influence of the breakwater, a new-developed coupled model is established to simulate wave-seabed-breakwater interactions under cyclic wave loading. Firstly, the consolidation of the seabed under the effect of the self-weight of the breakwater is calculated. The dynamic response of the seabed around the breakwater and the seabed liquefaction depth are computed after consolidation process. Secondly, the interaction between wave and submerged breakwater is studied by the coupled numerical model. The influence of the height and crest width of the breakwater on the wave propagation is analysed. The variations of wave height in front of and behind the breakwater are compared. At the same time, the influence of breakwater height and crest width on liquefaction depth and liquefaction potential of seabed under wave action is analysed.
Thesis (Masters)
Master of Philosophy (MPhil)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Wang, Xiaoxiao. "Numerical Studies for Seabed Response around Marine Structures". Thesis, Griffith University, 2020. http://hdl.handle.net/10072/394681.

Texto completo
Resumen
Seabed instability induced by flow fluctuations is of particular significance for coastal engineers involved in design the soil foundation of offshore infrastructures, such as pipelines, breakwaters, and anchors and piles. Soil liquefaction generally occurs under cyclic loading when the excess pore water pressure overcomes the effective stress. The liquefied foundation will be incapable of supporting marine constructions and consequently structure damage and destruction will be induced because the soil will behave like heavy fluid and the shear resistance will vanish. The present study provides a new numerical model to simulate the soil behaviour for the water-structure-soil interactions. The conventional approaches for the wave-induced soil response, such as finite element method, finite volume method and finite difference method, have been reported in the literature. These techniques have been evolved and matured over the past decades and reliable results can be accessed. However, meshing is a time-consuming procedure during establishing a model. Moreover, mesh singularity is a challenging issue although it appears easily for the computational domain with a large deformation. In contrast to that, meshless methods attracted growing attentions from researchers because of its strong features, such as handling cases with a complex boundary or large deformation precisely. Furthermore, the continuity problem of interpolation can be improved. The adoption of meshless methods will reduce data storage and computational time. In the present study, a meshless approach is applied to establish fluid-seabed-structure models for marine pipelines or breakwaters. The present numerical modelling framework involves two sub-models associated with the fluid and soil field. The first is developed within OpenFOAM, in which the VARANS equations are solved. Finite difference two-step projection method and the forward time difference method are used for the space and temporal discretization, respectively. Biot’s equations are used to governing the behaviour of soil sediments, meanwhile local radial basis function collocation method and Crank-Nickson method are employed for space and temporal discretization, respectively. A one-way coupling algorithm is implemented on the interface between the flow water and solid domain.The dynamic wave pressure simulated in the hydrodynamic process will be exerted on the seabed and structure surface as a boundary condition based on the grid nodes of geotechnical model. The geotechnical model including marine structures in this study is a new meshfree model. Numerical simulations are implemented and validated with a series of analytical solutions and experimental results. After the accuracy and capability of the integrated model is confirmed, it is used to obtain the dynamic soil behaviour around marine structures, especially evaluating the potential failure risks for structures induced by liquefaction occurring in loosely deposited sand foundations. Computational outcomes illustrate that the newly proposed meshless geotechnical model is reliable to estimate wave-induced dynamic soil response, such as pore water pressure, effective stresses and shear stress, as well as the development of liquefaction depth from the seafloor or under the bottom of structures. It can be found that wave characteristics, soil properties and configuration of offshore pipeline or breakwater affect the distribution of liquefaction zone in the vicinity of marine structures considerably. The influence of wave randomness on the soil behaviour is presented, which demonstrates that random wave is a significant component during the design phase of offshore structure foundation.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Ulker, Mehmet Baris Can. "Dynamics of Saturated Porous Media: Wave Induced Response and Instability of Seabed". NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-08042009-161500/.

Texto completo
Resumen
Problems in fields ranging from geomechanics to biomechanics require response of saturated porous media subjected to dynamic loading. An engineering problem requiring the true behavior of saturated porous medium should consider the coupling of both fluid and solid phases yielding the simultaneous analysis of flow of pore fluid and deformation of solid skeleton. Depending on the nature of loading vis-à-vis the characteristics of the media, different formulations; fully-dynamic (FD), partially-dynamic (PD), quasi-static (QS) are possible. In this study, analytical solutions and numerical models are developed for the response of plane strain saturated porous media, and wave-induced response of seabed in free field and around a breakwater under pulsating/breaking waves. For each formulation, the results are presented with pore-pressure, shear and normal stress distributions within porous medium. The response is studied for various conditions and regions of applicability of formulations are identified in non-dimensional and actual parametric spaces. This can be used for a specific case with known loading and medium characteristics and may help engineers identify the necessary formulation to be used in a given problem. Effect of seabed-wave parameters and inertial terms on standing/breaking wave-induced pulsating/impact response of seabed-caisson system were investigated. The selection of the adequate formulation is decided depending upon the response variable and ranges of physical parameters. While FD formulation yields the minimum response in cyclic wave, for impacting wave it yields variable distributions in between the other two formulations. The areas of instantaneous liquefaction were identified inside the domain through contours of mean effective stress for both types of waves. Liquefied regions are concentrated at the front toe of rubble under cyclic wave which can initiate a vertical-horizontal movement and rotation towards the seabed causing structural failure. Liquefied areas in case of breaking waves are much larger compared to cyclic waves. Additional analyses made introducing a constitutive model for the inelastic behavior of soil to evaluate the nonlinear dynamic response of seabed reveal the importance of the inclusion of material nonlinearity effects.
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Han, Shuang. "Liquefaction around a Submarine Tunnel under Natural Dynamic Loading". Thesis, Griffith University, 2020. http://hdl.handle.net/10072/399434.

Texto completo
Resumen
Seabed instability surrounding an immersed tunnel is a vital engineering issue regarding the design and maintenance for submarine tunnel projects. It has been recognised that the pore water pressures and stresses in seabeds are affected by the water pressures generated by the natural dynamic loading. If the pore water pressure reaches the initial mean stress, the liquefaction could occur with the effective stress in seabed vanishing. To avoid seabed instability around the immersed tunnel, the study of seabed dynamic behaviour is necessary under the real hydrodynamic loading. Two mechanisms of wave-induced liquefaction has been reported in the literature, based on a mass of laboratory tests and field exploration, which are transient liquefaction and residual liquefaction. The transient liquefaction is motivated by the oscillatory excess pore water pressures under wave pressure vibration which usually happens with amplitude reduction and phase lag of pore pressure in seabed soil. While the residual liquefaction is on the consequence of the excess pore water pressure build-up under cyclic wave loading. The liquefied seabed soil will behave like a heavy fluid without any shear resistance to supported structures on it, thus leading to catastrophic failure of the immersed tunnel. In the present study, the main objective is to investigate the mechanism of soil response and liquefaction caused by waves and currents in the seabed foundation around the immersed tunnel. An integrated numerical model is established to analysis the seabed behaviour under natural dynamic loading, including ocean waves and currents. In the integrated model, the fluid sub-model is responsible for simulating the two-phase incompressible flow motion inside and outside the porous media, which is governed by the VARANS (Volume-Averages Reynolds Averaged Navier-Stokes) equation, while the seabed model is established adopting the LRBFCM with Biot’s "u− p" approximation which considered the inertial term of soil skeleton. The new conceptual meshfree model for residual mechanism considers the coupling effects between the development of the pore pressure build-up and the evolution of the seabed stresses by adding a source term associated with the shear stresses in the seabed. Good agreements with analytical solution and laboratory experiments validates this newly proposed numerical model. The LRBFCM is examined to be reliable in simulation of wave-induced oscillatory and residual liquefaction behaviour of a seabed. The wave-induced dynamic response of the oscillatory and residual seabed response is investigated adopting the developed integrated model. A series of results, including the seabed stresses, the pore pressure accumulation and the liquefaction potential in the seabed foundation are obtained. The existence of the immersed tunnel affects surrounding seabed dynamic behaviours significantly, including the seabed stresses and the pore water pressures, leading to the local redistribution in the adjacent region of the immersed tunnel. Both the maximum oscillatory and residual liquefied depth on the right-hand side of the tunnel is smaller than that on the left-hand side (the ocean wave is set as propagating along the x-direction from the left-hand side to the right-hand side). From the numerical results, the seabed oscillatory liquefaction is more likely to occur under a shallow water area with the waves of large wave height and long period, moreover, a seabed with lower permeability and degree of saturation is more likely to be liquefied. For the residual seabed response, the residual liquefaction is more likely to occur in the seabed foundations with low relative density and poor drainage condition. The seabed response around the immersed tunnel under combined nonlinear Stocks waves and currents loading is investigated both in oscillatory and residual mechanisms. The simulation results show that the risks of both oscillatory and residual liquefaction are much higher for the seabed under wave combined following currents, and the appearance of opposing current could decreased the probability of the liquefaction occurrence.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Liang, Zuodong. "Three-Dimensional Model for Seabed Instability around Offshore Pipelines under Combined Wave and Current Loadings". Thesis, Griffith University, 2020. http://hdl.handle.net/10072/391522.

Texto completo
Resumen
Seabed stability near offshore pipelines is one of the main concerns in engineering practice, being potentially affected by waves and ocean currents. The traditional model used to analyse soil behaviour near the pipeline assumes a two-dimensional interaction between the seabed and the marine structure. In other words, it is generally believed that the waves travel in the direction of the pipe. However, the actual marine environment is three-dimensional, with waves and currents approaching the structure from all directions. Based on a wide review of the literature, it may be claimed that the simplified 2D model no longer simulates the complex layouts of environment where offshore pipelines can be built, which should be represented as an integrated system. Therefore, the main objective of this project is to study the mechanism of soil response and liquefaction caused by waves and currents in the porous seabed near the offshore pipeline from a three-dimensional perspective. A three-dimensional numerical model is developed based on the Finite Volume Method (FVM) to analyse the instantaneous soil behaviour under the combined loads from both ocean waves and currents. In this integrated model, the hydrodynamic model is governed by the VARANS (Volume-Averaged Reynods Averaged Navier-Stokes) equation for simulating the two-phase incompressible flow motion outside and inside the porous media. The Biot’s consolidation equations are then solved for the soil responses by linking the dynamic wave pressure on the interface between the wave and seabed. The seabed behaviour is considered to be linear elastic with inversely small deformations. Overall good agreement with laboratory experimental measurements validates this newly proposed 3-D model. The numerical results reveal that the flow obliquity between the incident waves and the ocean currents has a non-negligible effect on the instantaneous pore-water pressure around the submarine pipeline, a phenomenon that cannot be observed in two dimensional numerical model. Further, a parametric study is conducted to show that the instantaneous pore-water pressure around the pipeline increases with decreasing flow obliquity; such influence can significantly increase with the increasing current velocity. Moreover, the liquefaction zone is more easily observed near the inlet of the ocean currents. By adopting the established FVM model, a numerical study on the soil response caused by waves and ocean currents near the trench structure has been conducted. The numerical results show that an offshore pipeline positioned in a trench layer is more stable than one directly laid on the seafloor. The following ocean currents can increase the liquefaction depth below the pipeline, while the opposing ocean currents can reduce the liquefaction depth near the pipeline. Moreover, the lee-wake vortex can be avoided with enough backfill thickness, which also decreases the occurrence of the onset of scour around the pipeline. Also, the nonlinear wave-current-induced seabed response around a pipe-protective cover system was investigated using the 3-D integrated model developed in OpenFOAM®. It was shown that, with sufficient quantity of stone covers and protective mattresses, the stability of the system can be maintained even with large current velocities. At this point, valuable suggestions can be drawn from the numerical results and then applied to engineering applications: (i) different backfill materials can be used to maintain the stability of a trenched pipeline with critical backfill thickness;(ii) pipelines laid directly on the surface of the seabed can be protected by a full stone cover or protective mattress under the environmental loadings from both ocean waves and currents with different directions; (iii) the protective mattress can be economically constructed over the pipeline with critical spacing to avoid an increase in the engineering budget.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Shabani, Behnam. "Wave-Associated Seabed Behaviour near Submarine Buried Pipelines". Thesis, The University of Sydney, 2008. http://hdl.handle.net/2123/3532.

Texto completo
Resumen
Soil surrounding a submarine buried pipeline consolidates as ocean waves propagate over the seabed surface. Conventional models for the analysis of soil behaviour near the pipeline assume a two-dimensional interaction problem between waves, the seabed soil, and the structure. In other words, it is often considered that water waves travel normal to the orientation of pipeline. However, the real ocean environment is three-dimensional and waves approach the structure from various directions. It is therefore the key objective of the present research to study the seabed behaviour in the vicinity of marine pipelines from a three-dimensional point of view. A three-dimensional numerical model is developed based on the Finite Element Method to analyse the so-called momentary behaviour of soil under the wave loading. In this model, the pipeline is assumed to be rigid and anchored within a rigid impervious trench. A non-slip condition is considered to exist between the pipe and the surrounding soil. Quasi-static soil consolidation equations are then solved with the aid of the proposed FE model. In this analysis, the seabed behaviour is assumed to be linear elastic with the soil strains remaining small. The influence of wave obliquity on seabed responses, i.e. the pore pressure and soil stresses, are then studied. It is revealed that three-dimensional characteristics systematically affect the distribution of soil response around the circumference of the underwater pipeline. Numerical results suggest that the effect of wave obliquity on soil responses can be explained through the following two mechanisms: (i) geometry-based three-dimensional influences, and (ii) the formation of inversion nodes. Further, a parametric study is carried out to investigate the influence of soil, wave and pipeline properties on wave-associated pore pressure as well as principal effective and shear stresses within the porous bed, with the aid of proposed three-dimensional model. There is strong evidence in the literature that the failure of marine pipelines often stems from the instability of seabed soil close to this structure, rather than from construction deficiencies. The wave-induced seabed instability is either associated with the soil shear failure or the seabed liquefaction. Therefore, the developed three-dimensional FE model is used in this thesis to further investigate the instability of seabed soil in the presence of a pipeline. The widely-accepted criterion, which links the soil liquefaction to the wave-induced excess pressure is used herein to justify the seabed liquefaction. It should be pointed out that although the present analysis is only concerned with the momentary liquefaction of seabed soil, this study forms the basis for the three-dimensional analysis of liquefaction due to the residual mechanisms. The latter can be an important subject for future investigations. At the same time, a new concept is developed in this thesis to apply the dynamic component of soil stress angle to address the phenomenon of wave-associated soil shear failure. At this point, the influence of three-dimensionality on the potentials for seabed liquefaction and shear failure around the pipeline is investigated. Numerical simulations reveal that the wave obliquity may not notably affect the risk of liquefaction near the underwater pipeline. But, it significantly influences the potential for soil shear failure. Finally, the thesis proceeds to a parametric study on effects of wave, soil and pipeline characteristics on excess pore pressure and stress angle in the vicinity of the structure.
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Shabani, Behnam. "Wave-Associated Seabed Behaviour near Submarine Buried Pipelines". University of Sydney, 2008. http://hdl.handle.net/2123/3532.

Texto completo
Resumen
Master of Engineering (Research)
Soil surrounding a submarine buried pipeline consolidates as ocean waves propagate over the seabed surface. Conventional models for the analysis of soil behaviour near the pipeline assume a two-dimensional interaction problem between waves, the seabed soil, and the structure. In other words, it is often considered that water waves travel normal to the orientation of pipeline. However, the real ocean environment is three-dimensional and waves approach the structure from various directions. It is therefore the key objective of the present research to study the seabed behaviour in the vicinity of marine pipelines from a three-dimensional point of view. A three-dimensional numerical model is developed based on the Finite Element Method to analyse the so-called momentary behaviour of soil under the wave loading. In this model, the pipeline is assumed to be rigid and anchored within a rigid impervious trench. A non-slip condition is considered to exist between the pipe and the surrounding soil. Quasi-static soil consolidation equations are then solved with the aid of the proposed FE model. In this analysis, the seabed behaviour is assumed to be linear elastic with the soil strains remaining small. The influence of wave obliquity on seabed responses, i.e. the pore pressure and soil stresses, are then studied. It is revealed that three-dimensional characteristics systematically affect the distribution of soil response around the circumference of the underwater pipeline. Numerical results suggest that the effect of wave obliquity on soil responses can be explained through the following two mechanisms: (i) geometry-based three-dimensional influences, and (ii) the formation of inversion nodes. Further, a parametric study is carried out to investigate the influence of soil, wave and pipeline properties on wave-associated pore pressure as well as principal effective and shear stresses within the porous bed, with the aid of proposed three-dimensional model. There is strong evidence in the literature that the failure of marine pipelines often stems from the instability of seabed soil close to this structure, rather than from construction deficiencies. The wave-induced seabed instability is either associated with the soil shear failure or the seabed liquefaction. Therefore, the developed three-dimensional FE model is used in this thesis to further investigate the instability of seabed soil in the presence of a pipeline. The widely-accepted criterion, which links the soil liquefaction to the wave-induced excess pressure is used herein to justify the seabed liquefaction. It should be pointed out that although the present analysis is only concerned with the momentary liquefaction of seabed soil, this study forms the basis for the three-dimensional analysis of liquefaction due to the residual mechanisms. The latter can be an important subject for future investigations. At the same time, a new concept is developed in this thesis to apply the dynamic component of soil stress angle to address the phenomenon of wave-associated soil shear failure. At this point, the influence of three-dimensionality on the potentials for seabed liquefaction and shear failure around the pipeline is investigated. Numerical simulations reveal that the wave obliquity may not notably affect the risk of liquefaction near the underwater pipeline. But, it significantly influences the potential for soil shear failure. Finally, the thesis proceeds to a parametric study on effects of wave, soil and pipeline characteristics on excess pore pressure and stress angle in the vicinity of the structure.
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

"Sand Foundation Instability due to Wave-Seabed-Structure Dynamic Interaction". Thesis, 2008. http://hdl.handle.net/2237/10077.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Nakamura, Tomoaki y 友昭 中村. "Sand Foundation Instability due to Wave-Seabed-Structure Dynamic Interaction". Thesis, 2008. http://hdl.handle.net/2237/10077.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

Ülker, Mehmet Barış Can. "Dynamics of saturated porous media wave induced response and instability of seabed /". 2009. http://www.lib.ncsu.edu/theses/available/etd-08042009-161500/unrestricted/etd.pdf.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.

Capítulos de libros sobre el tema "Seabed Instability"

1

Jeng, Dong-Sheng. "Wave-Induced Seabed Instability". En Porous Models for Wave-seabed Interactions, 79–108. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-33593-8_4.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Yincan, Ye. "Analyses of Instability of Seabed and Substrate in the East China Sea". En Oceanology, 333–38. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4205-9_37.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Kassner, K. "Morphological Instability: Dendrites, Seaweed, and Fractals". En Science and Technology of Crystal Growth, 193–208. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0137-0_15.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Nadim, Farrokh, Tore J. Kvalstad y Tom Guttormsen. "Quantification of risks associated with seabed instability at Ormen Lange". En Ormen Lange–an Integrated Study for Safe Field Development in the Storegga Submarine Area, 311–18. Elsevier, 2005. http://dx.doi.org/10.1016/b978-0-08-044694-3.50030-5.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Oboni, F. y Z. Hlobil. "18. Building a residential complex on a slow deep-seated slope instability". En Slope stability engineering developments and applications, 113–17. Thomas Telford Publishing, 1991. http://dx.doi.org/10.1680/ssedaa.16606.0019.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.

Actas de conferencias sobre el tema "Seabed Instability"

1

Jeng, Dong-Sheng. "Wave-Induced Seabed Instability around a Breakwater". En Coastal Structures and Solutions to Coastal Disasters Joint Conference 2015. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480304.083.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Rafiei, Amin, M. S. Rahman y M. A. Gabr. "Coupled Analysis of Wave, Structure, and Sloping Seabed Interaction: Response and Instability of Seabed". En Eighth International Conference on Case Histories in Geotechnical Engineering. Reston, VA: American Society of Civil Engineers, 2019. http://dx.doi.org/10.1061/9780784482124.019.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Day, Kevin. "Seabed canyons: slope instability problems, or just interesting features?" En Offshore Technology Conference. Offshore Technology Conference, 2002. http://dx.doi.org/10.4043/14101-ms.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Zhang, Yong-li y Jie Li. "Seabed instability simplified model and application in offshore wind turbine". En 2009 2nd International Conference on Power Electronics and Intelligent Transportation System (PEITS). IEEE, 2009. http://dx.doi.org/10.1109/peits.2009.5406794.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Gao, Fuping, Jing Cao, Xiting Han, Yong Sha, En-yong Zhang, Yingxiang Wu y Jinsheng Cui. "Full-Scale Physical Modeling of Pipeline Instability on a Sloping Seabed". En Offshore Technology Conference. Offshore Technology Conference, 2011. http://dx.doi.org/10.4043/21260-ms.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Rafiei, Amin, M. A. Gabr, M. S. Rahman y Majid Ghayoomi. "Cyclic Response and Instability Analysis of Seabed With Cohesionless Soils Due to Surging Waves". En ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/omae2021-62635.

Texto completo
Resumen
Abstract Surface waves may generate significant loadings on the seabed destabilizing sediments and the supporting marine structures. This threat is more pronounced in shallower water depths where the cyclic wave loading may induce residual pore water pressure in sediments triggering soil liquefaction. In this paper, a coupled numerical framework is presented to evaluate the interaction of waves and horizontal seabed considering nonlinear cyclic behavior of the cohesionless soil. A simple experimental model is employed for concurrent simulation of nonlinear buildup of pore pressure and deformation of saturated sand subjected to the cyclic loadings. The model (in elemental scale) is incorporated into a finite element code to solve the interaction of wave and seabed. Poro-elastoplastic response of the seabed is obtained by modifying the Biot’s coupled flow-and-deformation equations by adding equivalent nodal force terms associated with residual deformations of the soil. Potential flow theory is adopted for the fluid domain to model wave-induced pressure and flow fields. The governing equations and boundary conditions are solved using finite element analysis in time domain. The numerical framework is verified against results of cyclic triaxial compression tests and analytical solutions. Parametric studies are conducted to evaluate the effects of wave characteristics on triggering the residual liquefaction. The numerical results indicate good agreements with experimental measures. The results also show that for large waves, the progressive buildup of pore pressure in sediments may become high enough, leading to residual liquefaction. The details of the numerical model and the potential of residual liquefaction within the seabed soil are discussed.
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Ulker, M. B. C., M. S. Rahman y M. N. Guddati. "Standing Wave-Induced Dynamic Response and Instability of Seabed Under a Caisson Breakwater". En ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20524.

Texto completo
Resumen
The wave-induced dynamic response and instability of the porous seabed and the rubble mound foundation under a composite caisson-type breakwater is studied using finite elements. In this study the focus is on the effect of inertial terms on the dynamic response and instability of the foundation material underneath the breakwater. It is assumed that a fully standing wave condition occurs in front of the caisson under the cyclic wave action and the dynamic response of the seabed and rubble mound is presented in terms of pore pressures and stresses induced around the breakwater. A complete formulation of the fully dynamic (FD) response requires inclusion of the inertial terms associated with both the motion of solid skeleton and that of pore fluid. However, partly dynamic (PD) and quasi-static (QS) idealizations are also possible. The objective of this study is to investigate the standing wave induced dynamic response and instability of seabed-rubble-breakwater system.
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Ülker, M. B. Can. "Preface of the "Symposium on analysis of wave-induced response and instability of seabed"". En NUMERICAL ANALYSIS AND APPLIED MATHEMATICS ICNAAM 2012: International Conference of Numerical Analysis and Applied Mathematics. AIP, 2012. http://dx.doi.org/10.1063/1.4756440.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Xu, Guohui, Xin Wang, Congcong Wei, Zibu Fu y Qingpeng Zhao. "Calculation of Wave-Induced Shallow Stratum Seabed Slides in the Subaqueous Yellow River Delta". En ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79069.

Texto completo
Resumen
Wave-induced seabed slide could happen even at very gently sloping silty seabed. Based on the wave-seabed interaction, the safety coefficient calculation model of wave-induced gentle seabed slides in the seabed instability was carried out using limit equilibrium method, Bishop Method, in this paper. The calculated results shows that the effective internal cohesion c′ and the effective internal friction angle φ′ affect the location of slip surface and the magnitude of the safety coefficient significantly. The safety coefficient rises linearly with the increases of c′ and φ′ at a fixed depth. The results fit reasonable well with the slide calculation results from a wave flume experiment in laboratory. Additionally, it was concluded that the silty seabed tended to slide under wave actions at the depth less than 5 meters in the Yellow River Subaqueous Delta.
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

Devries, Kellen y Matthew Hall. "Comparison of Seabed Friction Formulations in a Lumped-Mass Mooring Model". En ASME 2018 1st International Offshore Wind Technical Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/iowtc2018-1099.

Texto completo
Resumen
This paper explores the impact of friction models on mooring line simulations. Seabed friction can play an important role in the determination of mooring loads of slack-moored floating offshore wind turbines. Most mooring models include a relatively simple seabed friction formulation, if any, and little examination of their accuracy is available in literature. Current implementations typically represent seabed contact as coulombic friction with ramping near zero velocity to mitigate instability in the numerical time integration. To assess the impact of this friction model’s use, we compare it against a more sophisticated friction model. This model differentiates between static and kinetic friction, where the former is dependent upon the forces acting on the line and the latter is a function of seabed’s normal response. Both friction models have been implemented into the MoorDyn mooring dynamics simulator and tested under a set of prescribed scenarios including snap loads and oscillatory motion, where the fairlead of a mooring line was driven along both linear and circular paths. Additionally, coupled floating wind turbine simulations using the OC4-DeepCwind semisubmersible show how the friction models affect the platform global response and the extreme and fatigue mooring loads. The results highlight practical differences between the models in terms of both loads prediction and simulation stability/consistency.
Los estilos APA, Harvard, Vancouver, ISO, etc.

Informes sobre el tema "Seabed Instability"

1

Christian, H. A., D. C. Mosher, J. V. Barrie, J. A. Hunter y J L Luternauer. Seabed slope instability on the Fraser River delta. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1998. http://dx.doi.org/10.4095/210045.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Piper, D. J. W., R. Sparkes, D. C. Mosher, A. N. Shor y J A Farre. Seabed Instability near the Epicentre of the 1929 Grand Banks Earthquake. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1985. http://dx.doi.org/10.4095/129959.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Christian, H. A., T. Mulder y R. C. Courtney. Seabed slope instability on the Fraser River Delta, Vancouver, British Columbia, Canada. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1995. http://dx.doi.org/10.4095/205044.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
También puede estar interesado en las bibliografías ampliadas sobre el tema "Seabed Instability" para tipos de fuentes particulares:
Artículos de revistas
Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!

Pasar a la bibliografía