Letteratura scientifica selezionata sul tema "Suction caisson"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Suction caisson".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Articoli di riviste sul tema "Suction caisson"
1
Iskander, Magued, Sherif El-Gharbawy e Roy Olson. "Performance of suction caissons in sand and clay". Canadian Geotechnical Journal 39, n. 3 (1 giugno 2002): 576–84. http://dx.doi.org/10.1139/t02-030.
Testo completoAbstract (sommario):
The use of suction caissons (suction piles) in marine environments has been increasing in the last decade. A suction caisson is a steel pipe with an open bottom and a closed top that is inserted into the ground by pumping water out of it. Pumping creates a differential pressure across the caisson's top that pushes it into place, thus eliminating the need for pile driving. There are a number of uncertainties in the design of suction caissons. First, the state of stress and soil conditions adjacent to a suction caisson differs from those around typical driven piles or drilled shafts. Second, the axial load capacity of suction caissons depends on the rate of loading, hydraulic conductivity, drainage length, as well as the shearing strength properties of the foundation material. Finally, during pullout, volume change characteristics of the surrounding soils may change the theoretical suction pressures. A review of the existing knowledge relating to the design and construction of suction caissons is presented in this paper along with the results of a laboratory study on model caissons in sand and clay. Test results indicate that the use of suction pressure for installation of caissons is a viable alternative to conventional methods. Suction was also shown to resist some axial tensile loads.Key words: suction, pile, bucket, foundation, anchor, capacity.
2
Nabeshima, Yasuyuki. "Installation and Lateral Resistance of Model Suction Caissons in Sandy Ground". Advanced Materials Research 1030-1032 (settembre 2014): 790–97. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.790.
Testo completoAbstract (sommario):
Suction caissons attract the attention as the foundation of offshore wind turbines. Installation and resistance behaviors of the suction caisson are important factors for the design of foundation. An installation behavior into sandy seafloor was discussed by using a model suction caisson and the failure surfaces in the aluminum rod mass, as the model ground, subjected to lateral force were compared. Consequently, the installation of model suction caisson into sandy sea depended on the permeability of sandy seafloor and lateral resistance of suction caisson depended on the dimension of suction caisson which affected on the shape of failure surface in the ground.
3
Wang, Mingyuan, Xiaoke Liu, Xinglei Cheng, Qun Lu, Jiaqing Lu e Miao Wang. "Penetration and Pullout Capacity of Low-Skirted Suction Caissons". Shock and Vibration 2021 (4 settembre 2021): 1–12. http://dx.doi.org/10.1155/2021/2263810.
Testo completoAbstract (sommario):
The bearing capacity of suction caissons is the key to the design of offshore structures. A new type of cross-shaped low-skirted suction caisson is invented to effectively improve the bearing capacity, considering inevitable “soil plug” phenomenon. The behaviors of penetration and pullout for new low-skirted suction caisson are investigated by performing model tests. A new formula for calculating the penetration resistance is suggested based on the limit equilibrium theory and the test data, which can consider the change of the lateral area of the suction caisson during penetration. The behaviors of low-skirted suction caisson under inclined loading are analyzed by carrying out finite element simulation. The effects of loading angles and loading positions on the ultimate bearing capacity and failure mechanism of low-skirted suction caissons are discussed. The research results can provide a reference for the design of suction bucket foundation for offshore structures.
4
Wang, He, Rui Wang e Jian-Min Zhang. "Solid-Fluid Coupled Numerical Analysis of Suction Caisson Installation in Sand". Journal of Marine Science and Engineering 9, n. 7 (26 giugno 2021): 704. http://dx.doi.org/10.3390/jmse9070704.
Testo completoAbstract (sommario):
Suction caissons are widely used foundations in offshore engineering. The change in excess pore pressure and seepage field caused by penetration and suction significantly affects the soil resistance around the caisson wall and tip, and also affects the deformation of the soil within and adjacent to the caisson. This study uses Arbitrary Lagrangian–Eulerian (ALE) large deformation solid-fluid coupled FEM to investigate the changes in suction pressure and the seepage field during the process of the suction caisson installation in sand. A nonlinear Drucker-Prager model is used to model soil, while Coulomb friction is applied at the soil-caisson interface. The ALE solid-fluid coupled FEM is shown to be able to successfully simulate both jacked penetration and suction penetration caisson installation processes in sand observed in centrifuge tests. The difference in penetration resistance for jacked and suction installation is found to be caused by the seepage and excess pore pressure generated during the suction caisson installation, highlighting the importance of using solid-fluid coupled effective stress-based analysis to consider seepage in the evaluation of suction caisson penetration.
5
Zhu, Bin, Jia-lin Dai, De-qiong Kong, Ling-yun Feng e Yun-min Chen. "Centrifuge modelling of uplift response of suction caisson groups in soft clay". Canadian Geotechnical Journal 57, n. 9 (settembre 2020): 1294–303. http://dx.doi.org/10.1139/cgj-2018-0838.
Testo completoAbstract (sommario):
This paper describes a program of centrifuge model tests on the uplift behaviour of suction caisson foundations. The parameters considered were the loading rate, caisson diameter (D), soil strength profile, and type of footing (i.e., mono-caisson and tetra-caissons group). The loading responses were examined in terms of total uplift resistance, suction beneath the caisson lid, and the vertical displacements of the caisson and at the soil surface. There exists a critical uplift displacement, approximately 0.02D and 0.01D for the mono-caisson and the tetra-caissons groups, respectively, at which a turning point can be identified in the load–displacement curve. This was found to be attributed to the adhesion on the caisson–soil interface reaching a peak response and then dropping. Of interest is that the tetra-caissons group exhibits much greater normalized uplift resistance than the mono-caisson group before reaching an uplift displacement of about 0.02D, suggesting superiority of the former in term of serviceability. However, a reversed trend was observed at greater displacement, and accordingly an empirical model was derived to quantify the shadowing effect of caisson groups. Regarding the cyclic response, several cycles of large-amplitude loading are sufficient to reduce the ultimate bearing capacity of caisson(s) to below the self-weight of the inner soil plug(s), indicating a transition of failure mechanism.
6
Zhou, Hongjie, e Mark F. Randolph. "Large deformation analysis of suction caisson installation in clay". Canadian Geotechnical Journal 43, n. 12 (1 dicembre 2006): 1344–57. http://dx.doi.org/10.1139/t06-087.
Testo completoAbstract (sommario):
Large deformation finite element (LDFE) analyses were performed to study the installation of caissons by suction and jacking in normally consolidated clay. The penetration of the caisson wall was modelled between depths of one and four diameters using an axisymmetric LDFE approach, which falls in the category of arbitrary Lagrangian–Eulerian (ALE) methods. The results allowed quantification of differences in the behaviour of caissons installed entirely by jacking compared with a combination of self-weight and suction as is used in the field. For jacked installation, over the penetration range of one to four diameters, the proportion of caisson wall accommodated by inward soil flow reduced from around 45% at the start to zero at about four diameters embedment; by contrast, the proportion for suction installation stayed essentially constant, oscillating around 65% through the depth of penetration. This difference was also evident in the local incremental displacements of the soil beneath the caisson tip. During continuous penetration, the induced increases in radial and mean total stresses around the caisson wall are some 10%–15% smaller for suction installation than for jacked installation, with the difference growing with increasing penetration. In addition, an obvious difference was found in the caisson tip resistance between these two installation methods.Key words: suction caisson, clay, large deformation finite element, soil plug, total stress changes, penetration resistance, factor of safety.
7
Shi, Ping. "Model Tests on Characteristic of Suction Caissons in Saturated Fine Sand Under Intermittent Loading". Polish Maritime Research 25, s3 (1 dicembre 2018): 127–35. http://dx.doi.org/10.2478/pomr-2018-0121.
Testo completoAbstract (sommario):
Abstract Suction caissons are often used for the caissons of both offshore oil platforms and offshore wind power projects because of their advantages of simple construction, economical cost, and reusability. In this study, model tests were conducted in sand in order to investigate the effects of the caisson installation method on the penetration depth and the critical suction. Results of the test program showed that the method of changing the frequency of suction during different stages of the process can increase the penetration depth of the caisson. Combining with the deformation of the soil body inside and outside the caisson, the existing method for calculating the critical suction is modified, and the critical suction calculation equation of the discontinuous penetration test is proposed. Based on the test results, the calculation equation of the soil heave height can be more accurate predicted. The analysis results verify that the calculation method and the actual results are in good agreement.
8
Xie, Liquan, Shili Ma e Tiantian Lin. "The Seepage and Soil Plug Formation in Suction Caissons in Sand Using Visual Tests". Applied Sciences 10, n. 2 (13 gennaio 2020): 566. http://dx.doi.org/10.3390/app10020566.
Testo completoAbstract (sommario):
The rapid development of offshore wind energy in China is becoming increasingly relevant for movement toward green development. This paper presents the results of visual tests of a suction caisson used as foundation for offshore wind turbines. The distribution of hydraulic gradients of sand at the mudline in the caisson was obtained to find out the relationship with the heights of soil plugs. The relationship equation was proposed and obtained by using quadratic regression, guiding project designs, and construction. It was found that there was no soil plug in the caisson when small suction was applied during the suction penetration. The relationship between the heights of the soil plugs and the hydraulic gradient of the soil was proposed and obtained by using quadratic regression to predict (roughly) the height of soil plugs in suction caissons in sand during suction penetration. The influence of settlement outside caissons on the soil plug was found to decrease as the buried depth rose.
9
Zhao, Zhifeng, Mi Zhou, Yuxia Hu e Muhammad Shazzad Hossain. "Behavior of soil heave inside stiffened caissons being installed in clay". Canadian Geotechnical Journal 55, n. 5 (maggio 2018): 698–709. http://dx.doi.org/10.1139/cgj-2016-0667.
Testo completoAbstract (sommario):
The length of suction caisson anchors has been increasing to support increasing dimensions and weight of floating facilities, which necessitates employing horizontal ring stiffeners at intervals along the inner wall of the thin skirt of caissons to ensure structural integrity. The addition of these stiffeners has created significant uncertainties regarding soil flow mechanisms, in particular soil heave inside the caisson, which may reduce the caisson final penetration depth and influence the process of installation due to the need to avoid inside soil suction in the pumping equipment. This paper reports results of large-deformation finite element (LDFE) analyses investigating soil heave inside stiffened caissons during installation in nonhomogeneous clay deposits, with the corresponding evolution of soil flow mechanisms and penetration resistance profiles reported by Zhou et al. in 2016. The LDFE analyses have simulated continuous penetration of stiffened caissons from the seabed surface. A detailed parametric study has been undertaken, exploring the relevant range of soil strength nonhomogeneity and normalized strength, stiffened caisson geometry, soil effective unit weight, and caisson roughness. Of particular interest is the influence of stiffeners on soil heave and potential penetration refusal. The results have been validated against previously published centrifuge test data in terms of soil heave and penetration resistance profile, with good agreement obtained. It is shown that the soil normalized strength at the mudline and its nonhomogeneity, caisson diameter relative to the sum of skirt thickness and stiffener width, and caisson penetration depth have significant influence on the inner soil heave and its profile across the caisson radius. An expression, based on the LDFE results is proposed to predict the maximum inner soil heave during installation of stiffened caissons in the field.
10
Jin, Shu Cheng, Yong Tao Zhang e Qi He Wu. "A Study on the Failure Mechanism of Suction Caisson under Vertical Load". Applied Mechanics and Materials 256-259 (dicembre 2012): 1985–89. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.1985.
Testo completoAbstract (sommario):
As a new type of deep water offshore foundation, suction caisson is widely used to offshore structures. However, the current methods of evaluation and design cannot meet the increasing requirement of engineering practice. In this dissertation, the studies are emphasized on finite element method for analyzing the suction caisson bearing capacity behavior and the failure mechanism under the vertical load. Based on studying the vertical bearing behavior of caissons with different ratio of length to diameter L / D, it shown that as L / D increases, the vertical bearing capacity growth slowed.
Tesi sul tema "Suction caisson"
1
Supachawarote, Chairat. "Inclined load capacity of suction caisson in clay". University of Western Australia. School of Civil and Resource Engineering, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0188.
Testo completoAbstract (sommario):
This thesis investigates the capacity and failure mode of suction caissons under inclined loading. Parametric finite element analyses have been carried out to investigate the effects of caisson geometry, loading angle, padeye depth (i.e. load attachment point), soil profile and caisson-soil interface condition. Displacement-controlled analyses were carried out to determine the ultimate limit state of the suction caissons under inclined load and the results presented as interaction diagrams in VH load space. VH failure interaction diagrams are presented for both cases where the caisson-soil interface is fully-bonded and where a crack is allowed to form along the side of the caisson. An elliptical equation is fitted to the normalised VH failure interaction diagram to describe the general trend in the case where the caisson-soil interface is fully-bonded. Parametric study reveals that the failure envelope in the fully-bonded case could be scaled down (contracted failure envelope) to represent the holding capacity when a crack is allowed to form. A stronger effect of crack on the capacity was observed in the lightly overconsolidated soil, compared to the normally consolidated soil. The sensitivity of caisson capacity to the changes in load attachment position or loading angle was quantified based on the load-controlled analyses. It was found that, for caisson length to diameter ratios of up to 5, the optimal centreline loading depth (i.e. where the caisson translates with no rotation) is in the range 0.65L to 0.7L in normally consolidated soil, but becomes shallower for the lightly overconsolidated soil profile where the shear strength profile is more uniform. The reduction of holding capacity when the padeye position is shifted from the optimal location was also quantified for normally consolidated and lightly overconsolidated soil profiles at loading angle of 30 [degrees]. Upper bound analyses were carried out to augment the finite element study. Comparison of holding capacity and accompanying failure mechanisms obtained from the finite element and upper bound methods are made. It was found that the upper bound generally overpredicted the inclined load capacity obtained from the finite element analyses especially for the shorter caisson considered in this study. A correction factor is introduced to adjust the upper bound results for the optimal condition. Comparisons of non-optimal capacity were also made and showed that the agreement between the upper bound and finite element analyses are sensitive to the change in the centreline loading depth when the caisson-soil interface is fully bonded, but less so when a crack forms.
2
El-Gharbawy, Sherif Lotfy. "The pullout capacity of suction caisson foundations /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Testo completo
3
Cotter, Oliver. "Installation of suction caisson foundations for offshore renewable energy structures". Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534163.
Testo completo
4
Dekker, Marijn Johannes. "The Modelling of Suction Caisson Foundations for Multi-Footed Structures". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-27161.
Testo completoAbstract (sommario):
Suction caissons are a type of offshore foundation that allow for fast and noise-free installation and decommissioning of offshore structures. They have been used for 20 years in the oil and gas industry and are also becoming more common in the offshore wind sector as a promising way to cost reduction. SPT is a leading contractor for the installation of both single anchor piles and foundations on multiple caissons. The suction caissons are installed by applying a differential pressure between the inner and outer sides of the caissons, which pushes the caissons into the soil. When a platform is founded on multiple suction caissons, the way the wind and wave loads are transferred through the structure and various caissons into the soil will depend on the stiffness of both the platform and the caissons. The design of the substructure and suction caissons should thus be combined to include the effects of soil-structure interaction. This is currently done by modelling the suction caisson foundations as a set of linear-elastic springs attached to the substructure. These springs are however not able to capture the non-linear behaviour that is often characteristic for soils. A method has been developed to model the suction caisson foundations using non-linear springs. The characteristics of the springs are determined using FEM calculations with a nonlinear soil model in the geotechnical software PLAXIS. The springs are then implemented in a structural model of the substructure and the multiple foundations in the structural software SACS. The resulting loads on and displacements of the suction caisson foundations for a test load case have been compared to results from a complete FE model and a model that uses linear-elastic springs. The comparison has shown that the developed model gives results that match well with the results from the full FE model. The linear-elastic model on the other hand gives results that deviate significantly for high loads.When the stresses in the soil increase the soil will behave softer, leading to an increase of the displacements of the suction caissons for high loads. The substructure will help decrease large differences between the displacements of the suction caissons, resulting in a more even load distribution over the foundations and thus smaller design loads for the suction caissons. This allows for smaller suction caissons and savings of material and costs. The model with nonlinear springs is able to predict this behaviour of the soil and the substructure accurately and can be used to make a more efficient design of suction caisson foundations.
5
Sharma, Partha Pratim. "Ultimate capacity of suction caisson in normally and lightly overconsolidated clays". Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/2460.
Testo completoAbstract (sommario):
Petroleum exploration and production in recent years have moved into increasingly deeper water off the continental shelf. Some of these facilities are anchored in water depths in excess of 1000 meters. Exploration and production in deep water present new technological challenges where traditional fixed platforms have given way to floating structures. Today suction caissons are the most commonly used anchorage system for permanent offshore oil production facility. The objective of this study is to numerically predict the ultimate capacity of suction caissons in normally consolidated and lightly overconsolidated clays. Representative soil profile from the Gulf of Mexico and the North Sea are taken and analyzed for suction caissons with length over diameter ratios of 2, 4, 6 & 8. Normalized failure load interaction diagrams are generated for each of the cases. The location of optimum attachment point is also reported for each of the cases. General purpose finite element computer program ABAQUS is used for the numerical prediction. The finite element study is carried out with three-dimensional models using hybrid elements. A simplified elastic perfectly plastic model with von-Mises yield criterion is used for the study. The saturated clay is treated as an incompressible material. Results of the study compares well with existing simplified method for estimating load capacity of suction caisson anchors.
6
Cox, James A. "Long-term serviceability behaviour of suction caisson supported offshore wind turbines". Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680352.
Testo completoAbstract (sommario):
Suction caissons have recently been considered as an alternative to monopile foundations for offshore wind turbines and met masts. By their nature, such structures have stringent limit states imposed on their design dictating the first modal frequency and the allowable structural rotations. The aim of this thesis is to assess how cyclic loading will affect the long-term serviceability behaviour of such an offshore structure. The behaviour of such a representative caisson system was assessed through the use of a series of scale model tests conducted in dry sand, replicating a fully drained prototype condition. These tests were designed to record the foundation stiffness, its evolution under cyclic loading, how the system accumulates rotation with loading cycles and the dynamic properties of a caisson system. This was conducted at a number of scales under single-g and multi-g conditions. Considering all of the experimentally obtained data it was possible to analyse and provide a prediction as to the long-term behaviour of such an offshore structure. It was discovered that the foundation stiffness was highly dependent on the strain level and under the application of cyclic loading the stiffness would tend to increase in a logarithmic manner. In addition it was found that when subjected to a cyclic load a caisson system will accumulate rotation in accordance with a power relationship. Finally the dynamic properties were found to closely match pre-existing formulations describing a simple dynamic system. Considering these results it was possible to produce an analytical model to describe the evolution of serviceability of a caisson founded offshore structure. Latterly this model was applied to a series of representative cyclic loading test to examine the validity of the complete model.
7
Chen, Wen. "Uniaxial behaviour of suction caissons in soft deposits in deepwater". University of Western Australia. School of Civil and Resource Engineering, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0136.
Testo completoAbstract (sommario):
Suction caissons are a cost-effective alternative to traditional piles in deep to ultradeep waters. No design rule has been available on the axial capacity of suction caissons as part of the mooring system in soft sediments. In this research, a series of centrifuge tests were performed using instrumented model caissons, to investigate the axial capacity and radial stress changes around caissons during installation, consolidation and vertical pullout in normally consolidated, lightly overconsolidated and sensitive clays. Total pressure transducers instrumented on the caisson wall were calibrated for various conditions. The radial total stress acting on the external wall varied almost linearly during penetration and extraction of the caisson, with smaller gradients observed during post-consolidation pullout. Minimum difference was found in the penetration resistance and the radial total stress for caissons installed by jacking or by suction, suggesting that the mode of soil flow at the caisson tip is similar under these two types of installation. Observed soil heave showed that the soil particles at the caisson tip flow about evenly outside and inside the caisson during suction installation. Comparison was made between measurements and various theoretical predictions, on both the radial stress changes during caisson installation, and the radial effective stress after consolidation. Significant under-predictions on excess pore pressure changes, consolidation times and external shaft friction ratios were found for the NGI Method, based on the assumption that the caisson wall is accommodated entirely by inward motion of the clay during suction installation. Obvious over-predictions by the MTD approach were found in both stress changes and shaft capacity of the caissons. A simple form of cavity expansion method was found to give reasonable estimations of stress changes and post-consolidation external shaft friction. A model for predicting the penetration resistance of suction caissons in clay was evaluated. Upper and lower bound values of external shaft friction ratio during uplift loading after consolidation were derived. Uplift capacity of caissons under sustained loading and cyclic loading were investigated, revealing approximately 15 to 30% reduction of the capacity compared to that under monotonic loading. External shaft friction ratios and reverse end-bearing capacity factors were both found to be significantly lower than those under monotonic loading
8
Mucolli, Gent. "Fuzzy modeling of suction anchor behavior based on cyclic model tests data". Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/1313.
Testo completoAbstract (sommario):
This paper proposes a novel model that can predict the displacement of suction caisson anchors under monotonic and cyclic loading. Failure is assumed to occur when the accumulative monotonic and cyclic displacement along the load attachment point is over 60% of the diameter of the anchor. The anchors will go through lateral failure when the accumulative monotonic and cyclic displacement along the loading direction at the load attachment point is over 30% of the diameter. Hence, it is important to predict this displacement and therefore determine the expected failure of the anchor. However, it is difficult to predict displacement using the modern software without knowing the material properties of the soil and piles. Hence a new model that relies only on the normalized static load (Fa/Ff), normalized cyclic load (Fcy/Ff ), loading angle (Θ), and the number of cycles (N) is proposed. The inputs for training of the proposed model are (Fa/Ff), (Fcy/Ff), (Θ), (α) and (N). The output of the model will be the displacement normalized by the diameter of the anchor. To generalize the trained model, unused sets of data are used to validate the model. Furthermore, a comparative study is performed to evaluate the effectiveness of the proposed model. It is shown from extensive simulation that the model can accurately predict the normalized displacement of suction caisson anchors.
9
Senders, Marc. "Suction caissons in sand as tripod foundations for offshore wind turbines". University of Western Australia. School of Civil and Resource Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0163.
Testo completoAbstract (sommario):
[Truncated abstract] The demand for offshore wind turbines is increasing in densely populated areas, such as Europe. These constructions are typically founded on a gravity foundation or a large 'mono pile'. Gravity foundations can only be used at locations where strong soils exist and water depths are limited. Costs associated with a 'mono pile' type foundation contribute to a very large percentage of the total investment costs. This research, therefore, focuses upon a different foundation for offshore wind turbines, namely suction caissons beneath a tripod. This foundation can be used in all kinds of soil types and is cheaper than the 'mono pile' foundation, both in the amount of steel used and installation costs. Cheaper foundations can contribute to a more competitive price for offshore wind energy in comparison with other energy resources. To date, there have been relatively few studies to investigate the behaviour of this type of foundation during the installation process and during operational and ultimate loading for seabed conditions comprising dense sand. Two types of investigations were performed during this research to determine the behaviour of suction caissons beneath a tripod. Firstly, an existing computer program was extended to predict the typical loading conditions for a tripod foundation. Secondly, centrifuge tests on small scale suction caissons were performed to investigate the behaviour during the installation and loading phases. The computer program developed helped to quantify the likely ranges of environmental loading on an offshore wind turbine. For a typical 3 MW wind turbine of 90 m height, the vertical load is low at around 7 MN. During storm conditions the horizontal hydrodynamic load can be in the order of 4 MN. During normal working conditions the horizontal aerodynamic loads can reach 0.4 MN, but can increase to 1.2 MN when the pitch system malfunctions and gusts reach 30 m/s. This aerodynamic load will result in a very large contribution to the overturning moment, due to the high action point of this load. When the wind turbine is placed on top of a tripod, these large moments are counteracted by a push-pull system. ... The development of differential pressure was found to depend on the soil permeability, the extraction speed and a consolidation effect. During cyclic loading no obvious signs of a decrease in resistance were observed. During very fast cyclic loading differential pressures developed, which could increase the drained frictional resistance by approximately 40%. All centrifuge tests results were used to develop methods to predict or back calculate the installation process of suction caissons in sand and layered soil, and the behaviour during tensile and cyclic loading. These methods all use the cone resistance as the main input parameter and predict the force (or required suction) as a function of time, for a given rate of pumping or uplift displacement, in addition to the variation of suction with penetration (or force with uplift displacement). These new methods provide a useful tool in designing a reliable foundation for offshore wind turbines consisting of a tripod arrangement of suction caissons embedded in dense sand.
10
Cauble, Douglas Frederick. "An experimental investigation of the behavior of a model suction caisson in a cohesive soil". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10734.
Testo completoCapitoli di libri sul tema "Suction caisson"
1
Harte, Michael, e Avi Shonberg. "Reliability Based Installation Design of a Suction Caisson in Clay". In Lecture Notes in Civil Engineering, 376–82. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2306-5_52.
Testo completo
2
Stapelfeldt, M., B. Bienen e J. Grabe. "Insights into Suction Caisson Installation Utilising the Material Point Method". In Challenges and Innovations in Geomechanics, 802–9. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64514-4_86.
Testo completo
3
Mehravar, M., O. Harireche e A. Faramarzi. "Geotechnical Performance of Suction Caisson Installation in Multi-layered Seabed Profiles". In Springer Series in Geomechanics and Geoengineering, 467–74. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99670-7_58.
Testo completo
4
Shen, Kanmin, Zhen Guo, Lizhong Wang, Shengjie Rui e Ben He. "Investigation on Seepage Erosion and Safety Mechanism of Suction Caisson Installation". In Lecture Notes in Civil Engineering, 196–202. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2306-5_26.
Testo completo
5
Jasna, P. H., Beena Mary John e Rajesh P. Nair. "Comparative Study of Monopod and Tripod Suction Caisson Foundation for an Offshore Wind Turbine". In Lecture Notes in Civil Engineering, 355–63. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-80312-4_31.
Testo completo
6
Zhu, Wen-bo, Guo-liang Dai, Wei-ming Gong e Xue-liang Zhao. "Upper Bound Solution for Ultimate Bearing Capacity of Suction Caisson Foundation Based on Hill Failure Mode". In Springer Series in Geomechanics and Geoengineering, 463–66. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-97112-4_104.
Testo completo
7
Patel, Suchit Kumar, e Baleshwar Singh. "A Study on the Vertical Pullout Capacity of Suction Caisson Foundation in Sandy and Clayey Soils". In Lecture Notes in Civil Engineering, 367–77. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-2260-1_36.
Testo completo
8
Jia, Junbo. "Suction Piles/Caissons". In Soil Dynamics and Foundation Modeling, 655–68. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-40358-8_26.
Testo completo
9
Sekar, Preethi, N. Preetham Rajan e Satya Kiran Raju Alluri. "Analysis of Suction Caissons in Soft Clay". In Lecture Notes in Civil Engineering, 505–16. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6370-0_45.
Testo completo
10
Clukey, E. "Suction caisson soil displacement during installation". In Frontiers in Offshore Geotechnics. Taylor & Francis, 2005. http://dx.doi.org/10.1201/noe0415390637.ch17.
Testo completoAtti di convegni sul tema "Suction caisson"
1
Nabipour, Mahmood, Mostafa Zeinoddini e Mahmood R. Abdi. "Failure Modes of Tapered Suction Caissons Under Vertical Pull-Out Loads". In ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29490.
Testo completoAbstract (sommario):
The pull-out performance of conventional upright suction caissons has been investigated by different researchers. However, no attention has been formerly paid to tapered suction caissons. Some numerical studies already conducted by the authors demonstrated that tapered caissons exhibit pull-out capacities well above than that from their corresponding upright caissons. This paper deals with different failure mechanisms of tapered suction caissons and discusses some reason for their superior performance. A numerical approach has been used and different combinations of caisson types/ soil categories have been examined. With tapered suction caissons two different modes of failure have been discerned. The first mode has been noticed to develop in weak clays and sands under drained conditions. This mode corresponds to a shear sliding failure in the soil plug along the caisson’s interior wall. Concurrently a soil wedge is formed in the soil body adjacent to the caisson. The second mode of failure has been observed in higher strength drained clays and undrained clays and sands. With this failure mode a local failure at the bottom of the soil plug has been noticed to happen. At the same time the failure is extended to the lower surfaces of a soil wedge outside of the caisson. The detached soil plug accompanies the caisson in its movement upward following the local failure.
2
Zeinoddini, Mostafa, Mahmood Nabipour e Mahmood R. Abdi. "Modes of Failure for Suction Caissons Under Vertical Pull-Out Loads". In 25th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/omae2006-92239.
Testo completoAbstract (sommario):
Suction caissons have a fair base in the offshore industry, however, prediction of their behaviour and capacities still need extra attentions. Understanding their modes of failure is crucial for any analytical solutions. In this paper, failure mechanisms noticed in a numerical study of the suction caissons behaviour under vertical pull-out loading are reported. The employed finite element models have been calibrated by and verified against different available experimental data. In principal four distinctive modes of failure have been recognized. The first mode corresponds to a shear sliding failure in the soil plug along the caisson’s wall interior. This mode of failure has been mainly found in drained but comparatively weak soils. The second mode of failure noticed under drained conditions in soils with enhanced strength characteristics is a local tension failure occurring in the bottom of the soil plug. In this case the detached soil plug accompanies the caisson in its movement upward. The third mode corresponds to a restricted shear failure outside the caisson. It develops to a local wedge initiating halfway through the caisson walls and extending out to the soil surface. This failure mode has been mostly noticed with clays under undrained conditions. The foruth mode has been found to be a general shear failure in the soil underneath and around the caisson. It occurs in a wider spread body of the soil and has been noticed with the undrained sands. The load-displacement curves present a virtually bi-linear behaviour.
3
Luke, Adam M., Alan F. Rauch, Roy E. Olson e Elliott C. Mecham. "Behavior of Suction Caissons Measured in Laboratory Pullout Tests". In ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37023.
Testo completoAbstract (sommario):
Laboratory experiments are being conducted to study the behavior of suction casissons used for deep offshore moorings. Tests with a 100-mm diameter by 910-mm long caisson prototype, which is installed using dead weight or suction, are performed in a 1.1-m thick deposit of normally consolidated kaolinite. Instrumentation is used to record displacements, axial forces, and pore water pressures (at five locations along the interior and exterior surfaces of the caisson) during extraction of the caisson. Axial pullout tests have been conducted on caissons inserted using dead weight only or dead weight plus suction pressure, on caissons pulled with a vented or sealed top cap, and with rapid (undrained) versus slow (drained) pullout. Measured pullout capacities are interpreted in terms of the weight of extracted soil, side resistance on the caisson walls, and the reverse end bearing capacity at the tip.
4
Maniar, Dilip R., Luis F. G. Va´squez e John L. Tassoulas. "Installation and Pullout of Suction Caissons: Finite-Element Simulation". In ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37501.
Testo completoAbstract (sommario):
This paper reports on the development of computational tools at the Offshore Technology Research Center to study the behavior of suction caissons also known as suction anchors and bucket foundations. The effects of installation on axial capacity are examined through simulation of caisson penetration into clayey soil by self-weight and suction. A frictional contact algorithm based on a slide-line formulation is used to analyze interaction between the caisson and the surrounding soil during installation. The contact formulation allows large relative displacement between the caisson and the soil. In addition, a remeshing tool eliminates the need for a priori specification of the caisson penetration path: as installation of the caisson progresses, the finite-element mesh is adjusted so that the line of nodes below the caisson tip remains straight in the axial direction. An overview of the computational procedure along with results obtained from simulation of caisson installation, reconsolidation of the soil-skeleton and caisson pullout is presented. The computational results are compared with measurements from laboratory tests also conducted at the Offshore Technology Research Center.
5
Tran, Manh N., Mark F. Randolph e David W. Airey. "Experimental Study of Suction Installation of Caissons in Dense Sand". In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51076.
Testo completoAbstract (sommario):
Physical models have been developed to investigate suction installation of caisson foundations in fine-grained dense silica sand. The main controlling factor, pumping rate, was found to have significant influence on the differential pressure result across the caisson base. Rapid pumping is unlikely to bring any adverse effect to the installation process, even applied at very shallow initial wall penetration depth. Quick installation, with the exception of caissons with wall-to-diameter (t/D) ratio larger than 1%, appeared to be beneficial in reducing the excessive sand heave. Observations showed that caisson geometry and surcharge also affected the installation performance. Although requiring only marginal increase in suction pressure to install, caissons with thicker walls created substantially higher sand heave during installation. Varying the absolute caisson size did not seem to affect the suction pressure for a given t/D. Seepage flow was also calculated during each test, and found to increase with deeper skirt penetration.
6
Zeinoddini, Mostafa, Woorya H. Shariati e Mahmood Nabipour. "Numerical Investigation Into Parameters Influencing the Installation of Suction Caissons in Sand". In ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/omae2008-57584.
Testo completoAbstract (sommario):
This paper reports results from a numerical investigation into the suction caissons penetration in sand. Two dimensional axisymmetric models have first been calibrated and verified against several laboratory and field test data from other researchers. Soil nonlinearities and soil/caisson interactions have been taken into account. The verified models have then been used to evaluate the effects from various soil/structure characteristics on the performance of the suction caissons during the installation phase in sand. The results of the current study show that the total installation force required for the full penetration of the caisson has a second order relationship with the soil/caisson interface strength reduction factor. The soil cohesion has also been found to have a second order effect on the total installation force. The soil internal friction angle, and the soil modulus of elasticity have each been noticed to present an increasing linear effect on the total installation force. It has also been observed that while the caisson diameter remains constant, with an increase in the caisson length the total installation force almost linearly increases. This is the same when the caisson length is kept constant but its diameter increases. Dilatancy angle and Poisson’s ratio have been realized to have a second order monotically increasing effect on the total installation force.
7
Kennedy, Justin, John Oliphant, Alasdair Maconochie, Bruno Stuyts e David Cathie. "CAISSON: A Suction Pile Design Tool". In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10836.
Testo completoAbstract (sommario):
The two main suction pile design methods that are generally applied and accepted within the industry are 3D Finite Element analysis and limit equilibrium. The limit equilibrium method involves assuming a number of failure mechanisms with the mechanism offering the least resistance adopted for design. The limit equilibrium suction pile design software CAISSON has been developed and validated by Cathie Associates for Technip. It is currently in use for rapidly and reliably determining the critical failure mechanism and ultimate holding capacity of initiation, mooring and hold back suction piles in clay. CAISSON has been developed as a stand-alone program written in Visual Basic with a user-friendly program interface implemented to allow for efficient computations. The failure mechanisms employed in CAISSON were identified initially using 2D FE results from PLAXIS. The failure mechanisms identified were further calibrated using 3D FE modelling in ABAQUS and FLAC to account for the influence of side shear within the limit equilibrium equations adopted in CAISSON. The current version of CAISSON can analyse suction piles with L/D aspect ratios from 0.5 to 5 installed in clay of uniform or linearly increasing undrained shear strength. Additional program features include computation of inverse catenary shapes for anchor chains, anisotropic undrained shear strength profiles, pile tilt and pile misalignment. The development and validation of CAISSON is presented in this paper along with a case study and a short parametric study to identify the significance of the CAISSON input parameters that govern the ultimate holding capacity of suction piles. Planned upgrades to CAISSON will also be presented.
8
Aubeny, Charles P., Seungwoon Han e J. Don Murff. "Refined Model for Inclined Load Capacity of Suction Caissons". In ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37502.
Testo completoAbstract (sommario):
Suction caissons used as mooring anchors for offshore structures can, depending on design concept, be subjected to pullout forces ranging from nearly vertical for tension leg platforms, to intermediate inclination angles for taut mooring systems, to nearly horizontal for catenary moored systems. Hence, the ability to understand and predict suction anchor pullout resistance for a full range of load orientations is becoming of increasing importance. A previous paper by the authors presents a plastic limit analysis for estimating the load capacity of suction anchors over a full range of load inclination ranging from horizontal to vertical. The model was capable of predicting load capacity for various load attachment (padeye) depths, caisson aspect ratios, and soil undrained strength profiles that vary linearly with depth. Loading conditions are assumed to be undrained; therefore, a purely cohesive soil is assumed. The original analysis assumed full adhesion on the boundaries of the caisson; i.e., a skin resistance coefficient α equal to unity. However, actual values of this coefficient are less than unity, with specific values varying according to soil conditions and the method of caisson installation. To overcome the limitation of the original model, this paper presents a modified formulation that allows a skin resistance less than unity. The modified formulation develops an interaction relationship between vertical and horizontal soil resistance on the sides of the caisson that is applicable for any skin resistance conditions ranging from no to full adhesion.
9
Valle-Molina, Celestino, Ernesto Heredia-Zavoni e Francisco L. Silva-Gonza´lez. "Reliability Analyses of Suction Caissons for FPSO Systems". In ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/omae2008-57140.
Testo completoAbstract (sommario):
The reliability formulation for the analyses of suction caissons subjected to environmental loadings from FPSO systems is presented in this paper. The capacity model for the suction caisson assumes normally consolidated clays with a linear variation on the undrained shear strength. The limit equilibrium method was used to assess the inclined capacity of suction caissons. The probabilistic characterization of the environmental loading is associated to deep water sites in the Bay of Campeche in the Gulf of Mexico. The reliability of the suction caissons was performed by means of Monte Carlo simulations and calibration of partial safety factors was carried out for the ultimate limit state using the design equation proposed by DNV [1].
10
Zeinoddini, Mostafa, e Mahmood Nabipour. "Numerical Investigation on the Pull-Out Behaviour of Suction Caissons in Clay". In 25th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/omae2006-92058.
Testo completoAbstract (sommario):
Since their inception suction caisson foundations have presented themselves as proven means of anchoring floating production systems and fixed offshore structures. The pull-out capacity of suction caissons remains a critical issue in their applications, and in order to produce effective designs, reliable methods of predicting the capacity are required. In this paper results from a numerical investigation on the behaviour of the suction caissons in clays against pull-out loading have been presented. Soil nonlinearities, soil/caisson interactions and the effects from the suction on the behaviour have been taken into account. A linear relationship has been observed between the soil cohesion values and the pull-out capacity. Under drained conditions, beyond specific limits of soil cohesion values, the increase in the cohesion value have found to demonstrate no further influence on the pull-out capacity. The soil internal friction angle has been noticed to have an exponential increasing effect on the pull-out capacity. With constant values of the caisson diameter, an increase in the aspect ratio noticed to have a second order effect of the friction originated part and a linear influence on the cohesion originated part of the resistance. With constant values of the caisson length, an increase in the aspect ratio values has found to result in an exponential decrease of the pull-out capacity. Based on the obtained numerical results simple formulations and approximations have been proposed in order to estimate the effects of the studied parameters on the pull-out capacities.