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Littérature scientifique sur le sujet « FLOATING COLUMNS »

Auteur : Grafiati

Publié le 11 septembre 2023

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Articles de revues sur le sujet "FLOATING COLUMNS"

Singh, S. K., Sarv Priya, Mohd Nadeem et Md Badar Alam. « Analysis of G+5 Storeys Building With and Without Floating Column ». IOP Conference Series : Earth and Environmental Science 889, n^o 1 (1 novembre 2021) : 012008. http://dx.doi.org/10.1088/1755-1315/889/1/012008.

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Abstract In current period, several structures are being planned and built with structural complicatedness like building with floating columns on different floors and spaces. The buildings accompanying floating columns are extremely detrimental that is constructed in earthquake-prone regions. The current study analyses and compare the buildings with and without of floating column. The columns which are directly supported by a beam without any rigid base are known as floating columns. Various buildings have been constructed with floating columns in India. Typically, it is required to provide larger spacing between the columns to entertain the requirements of parking or reception lobbies. Some of the functional requirements of a building might be satisfied by providing the floating columns but the structural behaviour of the building changes abruptly. The beams that supported the floating columns require more flexure and shear demand than the surrounding beams. In addition, it leads to stiffness unevenness at a specific joint. Columns are the main structural elements that resist the lateral load in a rigid frame and have the importance in the performance of the building under earthquake load The storey’s stuffiness below the floating column is normally reduced. Therefore, an attempt has been made to analyse the performance of a G+5 storey building with and without floating columns and compare structural parameters such as horizontal displacement, storey drift and storey shear under seismic excitation using (ETABS) Software.

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Gajbhiye, Akshay. « Comparative Study of RC Multistorey Building with Floating Column and Shear Wall Subjected To Seismic Load ». International Journal for Research in Applied Science and Engineering Technology 9, n^o 9 (30 septembre 2021) : 528–35. http://dx.doi.org/10.22214/ijraset.2021.38011.

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Abstract : In modern multistorey building construction, irregularities like the soft storey, vertical and plan irregularities, floating columns etc are very common. Building with an open ground storey for parking is a common feature that results in floating columns. Floating columns provide column free space and a good aesthetic architectural view of the building. floating column means the end of any vertical element that rests on the beam which leads to discontinuity of columns such that the path of load distribution in multi-storey buildings is disturbed. The use of a floating column also tends to increase the moment in the column, storey shear etc which highly undesirable in seismically active areas. So, the study of the best location where the floating column needs to be provided to reduce the impact due to seismic loads is of primordial importance. Shear wall is a vertical member which is provided from foundation to top storey. In this study shear wall is used in the direction of orientation so that it provides additional strength and stiffness to the buildings. In the present analysis, 8 models are studied. The first model considers a multi-storeyed building without any shear wall and floating column. Other models analysed are with shear wall and by varying the location of floating columns. The analysis and design are done by STAAD.pro V8i SS6 version software and the method used is response spectrum analysis in earthquake zone 4. The effect of floating column location on parameters such as Base shear, Displacement, Maximum moment, storey shear and percentage of steel reinforcement are discussed. The comparison of results of different models is also carried out in detail using graphs and bar charts in this study. The suitable location for providing a floating column with the shear wall is also discussed. Keywords: Floating column, Shear wall, Seismic load, STAAD.pro.v8i, Response Spectrum Analysis.

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Lallawmkimi et Dr Pankaj Kumar. « Effect of Floating Column in High Rise Building : A Review ». International Journal of Innovative Technology and Exploring Engineering 12, n^o 6 (30 mai 2023) : 51–55. http://dx.doi.org/10.35940/ijitee.f9557.0512623.

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The usage of floating columns for additional space is a recent trend that caters to functional needs. The architectural feature known as the floating column responds poorly to earthquakes. As a result, it should be avoided in areas prone to earthquakes. Earthquakes affect mostly where there is a weak structure; in modern buildings, apertures are widespread for lifts, lighting, and other architectural features. This review displays the results of numerous research studies. Different researchers used various floating column locations across the structure. The main goal of research conducted by various researchers is to compare structures with floating columns and without floating columns. The evaluation is done to see if the building is on the side that is safer or if it is subjected to lateral effects. This review on floating columns examines the behavior and impact on the structure as well as possible mitigation measures.

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Chouhan, Rahul, et Mayur Singi. « Study on Reinforced Concrete Building with and without Floating Column Configurations under Earthquake Loading ». International Journal for Research in Applied Science and Engineering Technology 11, n^o 7 (31 juillet 2023) : 870–79. http://dx.doi.org/10.22214/ijraset.2023.54755.

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Abstract: In the present scenario, due to a lack of available space and an increase in population, open space is typically designated on the bottom level of multi-story buildings (both residential and commercial) for parking, gathering spaces, or theatre uses in the current situation. Floating columns were developed to meet the demand for big open areas with little or little usage of columns. Columns without a foundation are known as floating columns since they rely on beams. Since these columns provide a continuous channel for weight transmission, they are regarded as being unstable during an earthquake. Throughout the study, multiple writers examine various floating column designs. For various seismic zonal zones, their impact on the structure is compared to structures without floating columns, and the safest arrangement is determined.

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Al-Auqbi, Sura Tawfeeq, Nahla M. Salim et Mahmood R. Mahmood. « The Impact of Using Different Types of Soft Soils Treated by Stone Columns on Creep Behavior ». IOP Conference Series : Earth and Environmental Science 961, n^o 1 (1 janvier 2022) : 012052. http://dx.doi.org/10.1088/1755-1315/961/1/012052.

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Abstract The stone column technique is an effective method to increase the strength of soft cohesive soil, which results in a reduction in foundation settlement and an increase in bearing capacity. The topic of restraining creep settlement through the use of stone columns techniques has gained increasing attention and consideration; because stone columns are widely used to treat soft soil deposits, caution should be applied in estimating creep settlement. We discovered a reversible relation between shear parameters and the creep settlement in floating stone columns; while, in case of end-bearing stone columns shows a direct positive relation between shear parameters and the creep settlement, and the creep settlement began at the primary settlement. The shear parameters affected the improvement factor (n) of creep settlement in both floating and end-bearing stone columns. The standard creep coefficient’s n values in floating and end-bearing conditions were more significant than the low creep coefficient’s n values in forwarded geometric conditions. The stress in both floating and end-bearing stone columns was increasing and uniformly distributed along the length of the floating stone column and in the case of end-bearing stone column was limited to the stiffness layer; the maximum vertical stress was in the central point of the embankment. The embankment’s maximum horizontal displacement occurred on the edge.

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Dash, Sujit Kumar, et Mukul Chandra Bora. « Influence of geosynthetic encasement on the performance of stone columns floating in soft clay ». Canadian Geotechnical Journal 50, n^o 7 (juillet 2013) : 754–65. http://dx.doi.org/10.1139/cgj-2012-0437.

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This paper investigates the influence of geosynthetic encasement on the performance of stone columns floating in soft clay. It was found that with unencased columns the bearing capacity improvement is about 3.5 fold, but with geogrid encasement the improvement increases to 5 fold, where 60% of the column length is encased. With full-length encasement (i.e., 100%), the improvement is only about 3 fold. It is therefore evident that partially encased floating columns are superior to the fully encased ones. In contrast, with end-bearing stone columns, full-length encasement is reported to have exhibited better performance improvement than the partially encased ones. In the former case (floating columns), it is the bulge formation at a deeper depth that enhances the bearing capacity, while in the latter case (end-bearing columns), it is the stiffening effect of the encasement that enables the column to transmit the surcharge pressure onto the competent strata below.

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Karkush, Mahdi O., et Anwar Jabbar. « Improvement of Soft Soil Using Linear Distributed Floating Stone Columns under Foundation Subjected to Static and Cyclic Loading ». Civil Engineering Journal 5, n^o 3 (19 mars 2019) : 702. http://dx.doi.org/10.28991/cej-2019-03091280.

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A stone column is one of the soil improvement methods that are mainly used for improving the geotechnical behavior of soft soils. For deep improvement of soft soil, the floating stone columns are considered the best and effective economically which provide lateral confinement and drainage and longitudinal skin friction. In this study, six tests were carried out on the natural soft soil of undrained shear strength of 5.5 kPa improved by single and two linear distributed floating stone columns. The stone column dimensions are 30 mm in diameter and 180 mm in length and the stone column material is sand of high internal friction angle of 48°. The natural and improved soil samples are tested under isolated raft foundation of dimensions 120×120 mm subjected to vertical static and cyclic loading of frequency 2Hz and continued for 50 seconds. The results showed a significant improvement in soil bearing capacity when reinforced with stone columns despite the small area replacement ratio, where the bearing capacity of improved soil increased by 120 to 145%. The compressibility of improved soil decreased by 57 to 86% in comparison with that of natural soft soil. Also, the floating stone columns reduced the porewater pressure, where the stone columns considered efficient in providing short drainage pathways. This can be one of the reasons why soil reinforced with floating stone columns hold higher cyclic and static stresses regardless the end bearing of stone columns.

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Mahajan, Varun. « Dynamic Behaviour Comparison of an Irregular Edifice with Different Locations of Floating Column and Shear Wall ». International Journal for Research in Applied Science and Engineering Technology 9, n^o 12 (31 décembre 2021) : 1279–82. http://dx.doi.org/10.22214/ijraset.2021.39507.

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Abstract: Architects nowadays develop attractive edifices, and floating columns are widely employed in this process. Floating columns are used not only to provide a magnificent perspective but also when a vast open area is necessary. Edifices with irregular configurations are more vulnerable to earthquakes and hence, suitable shear wall placement is required to ensure the edifice's stability. Many multi-storey edifices collapsed in seconds after the Bhuj Earthquake (Jan 26, 2001), due to the presence of soft stories, floating columns, and mass anomalies. As a result, knowing the seismic reactions of these buildings are vital for constructing earthquake-resistant assemblies. The relevance of a Floating Column and the existence of a shear wall in an irregular multistorey building is highlighted in this study. Dynamic seismic behaviour of a G+18 irregular edifice with different locations of the floating column and different positions of the shear wall is explored in this research. The edifice is analysed and compared with the model without shear walls and floating columns to examine the alterations. The dynamic analysis is carried out using Response Spectrum Analysis and storey drift, storey displacement and base shear are calculated and finally, software compression is computed for different zones. The analysis is carried out by Indian standardized codes IS 1893:2016 and IS 456:2000 which are the codes specified by the Bureau of Indian Standards for earthquake resistance edifice design and plain and reinforcement concrete design respectively. Keywords: Floating Column, Shear Wall, Irregular Edifice, Seismic behaviour, Response Spectrum Analysis, storey drift, storey displacement, base shear.

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Patange, Ms Shivani, Dr R. K. Jain et Mrs Girija Deshpande. « Seismic Analysis of a Floating Column with Two Different Position of Building Using Software’s ». International Journal for Research in Applied Science and Engineering Technology 11, n^o 2 (28 février 2023) : 1348–53. http://dx.doi.org/10.22214/ijraset.2023.49188.

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Abstract: In present scenario buildings with floating columns is typical features in the modern multi-storey construction in urban India. Such features are highly undesirable in building built in seismically active areas. This study highlights the importance of explicitly recognising the presence of the first storey and the storey above, are proposed to reduce the irregularity introduced by the floating column. The behaviour of concrete structures is more vulnerable with the effect of floating columns resulted in failure of structures and severe damaged. The present project work is to the find the severity and effect of floating columns on the parameters of support reactions, axial forces, displacements, shear forces and twisting moments. In this paper using 3D finite element method & Matrix Displacement method seismic analysis of floating column With two different position is done for a multi-storey building. The structural response of the building models with respect to, base shear and storey displacements is investigated. The analysis is carried out using software ETABS & STAAD-PRO

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Chmielewska, Iwona. « Bearing capacity of floating geosynthetic encased columns (GEC) determined on the basis of CPTU penetration tests ». Open Engineering 10, n^o 1 (14 juillet 2020) : 699–704. http://dx.doi.org/10.1515/eng-2020-0078.

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AbstractFloating geosynthetic encased columns (GEC) are an increasingly popular method of strengthening weak subsoil. Design of floating columns is a difficult and not fully recognized issue. This paper treats the floating GEC column as a special kind of “pile” and its bearing capacity is calculated using five selected methods for calculating the bearing capacity of piles based on CPTU penetration tests. The calculations were done on the basis of insitu tests carried out on one of the sections of the Bargłów Kościelny bypass. The paper contains a comparison of the bearing capacities of floating GEC columns calculated with different methods based on CPTU penetration tests.

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Thèses sur le sujet "FLOATING COLUMNS"

Sparrer, Wendelle Faith. « Implementation and Demonstration of a Time Domain Modeling Tool for Floating Oscillating Water Columns ». Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/101889.

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Renewable energy is a critical component in combating climate change. Ocean wave energy is a source of renewable energy that can be harvested using Wave Energy Converters (WECs). One such WEC is the floating Oscillating Water Column (OWC), which has been successfully field tested and warrants further exploration. This research implements a publicly accessible code in MatLab and SimuLink to simulate the dynamics of a floating OWC in the time domain. This code, known as the Floating OWC Iterative Time Series Solver (FlOWCITSS), uses the pressure distribution model paired with state space realization to capture the internal water column dynamics of the WEC and estimate pneumatic power generation. Published experimental results of floating moored structures are then used to validate FlOWCITSS. While FlOWCITSS seemed to capture the period and general nature of the heave, surge, and internal water column dynamics, the magnitude of the response sometimes had errors ranging from 1.5% −37%. This error could be caused by the modeling techniques used, or it could be due to uncertainties in the experiments. The presence of smaller error values shows potential for FlOWCITSS to achieve consistently higher fidelity results as the code undergoes further developments. To demonstrate the use of FlOWCITSS, geometry variations of a Backward Bent Duct Buoy (BBDB) are explored for a wave environment and mooring configuration. The reference model from Sandia National Labs, RM6, performed significantly better than a BBDB with an altered stern geometry for a 3 second wave period, indicating that stern geometry can have a significant impact on pneumatic power performance.
Master of Science
Renewable energy is a critical component in combating climate change. Ocean wave energy is a source of renewable energy that can be converted into electricity using Wave Energy Converters (WECs). One such WEC is the floating Oscillating Water Column (OWC), which has been successfully field tested and warrants further exploration. Floating OWCs are partially submerged floating structures that have an internal chamber which water oscillates in. The motions of the water displace air inside this chamber, causing the air to be forced through a high speed turbine, which generates electricity. This research develops a publicly accessible code using MatLab and SimuLink to evaluate the motions and power generation capabilities of floating OWCs. This code is then validated against physical experiments to verify its effectiveness in predicting the device's motions. This publicly accessible code, known as the Floating OWC Iterative Time Series Solver (FlOWCITSS), showed error ranging from 1.5 % - 37% for the most important motions that are relevant to energy harvesting and power generation. These errors could be caused by the numerical models used, or uncertainties in experimental data. The presence of smaller error values shows potential for FlOWCITSS to achieve consistently higher fidelity results as the code undergoes further developments. To demonstrate the use of FlOWCITSS, geometry variations of floating OWCs are explored.

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Sunnetcioglu, Emrah Mehmet. « A Laboratory Model Study On Settlement Reduction Ofstone Columns In Soft Clay ». Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614558/index.pdf.

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ABSTRACT A LABORATORY MODEL STUDY ON SETTLEMENT REDUCTION Effect OF STONE COLUMNS IN SOFT CLAY Sü
nnetcioglu, Mehmet Emrah M.Sc., Department of Civil Engineering Supervisor: Prof. Dr. Mehmet Ufuk Ergun August 2012, 177 pages An experimental study was conducted in order to examine settlement reduction ratios of footing supported by both floating and end bearing type of stone columns. For the floating types, tests were done with varying column lengths of one and two widths of footing (L=B,2B). Tests were conducted in 200 mm* 200 mm* 200 mm cubic loading tanks. The reinforcement effect was achieved by the installation of four stone columns with 20 mm diameter under 70 mm* 70mm model footing. Parameters such as area replacement ratio (a_s), loading plate dimensions, consolidation and vertical pressures applied, and the relative density (D_R) of the granular column were kept constant, the column length (L) was set as the only variable in the experimental tests conducted. In the tests, footing settlements together with subsurface settlements at depths equal to footing width (B) and two times the footing width (2B) were measured by specially designed telltales. The settlement reduction ratios both at surface and subsurface were evaluated in order to determine the effect of column length on settlement improvement. It has been found out that as the column length increases the settlement reduction ratios decrease for all depth intervals. However, there exists a threshold column length (L=2B), beyond which the composite ground demonstrates little settlement improvement.

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Patel, Dhara Yogendra. « Reflection ». Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/32832.

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â Reflectionâ is an experiment with what I call â symbolic architectureâ i.e. design where the features of the building have a profound meaning or a strong recall to some familiar aspect in our lives. It is a meditation center designed to rejuvenate visitors by providing an ideal environment to practice and teach meditation. The design is inspired by concepts of Hindu philosophy and each element of the building, the light, the materials, the water and the structure is likened to an element of the spiritual being that helps a meditator achieve a connection between the body and the soul.
Master of Architecture

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Tvare, Oyvind. « Fatigue Analysis of Column-Pontoon Connection in a Semi-submersible Floating Wind Turbine ». Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-27048.

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In a world with ever increasing energy demands, there is a need to find new ways to harvest renewable energy. Floating offshore wind turbines could be an important energy source in the future. To make this possible a better understanding of offshore wind turbines is essential. This thesis has dealt with fatigue associated challenges related to a column-pontoon connection in a semi-submersible floating wind turbine developed at CeSOS, NTNU.The specific design investigated in this report has a transition hull from the cylindrical column to the rectangular pontoon. A finite element model of the connection was available and revealed very high stress concentration at some areas. The sub-modeling technique was applied at two crucial areas for a detailed stress analysis. The design of the connection was changed in order to reduce the stress concentration.Fatigue analysis were carried out at the intersection between the midpoint at the upper hull of the pontoon and the transition piece. The same was done at 13 points along the weld between the hull of the transition piece and the hull of the column. Load time series from global dynamic response analysis from 13 sea states, representing wave and wind conditions at deep water in the North Sea with 0, 30, and 60 degree wave heading, were available and used in fatigue calculations. Load time series from -30 and -60 degree heading were created assuming symmetry around the vertical midplane of the structure. 10 one hour simulations of every sea state were used.Cumulative fatigue damage at all sea states and wave headings were calculated and compared using rainflow counting, an appropriate S-N curve and Miner's rule. Estimated time to failure is calculated assuming a constant wave heading over the lifetime of the structure. The estimated fatigue life is also determined for a combined wave heading. The combined wave heading corresponds to the column-pontoon connection where 0 degree heading is dominating.There will be a multiaxial stress state at the different hot spots. A simplified method for including the fatigue damage contribution from all the different stress components (stress parallel with the weld, stress normal to the weld and shear stress) is proposed. The method has large limitations, but is intended to be used when there is a close to linear relationship between the different stress components. This method has been used when predicting fatigue life at all hot spots and the results have been evaluated.Estimated fatigue life at the most critical hot spot is 1.9 years under a combined wave heading. Multiple hot spots have a fatigue life under 10 years. More design changes is needed to achieve acceptable fatigue life. The method proposed for including multiaxial fatigue effects show promising results at some hot spots. The accuracy depends on which hot spot is analyzed and wave heading.

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Crema, Ilaria [Verfasser], et Hocine [Akademischer Betreuer] Oumeraci. « Oscillating water column wave energy converters integrated in very large floating structures / Ilaria Crema ; Betreuer : Hocine Oumeraci ». Braunschweig : Technische Universität Braunschweig, 2018. http://d-nb.info/1175815357/34.

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Kuruoglu, Ozgur. « A New Approach To Estimate Settlements Under Footings On Rammed Aggregate Pier Groups ». Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609733/index.pdf.

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This study uses a 3D finite element program, calibrated with the results of a full scale instrumented load test on a limited size footing, to estimate the settlement improvement factor for footings resting on rammed aggregate pier groups. A simplified 3D finite element model (Composite Soil Model) was developed, which takes into account the increase of stiffness around the piers during the ramming process. Design charts for settlement improvement factors of square footings of different sizes (B = 2.4m to 4.8m) resting on aggregate pier groups of different area ratios (AR = 0.087 to 0.349), pier moduli (Ecolumn = 36MPa to 72MPa), and with various compressible clay layer strengths (cu = 20kPa to 60kPa) and thicknesses (L = 5m to 15m) were prepared using this calibrated 3D finite element model. It was found that, the settlement improvement factor increases as the area ratio, pier modulus and footing pressure increase. On the other hand, the settlement improvement factor is observed to decrease as the undrained shear strength and thickness of compressible clay and footing size increase. After using the model to study the behaviour of floating piers, it was concluded that, the advantage of using end bearing piers instead of floating piers for reducing settlements increases as the area ratio of piers increases, the elasticity modulus value of the piers increases, the thickness of the compressible clay layer decreases and the undrained shear strength of the compressible clay decreases.

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Ozkeskin, Asli. « Settlement Reduction And Stress Concentration Factors In Rammed Aggregate Piers Determined From Full- Scale Group Load Tests ». Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605153/index.pdf.

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Despite the developments in the last decades, field performance information for short aggregate pier improved ground is needed for future design and to develop a better understanding of the performance of the short (floating) aggregate piers. A full-scale field study was performed to investigate the floating aggregate pier behavior in a soft clayey soil. Site investigations included five boreholes and sampling, four CPT soundings, and SPT and laboratory testing. The soil profile consisted of 8m thick compressible clay overlying weathered rock. Four large plate load test stations were prepared. A rigid steel footing having plan dimensions of 3.0m by 3.5m were used for loading. Four 65cm diameter reaction piles and steel cross beams were used to load the soil in each station. First test comprised of loading the untreated soil up to 250 kPa with increments, and monitoring the surface settlements. Moreover, distribution of settlements with depth is recorded by means of deep settlement gages installed prior to loading. Other three tests were conducted on clay soil improved by rammed aggregate piers. In each station, seven stone columns were installed, having a diameter of 65cm, area ratio of 0.25, placed in a triangular pattern with a center to center spacing of 1.25m. The length of the columns were 3m, 5m in the two station resembling floating columns, and 8m in the last station to simulate end bearing columns to observe the level of the improvement in the floating columns. Field instrumentations included surface and deep settlement gages, and load cell placed on a aggregate pier to determine distribution of the applied vertical stress between the column and the natural soil , thus to find magnitude of the stress concentration factor, n , in end bearing and floating aggregate piers. It has been found that, the presence of floating aggregate piers reduce settlements, revealing that major improvement in the settlements takes place at relatively short column lengths. It has been also found that the stress concentration factor is not constant, but varies depending on the magnitude of the applied stress. The magnitude of stress concentration factor varies over a range from 2.1 to 5.6 showing a decreasing trend with increasing vertical stress.

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Akbar, Demiral Salih. « The Non-uniform Argon Dc Glow Discharge System Parameters Measured With Fast Three Couples Of Double Probe ». Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607109/index.pdf.

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The non-uniform dc glow discharge plasma system is studied by using isolated computer controlled three couples of double probe system (TCDP) in argon gas, simultaneously. TCDP system has been developed to use for magnetized, unmagnetized, and for low oscillating plasma systems by using low pass filter with optically isolated circuitry to minimize the measurement errors with higher resolution and accuracy. Difference in the shapes and diameters of the discharge tube from region to region leads to change in the positive column glow discharge properties. This is because the positive column inhomogeneities, rising from the increase in the electron densities at the small tube radius region than the large one. Therefore, the axial electric field and the electron temperature have been diverted from their normal behavior in the positive column. However, at the large radius regions, the axial electric field seams to stay approximately constant at higher discharge currents. On the other hand, In this work the radial dependence of the electron temperature, density, floating potential, and the normalized probe radius (&
#958
=rp&
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D) has been investigated. Since, the probe radius is smaller than Debye length, the orbital motion limited (OML) theory has been used. As a result, the electron temperature (at the center) decreased and density increased with decreasing tube radius, and they have maximum values at the first probe (near the cathode). The electron density ne was observed to decrease and electron temperature Te to increase with increasing the discharge current. The floating potential has less negative value with decreasing tube radius except at the higher currents. Finally, it has been found that the &
#958
is proportional with electron density, but it remains constant depending on the value of Te and ne.

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Coudurier, Christophe. « Conception, modélisation et contrôle d'un tube anti-roulis multidirectionnel pour une barge offshore portant une éolienne ». Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM054/document.

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Suite à la mise en place de politiques publiques favorisant les énergies renouvelables, la construction de fermes éoliennes offshore est en plein essor aux quatre coins du monde. Or, la technique de l'éolienne offshore posée, la seule utilisée actuellement, n'est pas viable économiquement dans des eaux trop profondes. Ceci représente un sérieux frein au développement de l'énergie éolienne. Pour cette raison, la communauté scientifique s'intéresse depuis plusieurs années aux éoliennes sur plates-formes flottantes. En eau profonde, cette technologie est intéressante. Mais le fait que l'éolienne ne soit pas encastrée au fond de la mer augmente très significativement les sollicitations mécaniques induites par les vagues.Pour réduire ces sollicitations qui ont de nombreux effets néfastes, différentes approches sont possibles. Essayer de compenser les oscillations « avant-arrière » du mât de l'éolienne en pilotant la force de poussée exercée au niveau du rotor a déjà été écarté dans la littérature. Nous nous sommes concentrés sur l'ajout d'un dispositif de stabilisation interne à la plate-forme, de type Tuned Liquid Column Damper (un tube en U contenant un liquide, TLCD, encore appelé tube anti-roulis), utilisé dans d'autres contextes. Le dispositif que nous proposons est un dispositif actif où les paramètres du TLCD sont ajustés en temps réel, au cours du mouvement induit par les vagues. La mise à jour des paramètres suit une stratégie reposant sur une analyse des interactions entre le TLCD et la plate-forme (appelée ici barge) sur laquelle est installée l'éolienne. Nous avons modélisé le mouvement de la barge seul et son couplage avec le TLCD dans le plan grâce à une approche Lagrangienne. Nous avons étudié les effets des interactions du TLCD avec la barge dans le cas où le coefficient de perte de charge dans le tube était constant. Les limites de cette approche ont été détaillées grâce aux résultats classiques de la littérature sur les oscillateurs mécaniques couplés. Nous nous sommes ensuite concentrés sur une approche active consistant à modifier les caractéristiques du système en temps réel. Nous avons proposé des stratégies de type Linear Quadratic Regulator et de type Model Predictive Control agissant sur le coefficient de perte de charge. Dans un deuxième temps, les simulations nous ont ensuite permis d'écarter la commande MPC dont le rapport performance / complexité n'est pas favorable par rapport à la commande LQR dans ce cas précis.Une étude plus générale du système, en trois dimensions, nous a permis de vérifier que le TLCD classique dans sa version passive ou dans la version active que nous proposions n'est pas du tout robuste à l'incidence de la houle. Nous avons donc imaginé et modélisé des dispositifs inspirés du TLCD mais permettant d'amortir les oscillations de la houle de manière efficace, indépendamment de l'incidence de la houle. Nous avons nommé ces dispositifs TLMCD, pour Tuned Liquid Multiple Columns Damper.Les dispositif que nous proposons sont des systèmes TLMCD actifs. Ils sont conçus d'après les modélisations 3D que nous avons développées et une étude des coûts. Pour ces dispositifs, nous avons aussi détaillé les spécificités de la synthèse des stratégies LQR pour amortir les oscillations de la barge indépendamment de l'incidence de la houle.La performance de ces solutions d'amortissement a finalement été évaluée par simulation pour un large éventail de conditions de houle, couvrant les spécifications d'un “ cahier des charges ” que nous présentons. On observe une réduction des oscillations en roulis de la barge qui peut atteindre un facteur 4 par rapport à l'éolienne flottante sans TLCD. Ces résultats nous montrent que le dispositif TLMCD que nous proposons est un dispositif intéressant pour amortir de manière significative, robuste et économiquement abordable notre système
Thanks to the recent policies of subsidizing renewables energies, constructions of oﬀshore wind farms are booming all over the world. Yet, fixed-bottom wind turbine technology, the only one currently deployed, are too costly for deep waters. This hinders the development of wind power. This is why the scientific community has an interest in floating wind turbines (FWT). The cost of these wind turbines does not depend much on water depth. But since the wind turbine is not fixed into the seabed, the mechanical stress caused by the waves significatively raises.To reduce these detrimental loads, different approaches can be used. The litterature already discarded the control of the wind thrust applied on the rotor to compensate the "fore-aft" oscillations of the tower. We focused on stabilizing floating wind turbine by means of an attached damping system placed inside the float, it is a Tuned Liquid Column Damper (a U-tube containing a liquid, TLCD, also known as anti-roll tank), used in other areas. The damper we propose is an active system where TLCD parameters are continuously modified. Parameters are updated according to a strategy defined thanks to an analysis of the interactions between TLCD and the float (referred to as barge) supporting the wind turbine. We modelled the coupled dynamics of the barge and the TLCD in the vertical plan using a Lagrangian approach. We studied the motions of the damped system for a constant head-loss coefficient in the TLCD. The limits of this approach were detailed thanks to the classic results in double oscillators literature. Then, we focused on an active approach involving a time varying of the head-loss coefficient. We proposed Linear Quadratic Regulator and Model Predictive Control strategies to determine the head-loss coefficient. At a later stage, simulations enabled us to discard the MPC strategy as its complexity/performance ratio is rather bad compared to the LQR strategy in this particular case.A more general study of the system, in three dimensions, showed us that the TLCD is not robust against wave incidence. Therefore, we imagined and modeled new dampers inspired by the TLCD, which can damp the float effectively, regardless of the wave incidence. We named those dampers Tuned Liquid Multiple Column Damper (TLMCD).The dampers we propose are active TLMCD. Their designs are based on their dynamic properties and a cost study. We also detailed the specificities of LQR design to ensure the best possible robustness against wave incidence.The performance of the proposed TLMCD dampers was assessed through numerical simulations for a wide range of sea conditions. We observe that barge roll can be reduced by a factor of four compared to the undamped FWT. These results show us that the TLMCD we propose is interesting to damp significantly, robustly and economically our FWT

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DWIVEDI, ARCHIT. « SEISMIC ANALYSIS OF MULTISTOREYED BUILDINGS WITH AND WITHOUT FLOATING COLUMNS ». Thesis, 2018. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16253.

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In present scenario buildings with floating column is a typical feature in the modern multistory construction in urban India. Such features are highly undesirable in building built in seismically active areas. This study highlights the importance of explicitly recognizing the presence of the floating column in the analysis of building. Alternate measures, involving stiffness balance of the first storey and the storey above, are proposed to reduce the irregularity introduced by the floating columns. The study is carried out on a building with floating columns. The plan layout of the building is shown in the figure. The building considered is a residential building having G+9. Height of each storey is kept same as other prevalent data.

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Livres sur le sujet "FLOATING COLUMNS"

Ken, Wells, dir. Floating off the page : The best stories from the Wall Street journal's "Middle column". New York : Simon & Schuster, 2003.

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Wells, Ken, et Michael Lewis. Floating off the Page : The Best Stories from the Wall Street Journal's "M. Simon & Schuster, Limited, 2008.

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Ken, Wells, dir. Floating off the page : The best stories from the Wall Street journal's "Middle column". New York : Wall Street Journal, 2002.

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(Editor), Ken Wells, et Michael Lewis (Foreword), dir. Floating Off the Page : The Best Stories from The Wall Street Journal's "Middle Column" (Wall Street Journal Book). Simon & Schuster, 2003.

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Michael, Lewis. Floating Off the Page : The Best Stories from the Wall Street Journal's Middle Column. Free Press, 2002.

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Maccracken, Jim. Columbus and Franklin County Ohio Fishing and Floating Guide Book Part 2 : Complete Fishing and Floating Information for Columbus and Franklin County Ohio Part 2 Hellbranch Run Thru Westerville Ponds. Independently Published, 2018.

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Maccracken, Jim. Columbus and Franklin County Ohio Fishing and Floating Guide Book Part 1 : Complete Fishing and Floating Information for Columbus and Franklin County Ohio Part 1 Alum Creek Thru Griggs Reservoir. Independently Published, 2018.

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Chapitres de livres sur le sujet "FLOATING COLUMNS"

Thakur, Arvind, et Amreen Khatun. « Comparative Seismic Analysis of Multi-storied Building with and Without Floating Columns ». Dans Lecture Notes in Civil Engineering, 863–72. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-6557-8_70.

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Jagan, Palani, et Joseph Antony Visuvasam. « Inelastic Seismic Behaviour of RC Buildings with Floating Columns Considering Soil-Structure Interaction ». Dans Proceedings of 17th Symposium on Earthquake Engineering (Vol. 2), 313–24. Singapore : Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1604-7_24.

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M’zoughi, Fares, Payam Aboutalebi, Irfan Ahmad, Izaskun Garrido et Aitor J. Garrido. « Dual Airflow Control Strategy for Floating Offshore Wind Turbine Stabilization Using Oscillating Water Columns ». Dans CONTROLO 2022, 428–38. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-10047-5_38.

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Fayed, Ayman L., Tamer M. Sorour et Hany F. Shehata. « Study of the Behavior of Floating Stone Columns in Soft Clay Formations Using Numerical Modeling ». Dans Soil Testing, Soil Stability and Ground Improvement, 236–51. Cham : Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-61902-6_19.

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Dang, Cong Chi, et Liet Chi Dang. « Influence of Fibre-Reinforced Load Transfer Platform Supported Embankment on Floating Columns Improved Soft Soils ». Dans Lecture Notes in Civil Engineering, 215–27. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2349-6_14.

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Elmeligi, Khaled Hussein, Mamdouh A. Sabry et Waleed El-Sekelly. « Stepped Loading of a Raft Foundation Supported on Deep Soft Clay Improved with Floating Stone Columns ». Dans Advancements in Geotechnical Engineering, 32–43. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-62908-3_3.

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Ali, Mahmoud. « Behavior of Ordinary and Encased Stone Columns End-Bearing and Floating in Soft Clay (Numerical Model) ». Dans Sustainable Civil Infrastructures, 26–38. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01917-4_2.

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Yu, Zhaolong, Xintong Wang, Torgeir Moan, Jørgen Amdahl et Yanyan Sha. « Ultimate and residual strength assessments of intact and collision damaged columns of the Bjørnafjorden floating bridge ». Dans Advances in the Collision and Grounding of Ships and Offshore Structures, 387–93. London : CRC Press, 2023. http://dx.doi.org/10.1201/9781003462170-47.

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Seymour, R. J., et F. N. Spiess. « Large Column-Supported Floating Platforms ». Dans Ocean Space Utilization ’85, 629–36. Tokyo : Springer Japan, 1985. http://dx.doi.org/10.1007/978-4-431-68284-4_70.

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Bargir, Mohasinkhan N., et Ajim G. Mujawar. « Earthquake Analysis of High-Rise Building with Floating Column ». Dans Learning and Analytics in Intelligent Systems, 170–78. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-24314-2_23.

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Actes de conférences sur le sujet "FLOATING COLUMNS"

Ommani, B., H. Lie, V. O. Aksnes, N. Fonseca, P. A. Berthelsen et S.-A. Reinholdtsen. « Extreme Wave Loads on Semi-Submersible Platform Columns, A Case Study ». Dans Structural Load & Fatigue on Floating Structures 2015. RINA, 2015. http://dx.doi.org/10.3940/rina.slf.2015.02.

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Hong, D. C., et S. Y. Hong. « Floating Wave Energy Device With Two Oscillating Water Columns ». Dans ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29103.

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The absorbed power, motion and drift force of a floating wave energy device with two oscillating water column (OWC) chambers are studied taking account of the interaction between two chambers within the scope of the linear wave theory. The oscillating surface-pressure in the OWC chamber is represented by a product of the air-flow velocity and an equivalent linear damping parameter. The two-dimensional potential problem is formulated as a hybrid Green integral equation using the Rankine Green function inside the chamber and the finite-depth free-surface Green function outside respectively. The present numerical method makes it possible to tune the OWC and the floating body motions to the incident waves that is essential to maximize the absorbed power. The absorbed powers are calculated by both the near-field and far-field methods for various values of the linear damping parameter in two chambers. The reflection and transmission coefficients of the body are also presented. The numerical results for one OWC devices where the OWC is placed in a backward and forward bent duct buoys (BBDB and FBDB) are also presented for comparison of the performance. The present floating wave energy devices can also be served as a good floating breakwater having small drift force. The present numerical results show that the existence of reverse time-mean horizontal wave drift force is not contradictory to the principle of wave energy conservation.

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Ma, Q. W., et M. H. Patel. « Coupled Nonlinear Motion of Floating Structures With Water Columns in Open-Bottom Tanks ». Dans ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28548.

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This paper examines the behaviour in ocean waves of floating structures that incorporate open-bottom tanks on their submerged hull geometry. These tanks contain water columns that can flow in or out through their open bottoms, and may also include a volume of trapped air on the top of such water columns. The trapped air acts as a spring with the motion of the floating structures in ocean waves being influenced by interactions between the vessel, the air springs and the water columns underneath them. During operations, the volume of air above the water columns can be trapped or allowed to flow freely to and from the atmosphere.

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Toyoda, Yosuke, Shinichiro Hirabayashi, Rodolfo T. Gonçalves et Hideyuki Suzuki. « Column Interference Effect of Multi-Column Floating Structures on Vortex-Induced Motion Using Numerical Prediction Model ». Dans ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18511.

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Abstract In this study, a numerical prediction model for vortex-induced motions (VIM) of 4-circular-column floater was developed from a database of hydrodynamic forces acquired from the forced oscillation tests. A set of combinations of oscillation frequencies and amplitudes in the transverse direction (1 degree of freedom) were carried out. The numerical results were validated with experimental results of VIM performed in a towing tank. The effect of column interference was discussed by analyzing the hydrodynamic forces on each column separately and also the motion behavior of the floater for spacing ratios between columns, S/D = 2, and 3, where S is the distance between column centers and D is the column diameter.

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de Oliveira, Éverton L., Celso P. Pesce, Bruno Mendes, Renato M. M. Orsino et Guilherme R. Franzini. « A Reduced-Order Mathematical Model for the Current-Induced Motion of a Floating Offshore Wind Turbine ». Dans ASME 2021 3rd International Offshore Wind Technical Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/iowtc2021-3503.

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Abstract Floating offshore platforms motions induced by currents are quite complex phenomena, in general. In particular, VIM, Vortex-Induced Motion, is a type often encountered in platforms with circular columns. Recently, VIM has been observed in towing tank tests with a small-scale model of a Floating Offshore Wind Turbine (FOWT), the OC4 Phase II floater, a 3+1 columns platform. The present paper proposes a reduced-order mathematical model (ROM) to assess VIM of a FOWT. The ROM is derived on the horizontal plane, including yaw motions and nonlinear mooring forces. Current forces are represented through ‘wake variables’, adapting phenomenological models firstly used for VIM of mono-column platforms. The ROM is built upon a set of eleven generalized coordinates, three for the rigid body motion on the horizontal plane and a pair of wake variables for each column, resulting in a system of eleven nonlinear second-order ODEs. The pairs of wake variables obey van der Pol equations, and use hydrodynamic coefficients and parameters obtained from previous experiments with small draught cylinders. Hydro-dynamic interferences among columns or heave plates effects on the flow are not considered, for simplicity. The validity of the proposed model is assessed having the mentioned small-scale experimental campaign as a case study. The simulations are carried out at three different current incidence angles, 0, 90 and 180 degrees, spanning a large range of reduced velocities. The simulations reproduce well the oscillations observed in the experimental tests. A good agreement in transverse oscillations is found, including lock-in regions. The simulations also depict a possibly important phenomenon: a resonant yaw motion emerging at high reduced velocities.

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Murai, Motohiko, Yoshiyuki Inoue et Tomoyuki Kibe. « Hydroelastic Responses of a Very Large Floating Structure Supported by Footing-Columns in Waves ». Dans ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37030.

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A Very Large Floating Structure (VLFS) is expected as a new utilization of ocean space and coastal region. In Japan, there are many feasibility studies about the hydroelastic responses induced by wave forces for the reason of the relative small rigidity of VLFS. The VLFS supported by columns generally shows smaller elastic responses than those of the pontoon type VLFS. In this paper we discuss the hydroelastic responses of the VLFS supported by large number of columns which have one or two wave-free frequencies for heave. We investigate the hydroelastic behaviors of the VLFS in regular and irregular waves. Furthermore we compare the hydroelastic responses of following three types VLFS in irregular waves. First one is supported by cylindrical columns without wave-free frequency, second one is supported by columns with one wave-free frequency and third one is supported by columns with two wave-free frequencies.

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Yang, Zhiyong, Xiaoqiang Bian et Yu Shi. « PyraWind™ : An Innovative Floating Offshore Wind Turbine (FOWT) Global Performance Analysis ». Dans ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/omae2021-62640.

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Abstract In the near future, the offshore wind industry will experience a significant increase of turbine size and of floating wind development activities. A floating offshore wind turbine foundation offers many advantages, such as flexibility in site selection, access to better offshore wind resources, and quayside integration to avoid a costly heavy lift vessel offshore campaign. PyraWind™ is a patented three canted column semisubmersible floating foundation for ultra large offshore wind turbines. It is designed to accommodate a wind turbine, 14 MW or larger, in the center of the interconnected columns of the hull with minimal modifications to the tower, nacelle and turbine. The pyramid-shaped hull provides a stable, solid foundation for the large wind turbine under development. This paper summarizes the feasibility study conducted for the PyraWind™ concept. The design basis for wind turbine floating foundations is described and the regulatory requirements are discussed. Also included are the hydrodynamic analysis of the hull and ongoing work consisting of coupling hull hydrodynamics with wind-turbine aerodynamic loads. The fully coupled system was analyzed using OpenFAST, an aerodynamic software package for wind turbine analysis with the ability to be coupled with the hydrodynamic model. Due to the canted columns, a nonlinear analysis was performed using the coupled numerical hydrodynamic model of the platform with mooring system in extreme sea states.

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Nanjo, Takanori, Toshikazu Miyashita, Shunji Kataoka et Takuya Sato. « Study on Intermediate Support of Tall Columns for FPSO Topside Structures ». Dans ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63177.

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FPSO (Floating Production, Storage and Offloading) has become used increasingly for off-shore gas fields. Most tall pressure vessels such as columns installed in the FPSO are surrounded by topside structures. In general, columns in on-shore plants are supported only by bottom skirts; on the other hand, some of the tall columns on FPSO hulls require intermediate supports in addition to bottom skirts because of large accelerations they are subject to due to ship motion induced by wave loading. In this paper, the effects of the support were investigated considering acceleration distributions and structure deformation (drift), then the ideal elevation of the support was determined to minimize bending moment throughout the columns under the combined conditions. A dimensionless controlling parameter related to the acceleration, structure drift, and column properties was proposed and graphs (called N-Charts) were proposed to understand effects in reducing the maximum bending moment with respect to the elevation of the guide.

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Jagarapu, Durga Chaitanya Kumar, Srikanth Kristam, V. L. D. Prasada Reddy, J. Vijaya Chandra et A. L. S. K. S. V. D. Gupta. « Analysis and design of building with floating columns for different slab systems ». Dans ADVANCES IN SUSTAINABLE CONSTRUCTION MATERIALS. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0146408.

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Wu, Chih-Hua, Teck-Bin Arthur Lim, Chang-Wei Kang et Shengwei Ma. « Investigation of Effect of Twisted Surface on Suppression of Vortex-Induced Motion of a Square Column ». Dans ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77107.

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Suppression of vortex-induced motion (VIM) of multi-columns semisubmersibles is an important factor for the safety design and operating environment of floating platforms. Vortex generation around square columns is a key issue to cause VIM, and thus, an essential point for suppressing VIM is to desynchronize vortex shedding frequency and natural frequency of the system. In our work, we investigate the effect of a square column with the twisted surface on the suppression of VIM. The numerical tool we used in this work is an open source package, OpenFOAM, to solve transient flow pattern around a vibrating square column. The numerical validation of the present study is done by benchmarking with the reported experimental work at moderate Reynolds numbers (Re). In real sea state, the flow around floating structure is turbulent and is in high Re region. We implemented k-ω SST DES turbulence model in the present numerical model to solve complex turbulent flow around the square column with the twisted surface at high Re. By comparison with VIM of a square column, the VIM reduction of a twisted column is significant, which is up to 86% of VIM reduction. The vortex structure, flow separation points and vortex shedding frequency are varied in the spanwise direction of the twisted column, which causes the effect of vortex desynchronization on the VIM. The detailed flow pattern, 3D vortex structure (Q criterion) around the twisted column is demonstrated as well. A remarkable conclusion is made based on the present numerical findings.

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Rapports d'organisations sur le sujet "FLOATING COLUMNS"

Brefort, Dorian, et Diana L. Bull. Mooring Design for the Floating Oscillating Water Column Reference Model. Office of Scientific and Technical Information (OSTI), septembre 2014. http://dx.doi.org/10.2172/1323372.

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Beck, Aaron. NAPTRAM - Plastiktransportmechanismen, Senken und Interaktionen mit Biota im Nordatlantik / NAPTRAM - North Atlantic plastic transport mechanisms, sinks, and interactions with biota, Cruise No. SO279, Emden (Germany) – Emden (Germany), 04.12.2020 – 05.01.2021. Gutachterpanel Forschungsschiffe Bonn, 2021. http://dx.doi.org/10.3289/cr_so279.

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The coastal and open oceans represent a major, but yet unconstrained, sink for plastics. It is likely that plastic-biota interactions are a key driver for the fragmentation, aggregation, and vertical transport of plastic litter from surface waters to sedimentary sinks. Cruise SO279 conducted sampling to address core questions of microplastic distribution in the open ocean water column, biota, and sediments. Seven stations were sampled between the outer Bay of Biscay and the primary working area south of the Azores. Additional samples were collected from surface waters along the cruise track to link European coastal and shelf waters with the open ocean gyre. Microplastic samples coupled with geochemical tracer analyses will build a mechanistic understanding of MP transport and its biological impact reaching from coastal seas to the central gyre water column and sinks at the seabed. Furthermore, floating plastics were sampled for microbial community and genetic analyses to investigate potential enzymatic degradation pathways. Cruise SO279 served as the third cruise of a number of connected research cruises to build an understanding of the transport pathways of plastic and microplastic debris in the North Atlantic from the input through rivers and air across coastal seas into the accumulation spots in the North Atlantic gyre and the vertical export to its sink at the seabed. The cruise was an international effort as part of the JPI Oceans project HOTMIC (“HOrizontal and vertical oceanic distribution, Transport, and impact of MICroplastics”) and the BMBF funded project PLASTISEA (‘Harvesting the marine Plastisphere for novel cleaning concepts’), and formed a joint effort of HOTMIC and PLASTISEA researchers from a range of countries and institutes.

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Beck, Aaron. RiverOceanPlastic : Land-ocean transfer of plastic debris in the North Atlantic, Cruise No. AL534/2, 05 March – 26 March 2020, Malaga (Spain) – Kiel (Germany). GEOMAR Helmholtz Centre for Ocean Research Kiel, 2020. http://dx.doi.org/10.3289/cr_al534-2.

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Cruise AL534/2 is part of a multi-disciplinary research initiative as part of the JPI Oceans project HOTMIC and sought to investigate the origin, transport and fate of plastic debris from estuaries to the oceanic garbage patches. The main focus of the cruise was on the horizontal transfer of plastic debris from major European rivers into shelf regions and on the processes that mediate this transport. Stations were originally chosen to target the outflows of major European rivers along the western Europe coast between Malaga (Spain) and Kiel (Germany), although some modifications were made in response to inclement weather. In total, 16 stations were sampled along the cruise track. The sampling scheme was similar for most stations, and included: 1) a CTD cast to collect water column salinity and temperature profiles, and discrete samples between surface and seafloor, 2) sediment sampling with Van Veen grab and mini-multi corer (mini-MUC), 3) suspended particle and plankton sampling using a towed Bongo net and vertical WP3 net, and 4) surface neusten sampling using a catamaran trawl. At a subset of stations with deep water, suspended particles were collected using in situ pumps deployed on a cable. During transit between stations, surface water samples were collected from the ship’s underway seawater supply, and during calm weather, floating litter was counted by visual survey teams. The samples and data collected on cruise AL534/2 will be used to determine the: (1) abundance of plastic debris in surface waters, as well as the composition of polymer types, originating in major European estuaries and transported through coastal waters, (2) abundance and composition of microplastics (MP) in the water column at different depths from the sea surface to the seafloor including the sediment, (3) abundance and composition of plastic debris in pelagic and benthic organisms (invertebrates), (4) abundance and identity of biofoulers (bacteria, protozoans and metazoans) on the surface of plastic debris from different water depths, (5) identification of chemical compounds (“additives”) in the plastic debris and in water samples.

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