Academic literature on the topic 'Offshore pile performance'
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Journal articles on the topic "Offshore pile performance"
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Li, Zheming, Malcolm D. Bolton, and Stuart K. Haigh. "Cyclic axial behaviour of piles and pile groups in sand." Canadian Geotechnical Journal 49, no. 9 (September 2012): 1074–87. http://dx.doi.org/10.1139/t2012-070.
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Piled foundations are often subjected to cyclic axial loads. This is particularly true for the piles of offshore structures, which are subjected to rocking motions caused by wind or wave actions, and for those of transport structures, which are subjected to traffic loads. As a result of these cyclic loads, excessive differential or absolute settlements may be induced during the piles’ service life. In the research presented here, centrifuge modelling of single piles and pile groups was conducted to investigate the influence of cyclic axial loads on the performance of piled foundations. The influence of installation method was investigated and it was found that the cyclic response of a pile whose jacked installation was modelled correctly is much stiffer than that of a bored pile. During displacement-controlled axial load cycling, the pile head stiffness reduces with an increasing number of cycles, but at a decreasing rate; during force-controlled axial load cycling, more permanent settlement is accumulated for a bored pile than for a jacked pile. The performance of individual piles in a pile group subjected to cyclic axial loads is similar to that of a single pile, without any evident group effect. Finally, a numerical analysis of axially loaded piles was validated by centrifuge test results. Cyclic stiffness of soil at the base of pre-jacked piles increases dramatically, while at base of jacked piles it remains almost constant.
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Zhang, Zhaohui, Peng Guan, Jinlong Xu, Benzhang Wang, Hui Li, and Yongkang Dong. "Horizontal Loading Performance of Offshore Wind Turbine Pile Foundation Based on DPP-BOTDA." Applied Sciences 10, no. 2 (January 9, 2020): 492. http://dx.doi.org/10.3390/app10020492.
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Offshore wind power is becoming attractive in the wind-power field. With the rapid development of wind-power technology, high-power wind turbines have been implemented in practice. However, the increase in the length of the wind turbine blade causes the pile foundation to withstand a prone overturning moment. For overcoming the problems of traditional sensing technology and meeting the monitoring requirements of pile foundations, a 20 cm spatial resolution differential pulse pair Brillouin optical time-domain analysis (DPP-BOTDA) technique is used to measure a 69 m long offshore wind turbine pile under horizontal loading. From the distributed strain data collected in the test, the maximum stress location of the long pile under the horizontal load can be obtained. By analyzing the load and maximum strain (F-εmax) curve, the horizontal bearing capacity of the pile foundation can exceed 900 kN, which is the maximum horizontal load of the design. The distributed displacement calculation method based on distributed strain data is proposed, according to the force characteristics of steel pipe piles. By comparing the calculated displacement data with the measured data by the dial indicators, the mean absolute percentage error (MAPE) value is only 0.03548. Results show that the 20 cm spatial resolution DPP-BOTDA technology is very suitable for the bearing capacity test of offshore wind turbine steel pipe pile foundations.
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Yang, Jing Ping. "Numerical Analysis on Performance of Frame-Shear Structure with High Pile under Complex Load." Advanced Materials Research 1044-1045 (October 2014): 650–53. http://dx.doi.org/10.4028/www.scientific.net/amr.1044-1045.650.
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In order to acquire mechanical performance of High cap supporting frame-shear structure, in view of the sea high cap supporting frame-shear theory analysis and numerical simulation of structure is less, this paper performs numerical simulation analysis for pile caps-soil-the upper structure using the finite element software ANSYS. Expression equation of wave force is given, and three-dimensional finite element model is established. By Analysis the deformation and stress of pile foundation and pile caps under different load combinations are obtained, and the deformation, bending moment of pile top, axial force are checked, finally the feasibility of the system is verified, and these can provide a reliable basis and reference for reasonable design of offshore structures. High cap supporting frame-shear structure for its strong adaptability is widely used in offshore construction system.
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Basack, Sudip. "Analysis and Design of Offshore Pile Foundation." Advanced Materials Research 891-892 (March 2014): 17–23. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.17.
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The ocean environment necessitates the pile foundation supporting the offshore structures to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition induces progressive degradation in the pile-soil interactive performance introducing significant reduction in bearing capacity with increased settlement and displacements. The Author has carried out extensive experimental (laboratory model tests) and theoretical investigations (boundary element analysis) to study the salient features of this degradation and developed a design methodology for offshore pile foundation. The works conducted and the major conclusions drawn are highlighted in this paper.
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Xu, Xiangtao, James A. Schneider, and Barry M. Lehane. "Cone penetration test (CPT) methods for end-bearing assessment of open- and closed-ended driven piles in siliceous sand." Canadian Geotechnical Journal 45, no. 8 (August 2008): 1130–41. http://dx.doi.org/10.1139/t08-035.
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The cone penetration test (CPT) has been used as a means of assessing the end bearing of driven piles in sand for many decades. This paper examines the predictive performance of four new such CPT-based methods recently included in the commentary of the 22nd edition of the American Petroleum Institute’s recommended practice for fixed offshore structures. It is demonstrated that the formulations given by one of these methods, referred to as UWA-05, provides better predictions than the three other CPT methods when tested against (i) an existing database of base-capacity measurements, (ii) results from a new series of load tests on small-diameter piles, and (iii) base capacities measured in two recently conducted load tests on 1.5 m diameter pipe piles. It is shown that the UWA-05 has better predictive performance (and hence reliability) as it accounts explicitly for the effects of partial plugging during pipe–pile installation and for variations in CPT resistance in the vicinity of the pile tip.
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Barbosa, V. D., and N. S. Galgoul. "Designing Piled Foundations with a Full 3D Model." Open Construction and Building Technology Journal 12, no. 1 (March 30, 2018): 65–78. http://dx.doi.org/10.2174/1874836801812010065.
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Background:The analysis of piled foundations, where horizontal environmental loads play a very important role, has taken foundation design a step further in the 1970s and 80s. Nonlinear analyses considering P-y, T-z and Q-z curves became the state-of-the-art which also included group effect calculations thanks to an approximation proposed by [1] on the [2] equations. For some reason, however, foundation design continued to be refined using finite element calculations, but the corresponding developments never made their way into the main offshore platform design codes such as [3,4].Objective:Considering the enormous advantage that this brings for topics such as group effect and negative friction, it is obvious that opening the offshore market to this enhancement is totally desirable. This is exactly what this paper is trying to achieve.Method:In order to increase the accuracy of the prediction of piled foundations lateral displacements when group effect is considerable, a complete 3D model will be proposed using the finite element method and compared to the codes’ model and also experimental data.Results:The model in DIANA showed good performance in comparison to the codes’ model and experimental data for the single pile. When the pile group model, when the codes’ have known deficiencies, was tested, both efforts on each pile and mean displacement of the pile group fit the experimental data. However, the behavior of each pile of the group, if separately analyzed, didn’t fit many experimental data, which was attributed to the soil model utilized.Conclusion:This improved modeling procedure has been proven to improve the lateral displacement prediction of a piled foundation when group effect is considerable, when compared to codes [3,4] proposed models. However, the study of more accurate soil models could help on achieving more realistic results.
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Wang, Zhuo, Zhuang Li, Tao Wang, and Bo Zhang. "Study on Clamping Mechanism of Internal and External Variable Diameter Lifting Tool for Offshore Foundation Pile." Machines 9, no. 1 (January 17, 2021): 19. http://dx.doi.org/10.3390/machines9010019.
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Large marine foundation piles are an important part of offshore structural pile foundations, and their lifting operations have always been a major problem in the construction and construction of marine structures. Based on IHC’s bilateral marine foundation pile spreader, this paper proposes a structural scheme of “internal and external clamping type variable diameter marine foundation pile spreader”. It solves the problem of poor adaptability of spreaders to foundation piles of the same specification and different pipe diameters. At the same time, this article has conducted in-depth research on the two clamping methods of friction clamping and wedge tooth embedded clamping. Through experiments, it is found that under the same lateral load, the load capacity of the wedge teeth tightening is three times that of the friction clamping. Aiming at the embedding and clamping method of the wedge teeth of the spreader, first of all, the influence of the tooth profile angle of the wedge teeth on their embedding performance was studied by the plastic mechanics slip line field theory and Abaqus simulation analysis. Subsequently, the elastic mechanics theory and Abaqus simulation analysis were used to study the stress characteristics of the wedge teeth during the lifting process, and the internal stress distribution was obtained. The article aims to provide a reference for the design of spreaders in actual projects.
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Basack, Sudip, and Abhik Kumar Banerjee. "Offshore Pile Foundation Subjected to Lateral Cyclic Load in Layered Soil." Advanced Materials Research 891-892 (March 2014): 24–29. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.24.
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The pile foundations supporting offshore structures are required to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition produces progressive degradation in the pile-soil interactive performance which is likely to introduce significant reduction in bearing capacity with increased settlement and displacements. This paper is based on a numerical model developed by the Authors to study the response of pile foundation under lateral cyclic load in layered soil. The model is validated with a field test data and thereafter, parametric studies have been carried out. A brief description of the works conducted and the major conclusions drawn are highlighted in this paper.
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Tirandazian, Mehran, and Gholamreza Nouri. "Numerical modeling of the seismic performance of monopile supported wind turbines in sandy soils susceptible to liquefaction." International Journal of Engineering & Technology 7, no. 2.13 (April 15, 2018): 263. http://dx.doi.org/10.14419/ijet.v7i2.13.12676.
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Since 1980, as wind farms have moved from coastal to offshore areas, the wind energy industry has been completely transformed which in turn has led to the increase in the construction of wind turbines. On the other hand, harsher offshore environmental conditions have led to larger lateral loads and anchorages applied to the wind turbines and specifically to their piles than other coastal and offshore structures. Thus, more solid piles are required to ensure proper rigidity and bearing capacity. Liquefaction is one of the most important seismic hazards through which various damages caused to different parts of wind turbines. In order to develop coastal and offshore structures in Iran, a study of liquefaction is of great importance due in part to the high risk of seismicity. In this study, the effect of liquefaction on seismic response of offshore wind turbines is examined taking advantage of a finite element model. To this end, all analyzes have been carried out in both occurrence and non-occurrence of the liquefaction, so that by comparing these two modes, the mechanisms affecting the seismic behavior of wind turbines are understood. As depth increases, the possibility of liquefaction is reduced due to higher pressure. Liquefaction is considered to a depth of 20 m and structural behavior is evaluated based on the level of seismic hazard, the thickness of the susceptible layers, soil compaction, the non-fluidizing top layer, the gradient of the earth, the thickness of the monopole, the dimensions of the wind turbine and different soil layering conditions. According to the mentioned factors, a comprehensive and parametric study of the behavior of wind turbines in seismic zones, and in different loading conditions, pile diameters and soil layering is carried out in soils prone to liquefaction. Since analyzes are performed in both occurrence and non-occurrence of the liquefaction, the number of analyzes and computational cost in this research becomes enormous. Therefore, there is a need for a highly effective software and a practical modeling method that will allow for this comprehensive study. Open Sees software and beam on nonlinear Winkler foundation approach are used to model the soil-pile-structure interaction. The minor differences observed in the laboratory values compared to the numerically calculated ones may refer to the fact that the chamber is not modeled. In the bottom layer, as the depth decreases, the elastic response spectra record larger values which are due to the resonance in the structure.
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Jalbi, Saleh, Joseph Hilton, and Luke Jacques. "Assessment of Practical Methods to Predict Accumulated Rotations of Monopile-Supported Offshore Wind Turbines in Cohesionless Ground Profiles." Energies 13, no. 15 (July 31, 2020): 3915. http://dx.doi.org/10.3390/en13153915.
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Monopiles supporting offshore wind turbines can experience permanent non-recoverable rotations (or displacements) during their lifetime due to the cyclic nature of hydrodynamic and aerodynamic loading exerted on them. Recent studies in the literature have demonstrated that conventional cyclic p–y curves recommended in different codes of practice (API-RP-2GEO and DNVGL-RP-C212) may not capture the effects of long-term cyclic loads as they are independent of the loading profile and the number of applied cycles. Several published methodologies based on laboratory scaled model tests (on sands) exist to determine the effect of cyclic lateral loads on the long-term behaviour of piles. The tests vary in terms of the pile behaviour (rigid or flexible pile), number of applied loading cycles, and the load profile (one-way or two-way loading). The best-fit curves provided by these tests offer practical and cost-efficient methods to quantify the accumulated rotations when compared to Finite Element Method. It is therefore desirable that such methods are further developed to take into account different soil types and the complex nature of the loading. The objective of this paper is to compare the performance of the available formulations under the actions of a typical 35-h (hour) storm as per the Bundesamt für Seeschifffahrt und Hydrographie (BSH) recommendations. Using classical rain flow counting, the loading time-history is discretized into load packets where each packet has a loading profile and number of cycles, which then enables the computation of an equivalent number of cycles of the largest load packet. The results show that the loading profile plays a detrimental role in the result of the accumulated rotation. Furthermore, flexibility of the pile also has an important effect on the response of the pile where predictions obtained from formulations based on flexible piles resulted in a much lower accumulated rotation than tests based on rigid piles. Finally, the findings of this paper are expected to contribute in the design and interpretation of future experimental frameworks for Offshore Wind Turbine (OWT) monopiles in sands, which will include a more realistic loading profile, number of cycles, and relative soil to pile stiffness.
Dissertations / Theses on the topic "Offshore pile performance"
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Lambson, M. D. "The behaviour of axially loaded piles in clay." Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233363.
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Xu, Xiangtao. "Investigation of the end bearing performance of displacement piles in sand." University of Western Australia. School of Civil and Resource Engineering, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0086.
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[Truncated abstract] The axial performance of piles in sand remains an area of great uncertainty in geotechnical engineering. Over the years, database studies have shown that the existing method for offshore piles (e.g. API 2000) is unreliable. There is therefore a clear need for an improved predictive method, which incorporates the state-ofthe- art understanding of the underlying controlling mechanisms. This Thesis is dedicated to address the factors influencing the end bearing performance of displacement piles in siliceous sand with a view to proposing and justifying an improved design formulation. Firstly, a database of displacement pile load tests in sand with CPT data was compiled in collaboration with James Schneider (Schneider 2007). It features the widest database with also the latest available pile load test data (e.g. Euripides, Ras Tanajib, Drammen etc) in electronic form. Evaluation of the three new CPTbased methods (Fugro-05, ICP-05 & NGI-05) against this database has revealed a broadly similar predictive performance despite their end bearing formulations being remarkably different. This anomaly promoted the author to extend the database to include additional tests with base capacity measurements to form new base capacity databases for driven and jacked piles, which resulted in the UWA- 05 method for end bearing of displacement piles in sand. This method accounts for the pile effective area ratio, differentiates between driven and jacked piles, and employs a rational qc averaging technique. ... Field tests were performed in Shenton Park, Perth to supplement the database study and, in particular, to examine the effect of the incremental filling ratio (IFR). 10 open-ended and 2 closed-ended piles were tested in compression followed by tension. The test results provide strong support for the UWA-05 method for base capacity evaluation employing the CPT qc values and the effective area ratio. A series of jacked pile tests was carried out on the UWA beam centrifuge, to further explore the factors affecting pile base response. In total, four uniform and four layered centrifuge samples were prepared and tested at various stress levels and relative densities using three separate pile diameters. The resistance ratio (qb0.1/qc,avg) is found to be independent of the absolute pile diameter, effective stress and soil relative density. The tests in layered soil enabled quantification of the reduction in penetration resistance when a pile/cone approaches a weak layer and revealed the significant influence on base stiffness of underlying soft clay layers. The stiffness decay curves (G/GIN vs. w/D, where GIN is initial operational shear stiffness) measured in static load tests were found to vary with ratios of GIN/qc, while there was a unique relationship between G/GIN and qb/qc. A detailed parametric study was carried out (using the FE code PLAXIS) by idealising pile penetration using a spherical cavity expansion analogue in layered soil. The numerical predictions compare well with the centrifuge results and their generalization enabled guidelines to be established for end bearing in layered soil.
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Chen, Jiun-Yih. "Analysis of performance and reliability of offshore pile foundation systems based on hurricane loading." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-3342.
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Jacket platforms are fixed base offshore structures used to produce oil and gas in relatively shallow waters worldwide. Their pile foundation systems seemed to perform better than what they were designed for during severe hurricanes. This observation has led to a common belief in the offshore oil and gas industry that foundation design is overly conservative.
The objective of this research is to provide information to help improve the state of practice in designing and assessing jacket pile foundations to achieve a consistent level of performance and reliability. A platform database consisting of 31 structures was compiled and 13 foundation systems were analyzed using a simplified foundation collapse model, supplemented by a 3-D structural model.
The predicted performance for most of the 13 platform foundations is consistent with their observed performance. These cases do not preclude potential conservatism in foundation design because only a small number of platform foundations were analyzed and only one of them actually failed. The potential failure mechanism of a foundation system is an important consideration for its performance in the post-hurricane assessment. Structural factors can be more important than geotechnical factors on foundation system capacity. Prominent structural factors include the presence of well conductors and jacket leg stubs, yield stress of piles and conductors, axial flexibility of piles, rigidity and strength of jackets, and robustness of foundation systems. These factors affect foundation system capacity in a synergistic manner. Sand layers play an important role in the performance of three platform foundations exhibiting the largest discrepancy between predicted and observed performance. Site-specific soil borings are not available in these cases. Higher spatial variability in pile capacity can be expected in alluvial or fluviatile geology with interbedded sands and clays.
The uncertainties in base shear and overturning moment in the load are approximately the same and they are slightly higher than the uncertainty in the overturning capacity of a 3-pile foundation system. The uncertainty in the overturning capacity of this foundation system is higher than the uncertainty in shear capacity. These uncertainties affect the reliability of this foundation system.text
Book chapters on the topic "Offshore pile performance"
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Thakare, S. W., Aparna H. Chavan, and A. I. Dhatrak. "Performance of Suction Pile Anchor for Floating Offshore Structures." In Lecture Notes in Civil Engineering, 271–84. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6090-3_18.
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Hu, Yayun, Yiliang Zhang, and Xiaoliang Jia. "The Stress Corrosion Performance Research of Three Kinds of Commonly used Pipe Materials." In HSLA Steels 2015, Microalloying 2015 & Offshore Engineering Steels 2015, 807–13. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119223399.ch100.
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Hu, Yayun, Yiliang Zhang, and Xiaoliang Jia. "The Stress Corrosion Performance Research of Three Kinds of Commonly Used Pipe Materials." In HSLA Steels 2015, Microalloying 2015 & Offshore Engineering Steels 2015, 807–13. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-48767-0_100.
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Whittle, A. J. "Assessment of an Effective Stress Analysis for Predicting the Performance of Driven Piles in Clays." In Advances in Underwater Technology, Ocean Science and Offshore Engineering, 607–43. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-017-2473-9_29.
Full textConference papers on the topic "Offshore pile performance"
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Lowes, J. M., Robert Holmes, and J. W. Peel. "Performance of a Swage Pile/Sleeve Connection When Subjected to Cycle Loading." In Offshore Technology Conference. Offshore Technology Conference, 1992. http://dx.doi.org/10.4043/6950-ms.
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Doyle, Earl H. "Pile Installation Performance for Four TLP's in the Gulf of Mexico." In Offshore Technology Conference. Offshore Technology Conference, 1999. http://dx.doi.org/10.4043/10826-ms.
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Parker, Eric J., Fabrizio Ardoino, and Sabrina Bughi. "Performance Based Seismic Design of Suction Pile Foundations." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11465.
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Deepwater subsea developments require installation of relatively large, heavy structures in poor soil conditions. In many cases, the foundations of choice are large diameter suction piles. The industry has excellent experience in design of these foundations for operational conditions, but offshore codes provide little guidance regarding performance during earthquakes. This paper presents an example of a recent project where suction piles were used to support large manifold structures in a seismically active region. Preliminary verifications using a conventional pseudostatic approach showed that the planned foundations would have been unsatisfactory for seismic loadings. More detailed performance based design was employed to avoid over-dimensioning the piles. Dynamic finite element analysis was used to evaluate structure displacements during and after the design earthquake. Advanced soil models were required to capture the nonlinear behavior of the soft soils at the site. The manifold displacements were compared to operational requirements to assess foundation acceptability. The approach provided considerable savings. This paper outlines the main aspects of the two approaches, and shows the advantages of performance based design for these structures. Our conclusion is that careful analysis is required for the soil conditions typically found at deepwater sites; standard simplified approaches may not suffice.
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Castillo Garcia, Pablo, and Stylianos Panayides. "Effect of Fins on Combined Loaded Suction Caisson in Deepwater Clay Soils. A Numerical Analysis." In Offshore Technology Conference. OTC, 2021. http://dx.doi.org/10.4043/30973-ms.
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Abstract Suction piles are a form of foundation widely adopted in the offshore energy industry. Efforts to enhance the combined Vertical-Horizontal (V-H) performance of piles with the addition of fins, attracted interest from the engineering community in the beginning of the 21st century. Design of this enhancement was surfaced whilst examining foundation solutions for renewable energy projects. Studies to date have primarly considered relatively shallow waters comprising sandy soils, with the behaviour of fin-enhanced piles in very soft to soft clay soils, receiving less attention. The present study emphasis is on typical deep-water deposits of soft clay and attempts to evaluate the impact of varying fin length, shape, orientation and location, on the combined capacity of suction piles by means of three-dimensional finite element analyses. The paper investigates two types of load configuration; in the first instance loading at the pile head and secondly with the load attachment point located at approximately two thirds of the pile embedded length. These two configurations cover different foundation solutions, such as support for subsea infrastructure and anchoring for floating facilities, respectively. Optimum fin-enhanced suction pile configurations are presented for each application, with the results from this study indicating an increase of the load-carrying capacity in V-H space, whilst reducing the overall suction pile size. The efficiency of various configurations is presented with composite plots of increase in holding capacity, plotted against the increase in steel surface area. Preliminary recommendations on fin length, location, shape and orientation for typical suction pile applications are presented with intent to demonstrate the potential for cost savings and reduction in both operational and schedule risk.
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Mostafa, Yasser E., and M. Hesham El Naggar. "Effect of Dynamic Behaviour of Piles on Offshore Towers Response." In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28582.
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Pile foundations supporting offshore platforms and marine structures are required to resist dynamic lateral loading due to wind and wave forces. The response of a jacket offshore tower is affected by the foundation flexibility and the nonlinear behaviour of the supporting piles. In the present study, the soil resistance to the pile movement is modeled using dynamic p-y curves and t-z curves to account for soil nonlinearity and energy dissipation through radiation damping. The model also allows separation at the pile soil interface. The wave forces on the tower members and the tower response are calculated in the time domain using a finite element package (ASAS). The tower response is calculated with emphasis placed on the effects of dynamic pile-soil interaction on the tower performance and the forces acting on the piles for a range of wave conditions.
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Rausche, Frank, Matt Nagy, Scott Webster, and Liqun Liang. "CAPWAP and Refined Wave Equation Analyses for Driveability Predictions and Capacity Assessment of Offshore Pile Installations." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-80163.
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Open ended pipe piles have to be driven in the offshore environment primarily as platform support piles or as conductor pipes. In either case, deep penetrations have to be achieved. In preparation of these potentially difficult installations, equipment selection and stress control is done by a predictive wave equation analysis. During pile driving, dynamic monitoring combined with CAPWAP signal matching analysis is a preferred method for bearing capacity assessment. After the fact, if dynamic measurements were not provided during pile driving, a wave equation analysis can again help perform a post-installation analysis for bearing capacity assessment, assuming a variety of parameters. Wave equation analyses require a variety of input parameters describing hammer and driving system performance and the pseudo-static and dynamic behavior of the soil. Measurements taken during the installation yield immediate results about hammer and pile performance. Soil resistance parameters can be extracted by careful signal matching analysis. Unfortunately, the measurement and associated analysis results cannot be used without further modification in the wave equation analysis, because the wave equation approach requires simplifications in hammer, driving system and soil models. Thus, a final step is the so-call Refined Wave Equation Analysis which combines all results obtained and produces a best possible match between measurements and analyses. This paper describes the process of the three analysis phases utilizing typical offshore pile installation records. The paper also gives guide lines for this analysis process as well as a summary of limitations. An important part of the paper includes recommendations for and discussion of the modeling of the soil resistance near the open ended pipe bottom. Finally, the paper discusses how the results should be used for greatest benefit of the deep foundation industry.
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Valle, C., P. Barrera, and V. Taboada. "Effect of Strain Rate, Sampling Technique and Aging on the Soil Properties Used in the Reassessment of Pile Foundations Performance in the Bay of Campeche." In Offshore Technology Conference. Offshore Technology Conference, 1998. http://dx.doi.org/10.4043/8740-ms.
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Bughi, Sabrina, and Eric Parker. "Suction Pile Foundations: Experience in the Mediterranean Offshore and Installation Feedback." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49871.
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Suction piles are widely used in deepwater engineering both for anchoring and as foundation systems. In the first case the piles serve as anchor points for mooring systems in alternative to more standard drag anchors or piles. More recently, however, they have been used as structure foundations. In this role suction piles are a competitive alternative to the more traditional solutions of driven piles or mudmats, for platform jackets, subsea systems and subsea equipment protection structures. This solution provides cost savings in fabrication and required installation equipment. Furthermore, the foundations are relatively easy and rapid to install and can be positioned with high precision by controlled and simple marine operations, and they can be removed for reuse. This paper describes the use of steel suction piles for deepwater subsea Manifolds, Tie-in Spool Bases and Subsea Control Distribution Assemblies, in the West Delta Deep Marine (WDDM) and Rosetta concessions offshore Egypt. Most of the structures were supported by a single suction pile foundation; pile diameters ranged from 4 m to 8 m and penetrations from 8 m to 12 m. One of the larger units was supported by a “quad” foundation frame with four suction piles. Soils in the area are very soft, normally consolidated clays typical of deepwater conditions. Design is complicated by seismicity of the area, which required the foundations to resist significant horizontal dynamic loads in addition to the normal vertical operating loads. The solution adopted utilized an internal top plate in contact with the soil allowing full development of base bearing capacity. As the pile skin friction in these soils is very low, the increased end bearing leads to significant savings on foundation weight and cost. The paper discusses the main aspects of foundation design, covering the installation process with expected self weight penetration and the required suction to achieve the target design penetration, the retrieval operation for repositioning in case the final inclination is out of tolerance, the assessment of the bearing capacity and the stability under the combined vertical, horizontal and overturning loads during operation and earthquake conditions. Seismic design was based on a nonlinear dynamic analysis. In some cases the seismic loads were comparable to the ultimate foundation capacity and the final acceptance criteria utilized a Performance Based Design philosophy. In this approach the foundation is considered acceptable if the deformation experienced by the structure, during and after the seismic event, does not jeopardize structural integrity.
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Li, Shuzhao, Zhongchang Wang, Xu Jia, and Linlin He. "Response Study of Jacket Piles Induced by Spudcan Penetration." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78337.
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Mobile jack-up rigs are frequently cantilevered over production jacket platforms to drill new wells or rework existing well for the offshore oil and gas at shallow and middle water depths. The proximity of the rig to the existing fixed platform will affect the performance of pile foundations of the platform and may cause some distress to the adjacent pile foundation by spudcan penetration. With the increasing accidents with respect to the spudcan penetration and spudcanpile interaction caused severe economic losses in offshore engineering of China, solving these problems is an urgent and significance assignment at present. Since the spudcan-pile interaction is a typical offshore geotechnical large strain large deformation problem, a numerical approach based on the large strain technique is a valid solution tool for evaluating spudcanpile interaction. The paper addresses additional responses of the adjacent pile induced by spudcan penetration in single clay profile and clay overlying sand profile using two different large strain large deformation numerical approaches. One is called two-stage approach. Firstly, ALE (Arbitrary Lagrangian Eulerian) approach is used to the displacement field of soil is calculated at the free field without adjacent piles, and then bending moments of piles investigate through conventional beam-column model. Another is CEL (Coupled Eulerian Lagrangian) approach to analyze the adjacent pile responses induced by spudcan penetration through three dimensional numerical model including spudcan, soil profile and adjacent pile. The feasibility of two approaches was verified through comparison between numerically predicted and experimentally measured results. Variations of pile bending moment induced by spudcan penetration are demonstrated with different pile length, spudcan-pile clearance and soil profiles. Comparisons of the numerically predicted pile bending moment and the experimentally measured values show that the both are close agreement for the different spudcan-pile clearance at the spudcan penetration depth of less than 15m in NC soil profiles. However, an apparent discrepancy lays on that the second positive peak bending moment from the numerical calculation by the beam-column model moves up to a higher depth than the measurement for the 40m pile length.
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Park, Taeyoon, Junhwan Jeon, Jung Kim, Sangbae Jeon, Bongjae Kim, and Dongyeon Lee. "Development of a Pile Mooring System for Large Scale FSRUs." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-19179.
Full textAbstract:
Abstract In this paper, a pile mooring system is introduced as an alternative mooring solution for FSRU. Also, the methodologies of mooring analysis and structural analysis to verify a design of pile mooring system are introduced. The mooring performance of pile mooring system can be assessed by coupled mooring analysis considering stiffness of pile, resistance of soil and hull interface mechanism. The structural integrity of pile, foundation and hull interface can be assessed by non-linear contact finite element analysis. Using these methods, the basic design of pile mooring system for 160,000-CBM large scale FSRU is developed considering practical environmental conditions.