Offshore Launching of Jack-Up Units: An Experimental Approach

2013 ◽  
Author(s):  
Claudio A. Rodríguez ◽  
Paulo T. T. Esperança ◽  
Mário Moura ◽  
Jacques Raigorodsky
Keyword(s):  
Friction Coefficient ◽  
Numerical Simulations ◽  
Experimental Approach ◽  
Offshore Structures ◽  
Model Tests ◽  
Point Of View ◽  
Operation Model ◽  
Oil Platforms ◽  
Jack Up ◽  
Structural Point

Ships and most offshore structures are commonly launched into water from dry docks. But, sometimes due to practical and economical restrictions, launching of some offshore structures takes place at floating launching platforms, usually barges. The latter type of launching is quite “usual” for jacket rigs. To assess the success of the launch operation usually numerical simulations are enough and model tests are usually not required. However, more recently, as part of the construction project of the new Brazilian jack-up oil platforms, an innovative launching operation was required: launching a jack-up using a jacket launching barge. The marked differences between the two types of structures involve hydrodynamic and structural complexities. From the hydrodynamical point of view, due to its greater volume compared to jackets, the jack-up may be subjected to greater loads as enters in water during launching, and then suffers great motions that may affect the barge motions and these, affect back, the jack-up motions. From the structural point of view, the heavier jack-up structure may cause greater stresses on the barge deck and rocker arms that should be properly addressed in order to determine the necessity for reinforcements in the jack-up and/or the barge. To assess the feasibility of this innovative launching operation, model tests were required to measure the motions of the barge and the jack-up and to evaluate the loads on the rocker arms. The present paper describes the experimental approach developed for simulating this unique launching operation. The calibration procedures are outlined and the main results of the systematic set of tests carried out are presented. Furthermore, the influence of some launching parameters such as friction coefficient, position of the center of gravity of the jack-up and initial launching angle are discussed.

Experimental Assessment of the Offshore Launching Operation of a Jack-Up Unit

2014 ◽  
Author(s):  
Claudio A. Rodríguez ◽  
Paulo T. T. Esperança ◽  
Mário Moura ◽  
Jacques Raigorodsky
Keyword(s):  
Experimental Approach ◽  
Experimental Tests ◽  
Model Tests ◽  
Experimental Assessment ◽  
Simulation Tools ◽  
Experimental Campaign ◽  
Preliminary Model ◽  
Stage 4 ◽  
Reaction Forces ◽  
Jack Up

Recently, an experimental campaign was carried out to assess the feasibility of the launching operation of two jack-up units using a barge as the launching platform. This experimental study was divided in four stages. In stages 1 to 3, a series of preliminary model tests were performed in order to provide scientific understanding of the mechanics of the operation, and investigate systematically the influence of launching parameters. The experimental approach developed for testing this operation and the results of the preliminary launching tests have been discussed in detail in a previous paper [1]. Based on the analyses of the experimental results of stages 1 to 3 and, the results of numerical simulation tools, in stage 4, a final launching condition was designed and a new set of model tests were specified to check the safety of the operation. This paper presents the results and analyses of the experimental tests in stage 4. The conditions tested in this stage covered the expected real launching condition and possible deviations in some launch parameters. The tests results include the 6-DOF motions and trajectories of the launched jack-up and the launch barge, and the reaction forces on the barge rocker arms. Later on, the success of the launching operations of P-59 and P-60 jack-up units confirmed the experimental investigation results and the feasibility of this novel launching procedure. Furthermore, it can be concluded that the experimental approach efficiently served as a tool for the assessment of high risk operations.

Assessment of a Jack-Up Offshore Launching Through Model Tests and Field Measurements

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Claudio A. Rodríguez ◽  
Paulo T. T. Esperança ◽  
Mário Moura ◽  
Jacques Raigorodsky
Keyword(s):  
Experimental Approach ◽  
Field Measurements ◽  
Experimental Tests ◽  
Model Tests ◽  
Efficient Tool ◽  
Simulation Tools ◽  
Preliminary Model ◽  
Stage 4 ◽  
Reaction Forces ◽  
Jack Up

Recently, an experimental campaign was carried out to assess the feasibility of the launching operation of two jack-up units using a barge as the launching platform. This experimental study was divided in four stages. In stages 1 to 3, a series of preliminary model tests were performed in order to provide scientific understanding of the mechanics of the operation and investigate systematically the influence of launching parameters. The experimental approach developed for testing this operation and the results of the preliminary launching tests have already been discussed in detail. Based on the analyses of the experimental results of stages 1 to 3 and the results of numerical simulation tools in stage 4, a final launching condition was designed and a new set of model tests was specified to check the safety of the operation. This paper presents the results and analyses of the experimental tests of stage 4. The conditions tested in this stage covered the expected real launching condition and possible deviations in some launch parameters. The tests results include the 6 degree-of-freedom (DOF) motions and trajectories of the launched jack-up and the launch barge, and the reaction forces on the barge rocker arms. Later on, the success of the launching operations of P-59 and P-60 jack-up units confirmed the experimental investigation results and the feasibility of this novel launching procedure. During the launching of unit P-60, field measurements were performed that confirmed that model tests as an efficient tool for the assessment of high risk operations.

An Experimental Approach for the Offshore Launching of Jack-Ups

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Claudio A. Rodríguez ◽  
Mário Moura ◽  
Paulo T. T. Esperança ◽  
Jacques Raigorodsky
Keyword(s):  
Feasibility Study ◽  
Experimental Approach ◽  
Model Tests ◽  
Building Site ◽  
Test Setup ◽  
Dry Dock ◽  
Jack Up

Recently, as part of the building contract for the new Brazilian jack-up drilling platforms, an operational challenge was raised: to launch these units from the building site, where neither dry dock nor launching ground ways exist. Economically, the best alternative was to launch these jack-ups using the available barges used commonly for jacket launch. Due to the marked differences between a jacket and a jack-up, the implementation of this novel launch operation required a careful feasibility study. Model tests were required to measure the motions of the barge and the jack-up and to evaluate the loads on the barge rocker arms. The present paper discusses the experimental approach, test setup, calibration procedures, and some results from the hydrodynamics perspective.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

Crimes against marriage and family before Criminal Code 1968

2020 ◽  
Vol 15 (1-3) ◽  
pp. 44-59
Author(s):  
Lidia Peneva
Keyword(s):  
Criminal Code ◽  
Point Of View ◽  
Marriage And Family ◽  
Historical Method ◽  
Legal Method ◽  
The Subject ◽  
The Republic ◽  
Criminal Groups ◽  
The Moment ◽  
Structural Point

Crimes against marriage and family are a particular group of social relation­ships that the law has defended properly in view of the high public significance and value they enjoy. At the moment they are regulated in Chapter VI, Section I, of the specific part of the Penal Code the Repub­lic of Bulgaria. The subject matter of this Statement will, however, be the legisla­tive provisions concerning these criminal­ized acts in retrospect. The purpose of the study is to show by historical method and through the comparatively legal method the development of these criminal groups during the periods of various criminal laws in Bulgaria. This will also provide a basis for reflection on possible de lege ferenda proposals. This report from a structural point of view will be divided into three distinct points, marking each of the penal laws in the Republic of Bulgaria, which were in force before 1968.

scholarly journals Recuperative Amino Acids Separation through Cellulose Derivative Membranes with Microporous Polypropylene Fiber Matrix

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 429
Author(s):  
Aurelia Cristina Nechifor ◽  
Andreia Pîrțac ◽  
Paul Constantin Albu ◽  
Alexandra Raluca Grosu ◽  
Florina Dumitru ◽  
...  
Keyword(s):  
Amino Acids ◽  
Cellulose Acetate ◽  
Polypropylene Fiber ◽  
Point Of View ◽  
Hydroxyethyl Cellulose ◽  
Separation Performance ◽  
Thermal Gravimetric Analyzer ◽  
Microfiltration Membranes ◽  
Ft Ir ◽  
Structural Point

The separation, concentration and transport of the amino acids through membranes have been continuously developed due to the multitude of interest amino acids of interest and the sources from which they must be recovered. At the same time, the types of membranes used in the sepa-ration of the amino acids are the most diverse: liquids, ion exchangers, inorganic, polymeric or composites. This paper addresses the recuperative separation of three amino acids (alanine, phe-nylalanine, and methionine) using membranes from cellulosic derivatives in polypropylene ma-trix. The microfiltration membranes (polypropylene hollow fibers) were impregnated with solu-tions of some cellulosic derivatives: cellulose acetate, 2-hydroxyethyl-cellulose, methyl 2-hydroxyethyl-celluloseand sodium carboxymethyl-cellulose. The obtained membranes were characterized in terms of the separation performance of the amino acids considered (retention, flux, and selectivity) and from a morphological and structural point of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) and thermal gravimetric analyzer (TGA). The re-sults obtained show that phenylalanine has the highest fluxes through all four types of mem-branes, followed by methionine and alanine. Of the four kinds of membrane, the most suitable for recuperative separation of the considered amino acids are those based on cellulose acetate and methyl 2-hydroxyethyl-cellulose.

Experimental Study of a Tanker Ship Squat in Shallow Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammadreza Fathi Kazerooni ◽  
Mohammad Saeed Seif
Keyword(s):  
Experimental Study ◽  
Shallow Water ◽  
Experimental Approach ◽  
Model Tests ◽  
Ship Hull ◽  
Experimental Results ◽  
Shallow Waters ◽  
Towing Tank ◽  
Ship Model

One of the phenomena restricting the tanker navigation in shallow waters is reduction of under keel clearance in the terms of sinkage and dynamic trim that is called squatting. According to the complexity of flow around ship hull, one of the best methods to predict the ship squat is experimental approach based on model tests in the towing tank. In this study model tests for tanker ship model had been held in the towing tank and squat of the model are measured and analyzed. Based on experimental results suitable formulae for prediction of these types of ship squat in fairways are obtained.

scholarly journals EXTREME WAVE PRESSURES AND LOADS ON A PILE-SUPPORTED WHARF DECK - INFLUENCES OF AIR GAP AND WAVE DIRECTION

2018 ◽  
pp. 5
Author(s):  
Andrew Cornett
Keyword(s):  
Offshore Structures ◽  
Model Tests ◽  
Scale Model ◽  
Extreme Waves ◽  
Wave Direction ◽  
Coastal Structures ◽  
Extreme Wave ◽  
Wave Impact ◽  
The Past ◽  
Water Depths

Many deck-on-pile structures are located in shallow water depths at elevations low enough to be inundated by large waves during intense storms or tsunami. Many researchers have studied wave-in-deck loads over the past decade using a variety of theoretical, experimental, and numerical methods. Wave-in-deck loads on various pile supported coastal structures such as jetties, piers, wharves and bridges have been studied by Tirindelli et al. (2003), Cuomo et al. (2007, 2009), Murali et al. (2009), and Meng et al. (2010). All these authors analyzed data from scale model tests to investigate the pressures and loads on beam and deck elements subject to wave impact under various conditions. Wavein- deck loads on fixed offshore structures have been studied by Murray et al. (1997), Finnigan et al. (1997), Bea et al. (1999, 2001), Baarholm et al. (2004, 2009), and Raaij et al. (2007). These authors have studied both simplified and realistic deck structures using a mixture of theoretical analysis and model tests. Other researchers, including Kendon et al. (2010), Schellin et al. (2009), Lande et al. (2011) and Wemmenhove et al. (2011) have demonstrated that various CFD methods can be used to simulate the interaction of extreme waves with both simple and more realistic deck structures, and predict wave-in-deck pressures and loads.

scholarly journals Crystallographic and structural characterization of heterometallic platinum compounds Part VII. Heterohepta- and heterooctanuclear clusters

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Milan Melnik ◽  
Peter Mikuš ◽  
Clive E. Holloway
Keyword(s):  
Structural Characterization ◽  
Structural Parameters ◽  
Bond Distance ◽  
Point Of View ◽  
Platinum Compounds ◽  
Metal Atoms ◽  
Platinum Clusters ◽  
Structural Point

AbstractThis review classifies and analyzes over fifty heterohepta- and heterooctanuclear platinum clusters. There are eight types of metal combinations in heteroheptanuclear: Pt6M, Pt5M2, Pt4M3, Pt3M4, Pt2M5, PtM6, Pt3Hg2Ru2 and Pt2Os3Fe2. The seven metal atoms are in a wide variety of arrangements, with the most common being one in which the central M atom (mostly M(I)) is sandwiched by two M3 triangles. Another arrangement often found is an octahedron of M6 atoms asymmetrically capped by an M atom. The shortest Pt-M bond distances (non-transition and transition) are 2.326(1) Å (M = Ga) and 2.537(6) Å (M = Fe). The shortest Pt-Pt bond distance is 2.576(2) Å.In heterooctanuclear platinum clusters there are eight types of metal combinations: Pt6M2, Pt4M4, Pt3Ru5, Pt2M6, PtM7, Pt2W4Ni2, PtAu6Hg and PtAu5Hg2. From a structural point of view, the clusters are complex with bicapped octahedrons of eight metal atoms prevailing. The shortest Pt-M bond distances (non-transition and transition) are 2.651(3) Å (M = Hg) and 2.624(1) Å (M = Os). The shortest Pt-Pt bond distance is 2.622(1) Å. These values are somewhat longer than those in the heteroheptanuclear clusters. Several relationships between the structural parameters were found, and are discussed and compared with the smaller heterometallic platinum clusters

Launching of Ships and Floating Structures from Horizontal Berth by Tipping Table

1998 ◽  
Vol 14 (04) ◽  
pp. 265-276
Author(s):  
Ivo Senjanovic
Keyword(s):  
Structural Dynamics ◽  
Review Paper ◽  
Offshore Structures ◽  
Model Tests ◽  
Full Scale ◽  
Strength Analysis ◽  
Test Results ◽  
Floating Structures ◽  
Measurement Results

This review paper covers extensive investigations which were undertaken in order to verify the idea of launching of ships and other floating structures from a horizontal berth by a set of turning pads. This includes structural dynamics during launching, model tests and strength analysis of the structure and the launching system. The most important results, which were used for the design of the launching system, are presented. The preparation of a barge for side launching is described, and the full-scale measurement results are compared with the test results. The advantages of building ships and offshore structures on a horizontal berth are pointed out in the conclusion.

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