Determination of the ultimate consolidation settlement of jack-up spudcan footings embedded in clays

2021 ◽  
Vol 236 ◽  
pp. 109509
Author(s):  
Jiang Tao Yi ◽  
Fei Liu ◽  
Tai Bin Zhang ◽  
Zi Zhan Qiu ◽  
Xi Ying Zhang
Keyword(s):  
Consolidation Settlement ◽  
Jack Up

scholarly journals Numerical investigation of prediction method for spudcan settlement in normally consolidated kaolin clay

2020 ◽  
Vol 319 ◽  
pp. 06002
Author(s):  
Z Z Qiu ◽  
J T Yi
Keyword(s):  
Prediction Method ◽  
Soil Parameters ◽  
Centrifuge Tests ◽  
Operational Load ◽  
Modified Cam Clay ◽  
Consolidation Settlement ◽  
Parametric Studies ◽  
Dual Stage ◽  
Jack Up ◽  
Cam Clay

The post-installation consolidation settlement of spudcan foundations is an issue of concern for the offshore jack-up industry, especially when jack-up rigs operate for a long period such as those serving as production units. Although many centrifuge tests or numerical calculations have been conducted for spudcan behaviour after consolidation, there are no guidelines available to predict the consolidation settlement development. This paper reports a study dedicated to this subject. The spudcan installation and consolidation under operational load was continually simulated through the dual-stage Eulerian-Lagrangian analyses incorporating the modified Cam-clay model. Its feasibility and reliability were verified by comparison with other experimental results in literature. Parametric studies were carried out for spudcans under various soil parameters and geometrical conditions. A suitable method, Hyperbolic method, is proposed to predict spudcan settlement during consolidation with observed data.

The post-installation consolidation settlement of jack-up spudcan foundations in clayey seabed soils

2020 ◽  
Vol 123 ◽  
pp. 103611
Author(s):  
Jiang Tao Yi ◽  
Yu Tao Pan ◽  
Zi Zhan Qiu ◽  
Fei Liu ◽  
Xi Ying Zhang ◽  
...  
Keyword(s):  
Consolidation Settlement ◽  
Jack Up

scholarly journals Determination of Pre-Consolidation Pressure by Different Method

2021 ◽  
Vol 10 (1) ◽  
pp. 36-43
Author(s):  
Nazile Ural ◽  
Uğur Küçüker
Keyword(s):  
Preparation Method ◽  
Sand Content ◽  
Stress History ◽  
Fine Grained ◽  
Consolidation Pressure ◽  
Effect Of Water ◽  
Consolidation Settlement ◽  
Over Time ◽  
Properties Of Soil

 One of the most important soil problems seen on fine-grained soils is the settlement problem. The primary consolidation settlement shows itself over time with the effect of water. Also, the settlement properties of soil change depending on the stress history. In this study, silt mixtures with three different sand percentages were prepared using the slurry sludge preparation method under 50kPa load, and pre-consolidation pressures were calculated by performing the oedometer experiment on the obtained samples. Using the collected oedometer data, the pre-consolidation pressures were calculated and compared by six different methods. As a result, the results equal to the vertical stress values applied for the three mixtures were obtained by Butterfield and Tavenas methods. Sand content was effective in Casagrande, Van Zelst, and Janbu methods, but not in Butterfield, Tavenas, and Shmertman.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.

Models of Thermodynamic Properties of Prominences

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey
Keyword(s):  
Thermodynamic Properties ◽  
Mass Transport ◽  
Emission Spectrum ◽  
Thermodynamic Parameters ◽  
Working Group ◽  
Physical Processes ◽  
Theoretical Concepts ◽  
Group 3 ◽  
Observational Techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

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