Numeric modelling of vertical drains: two- and three-dimensional analyses

Author(s):  
Paulo J. Venda Oliveira ◽  
Rui F. P. M. L. Cruz ◽  
Luis. J. L. Lemos ◽  
Jorge N. V. Almeida e Sousa
2013 ◽  
Vol 50 (7) ◽  
pp. 801-804
Author(s):  
Hui Wu ◽  
Liming Hu

The Discussion revises the figure that compares different equivalent-diameter equations for prefabricated vertical drains, and the result of another equivalent equation that has been widely used in practice is also added into the figure. In addition, a three-dimensional (3D) numerical model is developed to compare with the two-dimensional (2D) numerical model used in the paper. The result indicates that the difference between the 3D and 2D models can be about 5%.


2021 ◽  
Vol 13 (3) ◽  
pp. 10-22
Author(s):  
Ahmed M. Abouhashem ◽  
Alaa El-Din A. El-Gendy ◽  
Mohamed H. Rabie ◽  
Mohamed A. Mostafa

A large-scale trial embankment provided with partially penetrating prefabricated vertical drains (PVD) was installed in consolidating marine clay deposits at East-Port said industrial zone project in Egypt. The trial embankment was constructed with a bottom area of 150x150m and a height of 5.5m to evaluate the efficiency of the improvement system and verify the design parameters. An intensive instrumentation system was built-up including shallow settlement indicators, vibrating wire piezometers, extensometer, and inclinometers. Two and three-dimensional finite element analyses (FE) were performed to study the effect of the preloading system provided with partially PVD in consolidating marine clay deposits. FE models were validated and showed good agreement with the field observations in terms of vertical displacement of embankment center, and lateral soil deformation beneath the embankment toe.


2011 ◽  
Vol 48 (6) ◽  
pp. 970-983 ◽  
Author(s):  
Xueyu Geng ◽  
Buddhima Indraratna ◽  
Cholachat Rujikiatkamjorn

This paper considers the consolidation of a layer of clay in which partially penetrating prefabricated vertical drains (PVDs) are used in conjunction with a combined surcharge and vacuum preloading. Analytical solutions for partially penetrating PVDs are derived by considering vacuum pressure (suction), time-dependent embankment surcharge, well resistance, and smear zone. Three-dimensional seepage with a virtual vertical drain is assumed to reflect real seepage into the soil beneath the tip of a PVD. Analytical solutions were then used to examine the length of the vertical drain and vacuum pressure on soft clay to determine the consolidation time and degree of consolidation, associated settlement, and distribution of suction along the drain. The proposed solutions are then employed to analyse a case history. Finally, an appropriate PVD length in relation to clay thickness and drain spacing is recommended for various loading patterns.


1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.


Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.


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