0
Research Papers: Offshore Geotechnics

Experimental Investigation of Pile Installation by Vertical Jet Fluidization in Sand

[+] Author and Article Information
Larissa de Brum Passini

Department of Civil Engineering,
Federal University of Rio Grande do Sul,
Porto Alegre,
Rio Grande do Sul 90035-190, Brazil
e-mail: larissapassini@hotmail.com

Fernando Schnaid

Professor
Department of Civil Engineering,
Federal University of Rio Grande do Sul,
Porto Alegre,
Rio Grande do Sul 90035-190, Brazil
e-mail: fschanid@gmail.com

1Corresponding author.

Contributed by the Ocean, Offshore, and Arctic Engineering Division of ASME for publication in the JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING. Manuscript received December 19, 2014; final manuscript received May 25, 2015; published online June 16, 2015. Assoc. Editor: Solomon Yim.

J. Offshore Mech. Arct. Eng 137(4), 042002 (Aug 01, 2015) (10 pages) Paper No: OMAE-14-1151; doi: 10.1115/1.4030707 History: Received December 19, 2014; Revised May 25, 2015; Online June 16, 2015

The paper examines the mechanism of pile installation by vertical jet fluidization in saturated sand in order to define the constitutive parameters that control installation geometry and pile depth of embedment. A series of laboratory model tests representative of offshore torpedo piles was carried out using downwardly directed vertical water jets in both medium and dense sands. Measurements from model tests at three different scales indicate that the geometry of fluidized cavities is not influenced by the initial density of the sand and that the perturbed zone is constrained to a distance of about two pile diameters from the pile centerline during pile installation. Following the laws of dimensional analysis, an expression for the embedment of fluidized piles is derived and shows that penetration depth is a function of pile weight and geometry, fluidized water jet flow rate and velocity, as well as the soil and fluid properties. Penetration is shown to increase with increasing flow rate and pile weight and decreasing soil relative density. Although the results have to be validated by tests at larger scales to prove compatibility with the full-scale behavior, model tests indicate maximum embedment depth of the order of 50 times the pile diameter.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Grain-size distribution

Grahic Jump Location
Fig. 2

Experimental setup

Grahic Jump Location
Fig. 3

Schematic representation of fluidization geometry in (a) suspended tubes STs and (b) free-fall tubes FTs

Grahic Jump Location
Fig. 4

Schematic representations from lateral tests for (a) the installation process during penetration and (b) the enlargement of the fluidized zone (after penetration)

Grahic Jump Location
Fig. 5

Fluidized zone (dh/de) versus pile penetration (L) from lateral tests in FTs and STs at Dr = 50% and 90%

Grahic Jump Location
Fig. 6

Pile fluidization in fine sand: (a) de = 14.0 mm; dj = 9.7 mm; mB = 275 g; Qo = 1.0 × 10−3 m3/min; Dr = 50%, (b) de = 16.2 mm; dj = 11.6 mm; mB = 400 g; Qo = 1.0 × 10−3 m3/min; Dr = 90%, and (c) de = 21.3 mm; dj = 16.2 mm; mB = 960 g; Qo = 1.6 × 10−3 m3/min; Dr = 50%

Grahic Jump Location
Fig. 7

Parameters controlling (a) constant and (b) discontinuous penetration

Grahic Jump Location
Fig. 8

Model test results expressed as (a) tip displacement and versus time and (b) tip velocity versus time

Grahic Jump Location
Fig. 9

Pile load–penetration curves without fluidization: (a) dimension and (b) dimensionless results for Dr = 50% and 90%

Grahic Jump Location
Fig. 10

Pile penetration expressed as a function of (a) flow rate and (b) jet velocity for Dr = 50%

Grahic Jump Location
Fig. 11

Pile penetration plotted against (a) flow rate and (b) jet velocity for Dr = 50% and 90%

Grahic Jump Location
Fig. 12

Dimensionless groups Π1 versus Π2 and Π3

Grahic Jump Location
Fig. 13

Comparison between measured and predicted normalized penetration depth Π1

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In