Numerical investigation of bearing capacity due to spudcan penetration in sand overlying clay

Numerical studies were carried out to investigate the bearing capacity of spudcan foundations of offshore jack-up rigs in sand overlying normally consolidated clay by using the coupled Eulerian-Lagrangian (CEL) method. The hypoplastic model was used to describe the sand, whereas the viscohypoplastic model was used to describe the clay. The illustration of the development of the shear bands due to penetration revealed the failure mechanisms of a spudcan penetrating in loose - medium-dense - dense sand overlying clay. The influence of the density of the upper sand on the bearing capacity and "punch-through" failure mechanism as well as the effect of spudcan diameter were investigated. The bearing capacity profile has been distinguished with four phases: (I) mobilization of the peak shear value of the sand layer: the first peak value may be observed in this phase; (II) mobilization of the residual shear value of the sand layer: the second peak value may be ob- served at the end of this phase; (III) reduction of the shear resistance of the sand layer because of the disappearance of the Prandtl zone; (IV) punch in the clay layer: the resistance from the upper sand layer may be neglected.

[1]  Jun Liu,et al.  Spudcan Penetration in Loose Sand Over Uniform Clay , 2009 .

[2]  D. Benson,et al.  Contact in a multi-material Eulerian finite element formulation , 2004 .

[3]  D. Benson.  Computational methods in Lagrangian and Eulerian hydrocodes , 1992 .

[4]  Jürgen Grabe,et al.  Application of a Coupled Eulerian–Lagrangian approach on geomechanical problems involving large deformations , 2011 .

[5]  Yean Khow Chow,et al.  Eulerian Finite-Element Technique for Analysis of Jack-Up Spudcan Penetration , 2012 .

[6]  Gang Qiu,et al.  Controlled installation of spudcan foundations on loose sand overlying weak clay , 2011 .

[7]  Mark Randolph,et al.  H-ADAPTIVE FE ANALYSIS OF ELASTO-PLASTIC NON-HOMOGENEOUS SOIL WITH LARGE DEFORMATION , 1998 .

[8]  Jun Liu,et al.  Numerical Simulation of the Installation and Extraction Process of Spudcan Foundations in Clay , 2009 .

[9]  Gerd Gudehus.  Physical Soil Mechanics , 2011 .

[10]  Guy T. Houlsby,et al.  Vertical bearing capacity factors for conical footings on sand , 2002 .

[11]  Jürgen Grabe,et al.  Tragverhalten von horizontal belasteten Flügelpfählen , 2009 .

[12]  Mark Randolph,et al.  Limiting cavity depth for spudcan foundations penetrating clay , 2005 .

[13]  M. Randolph,et al.  A practical numerical approach for large deformation problems in soil , 1998 .

[14]  Jun Liu,et al.  Deep Penetration of Spudcan Foundation into Double Layered Soils , 2005 .

[15]  G. G. Meyerhof,et al.  Ultimate bearing capacity of foundations on layered soils under inclined load , 1978 .

[16]  R. Butterfield,et al.  A NATURAL COMPRESSION LAW FOR SOILS (AN ADVANCE ON E-LOG P') , 1979 .

[17]  Kok Kuen Lee.  Investigation of potential spudcan punch-through failure on sand overlying clay soils , 2009 .

[18]  Chun Fai Leung,et al.  Centrifuge model study of spudcan penetration in sand overlying clay , 2010 .

[19]  K. Terzaghi.  Theoretical Soil Mechanics , 1943 .

[20]  Mark Randolph,et al.  Resistance of full-flow penetrometers in rate-dependent and strain-softening clay , 2009 .

[21]  Dimitrios Kolymbas,et al.  A rate-dependent constitutive equation for soils , 1977 .

[22]  Jiro Takemura,et al.  BEARING CAPACITY PREDICTIONS OF SAND OVERLYING CLAY BASED ON LIMIT EQUILIBRIUM METHODS , 1998 .

[23]  S. Henke,et al.  Influence of pile installation on adjacent structures , 2009 .

[24]  L. M. Kraft,et al.  Bearing capacity of shallow footing, sand over clay , 1983 .

[25]  Andrzej Niemunis,et al.  VISCOUS BEHAVIOUR OF SOIL UNDER OEDOMETRIC CONDITIONS , 1996 .

[26]  Teh Kar Lu.  Punch-through of spudcan foundation in sand overlying clay , 2008 .

[27]  Jürgen Grabe,et al.  Explicit modeling of cone and strip footing penetration under drained and undrained conditions using a visco‐hypoplastic model , 2011 .

[28]  P. V. Wolffersdorff,et al.  A hypoplastic relation for granular materials with a predefined limit state surface , 1996 .

[29]  Jürgen Grabe,et al.  Numerical investigation of soil plugging inside open-ended piles with respect to the installation method , 2008 .

[30]  Wai-Fah Chen,et al.  Bearing Capacity of Shallow Foundations , 1991 .

[31]  G. G. Meyerhof.  Ultimate Bearing Capacity of Footings on Sand Layer Overlying Clay , 1974 .

[32]  Gerd Gudehus,et al.  Determination of parameters of a hypoplastic constitutive model from properties of grain assemblies , 1999 .

[33]  W. H. Craig,et al.  Deep penetration of spud-can foundations on sand and clay , 1990 .

[34]  Mark Randolph,et al.  New Mechanism-Based Design Approach for Spudcan Foundations on Single Layer Clay , 2009 .

[35]  Chun Fai Leung,et al.  A comparison of the bearing capacity of flat and conical circular foundations on sand , 2008 .

[36]  Chun Fai Leung,et al.  Revealing the bearing capacity mechanisms of a penetrating spudcan through sand overlying clay , 2008 .

[37]  G. Qiu,et al.  3D FE analysis of the installation process of spudcan foundations , 2010 .

[38]  Ryan Phillips,et al.  Scale Effect of Strip and Circular Footings Resting on Dense Sand , 2001 .

[39]  Harvey J. Burd,et al.  BEARING CAPACITY OF PLANE-STRAIN FOOTINGS ON LAYERED SOILS , 1997 .

[40]  G. G. Meyerhof,et al.  Design charts for ultimate bearing capacity of foundations on sand overlying soft clay , 1980 .

[41]  Mark Randolph,et al.  Deep-penetrating spudcan foundations on layered clays: numerical analysis , 2010 .

[42]  M. J. Rattley,et al.  Uplift Performance of Transmission Tower Foundations Embedded in Clay , 2008 .