Effect of Surface Heave on Response of Partially Embedded Pipelines on Clay

The as-laid embedment of an on-bottom pipeline strongly influences the resulting thermal insulation, and the resistance to subsequent axial and lateral movement of the pipeline. Reliable assessment of these parameters is essential for the design of offshore pipelines. Static vertical penetration of a pipe into a soft clay seabed—which can be modeled as an undrained process—causes heave of soil on each side of the pipeline. The heaved soil contributes to the vertical penetration resistance and the horizontal capacity. This paper describes a series of large deformation finite-element analyses of pipe penetration, supported by a simple analytical assessment of the heave process. The conventional bearing capacity approach to the analysis of pipe penetration is reviewed, and modifications for the effects of soil weight and heave are presented. It is shown that in soft soil conditions—which are typical for deep water—the soil self-weight contributes a significant portion of the vertical penetration resistance a...

[1]  Mark Randolph,et al.  Seabed Characterisation And Models For Pipeline-Soil Interaction , 2007 .

[2]  D. Cathie,et al.  Pipeline geotechnics – state-of-the-art , 2005 .

[3]  Mark Randolph,et al.  The ultimate undrained resistance of partially embedded pipelines , 2008 .

[4]  Mark Randolph,et al.  Upper-bound yield envelopes for pipelines at shallow embedment in clay , 2008 .

[5]  Malcolm D. Bolton,et al.  Pipe-Soil Interaction With Flowlines During Lateral Buckling and Pipeline Walking - The SAFEBUCK JIP , 2008 .

[6]  Malcolm D. Bolton,et al.  Pipe-Soil Interaction during Lateral Buckling and Pipeline Walking — The SAFEBUCK JIP , 2008 .

[7]  John P. Carter,et al.  The Bearing Capacity of Clays Weakened by Fissures , 1996 .

[8]  J. D. Murff,et al.  PIPE PENETRATION IN COHESIVE SOIL , 1989 .

[9]  Charles Aubeny,et al.  Collapse Loads for a Cylinder Embedded in Trench in Cohesive Soil , 2005 .

[10]  G.J.M. Schotman,et al.  PIPE-SOIL INTERACTION: A MODEL FOR LATERALLY LOADED PIPELINES IN CLAY , 1987 .

[11]  Michael C. Georgiadis,et al.  DISPLACEMENTS OF FOOTINGS ON SAND UNDER ECCENTRIC AND INCLINED LOADS , 1988 .

[12]  Mark Randolph,et al.  Bearing capacity and large penetration of a cylindrical object at shallow embedment , 2005 .

[13]  Rodrigo Salgado,et al.  Two- and three-dimensional bearing capacity of foundations in clay , 2004 .

[14]  S. Gourvenec Effect of embedment on the undrained capacity of shallow foundations under general loading , 2008 .

[15]  Alec Westley Skempton,et al.  The bearing capacity of clays , 1951 .

[16]  R. Nova,et al.  Settlements of shallow foundations on sand , 1991 .

[17]  Mark Randolph,et al.  Combined loading of skirted foundations , 1998 .

[18]  W. A. Take,et al.  Soil deformation measurement using particle image velocimetry (PIV) and photogrammetry , 2003 .

[19]  Chris M. Martin,et al.  Upper-bound analysis of lateral pile capacity in cohesive soil , 2006 .

[20]  L. Prandtl,et al.  Bemerkungen über die Entstehung der Turbulenz , 1921 .

[21]  Mark Randolph,et al.  Analysis of the undrained breakout resistance of partially embedded pipelines. , 2007 .

[22]  Christophe Gaudin,et al.  Mechanisms of pipe embedment and lateral breakout on soft clay , 2008 .

[23]  Mark Randolph,et al.  MODELING OF SHALLOWLY EMBEDDED OFFSHORE PIPELINES IN CALCAREOUS SAND , 2002 .

[24]  Mark Randolph,et al.  THE EFFECT OF EMBEDMENT DEPTH ON THE UNDRAINED RESPONSE OF SKIRTED FOUNDATIONS TO COMBINED LOADING , 1999 .

[25]  L. Prandtl,et al.  Hauptaufsätze: Über die Eindringungsfestigkeit (Härte) plastischer Baustoffe und die Festigkeit von Schneiden , 1921 .