Frontiers in Offshore Geotechnics III

Frontiers in Offshore Geotechnics III comprises the contributions presented at the Third International Symposium on Frontiers in Offshore Geotechnics (ISFOG, Oslo, Norway, 10-12 June 2015), organised by the Norwegian Geotechnical Institute (NGI). The papers address current and emerging geotechnical engineering challenges facing those working in offshore construction, design and research. Keynote papers with authors from industry and academia describe the state-ofthe-art in practice and theory, and a further 191 peer-reviewed papers describe emerging research, new design techniques and recent case studies related to the frontiers of offshore geotechnical engineering.

The themes of the papers include:
? Geohazards;
? Soil characterisation, modelling and testing techniques;
? Shallow, caisson and pile foundation technology;
? Anchoring solutions;
? Well, conductor and pipeline geotechnics;
? Jack-up unit spudcan behaviour, and;
? Reliability-based and performance-based geotechnical design.

New and existing design methods and industry best practices are presented together with innovative technologies and emerging research ideas derived from a variety of numerical and theoretical investigations, experimental programmes and field experience. Frontiers in Offshore Geotechnics III provides a comprehensive state-of-the-art reference for professionals and researchers in offshore, civil and maritime engineering and for soil mechanics specialists.

Preface
Committees
Reviewers
Sponsors

Volume 1

The Third ISSMGE McClelland Lecture

Introduction to Knut H. Andersen, The Third ISSMGE McClelland Lecturer

Cyclic soil parameters for offshore foundation design
K.H. Andersen

Keynotes

The suction foundation technology
T.I. Tjelta

Geotechnics for wells top-hole section and conductor
P. Jeanjean, A. Zakeri, Z. Al-Khafaji, K. Hampson, E. Clukey & E. Liedtke

The effects of pile ageing on the shaft capacity of offshore piles in sand
K. Gavin, R. Jardine, K. Karlsrud & B. Lehane

A FE procedure for calculation of cyclic behaviour of offshore foundations under partly drained conditions
H.P. Jostad, G. Grimstad, K.H. Andersen & N. Sivasithamparam

Geohazard risk evaluation and related data acquisition and sampling program for the methane hydrate offshore production test
K. Yamamoto, Y. Nakatsuka, R. Sato, T.J. Kvalstad, K. Qiu & R. Birchwood

Deterministic and probabilistic advances in the analysis of spudcan behaviour
M. Cassidy, J. Li, P. Hu, M. Uzielli & S. Lacasse

Suction anchors and caissons

Installation of suction caissons for an asymmetrical support structure in sandy soil
E.A. Alderlieste & E.A. van Blaaderen

Simplified earthquake analysis for wind turbines and subsea structures on closed caisson foundations
C. Athanasiu, A. Bye, J. Tistel, A.G. Ribe, K. Arnesen, S. Feizikhanhandi & E. Sørlie

Laterally loaded suction caissons with aspect ratio of one
C.-H. Chen, R.B. Gilbert, H. Gerkus, A.A. Saleh & L. Finn

Seismic response of bucket foundations for offshore wind tower using dynamic centrifuge tests
Y.W. Choo, S.G. Yang, K. Lee, Y. Kim, K. Bae, B.M. Jin & N.R. Kim

Friction degradation and strength regain along suction piles in soft deepwater Gulf of Guinea clays
J.L. Colliat

Suction pile foundation for a PLET subsea structure
A. Foresi & S. Bughi

Suction caisson extraction resistance in Gulf of Guinea clay
C. Gaudin, M.F. Randolph, S. Gourvenec, C.D. O’Loughlin, D.J. White & J.-L. Colliat

Performance of a shallow skirted foundation for TLP mooring in carbonate silt
S.M. Gourvenec, S. Neubecker, M. Senders, D.J. White, C. Gaudin & C.D. O’Loughlin

Calculation of undrained holding capacity of suction anchors in clays
H.P. Jostad & K.H. Andersen

Interpretation of centrifuge tests of suction anchors in reconstituted soft clay
H.P. Jostad, K.H. Andersen, H.D.V. Khoa & J.L. Colliat

CAISSON_VHM: a program for caisson capacity under VHM load in undrained soils
S. Kay

Suction anchor geotechnical design practice: A case study
J. Kennedy, J. Oliphant, A. Maconochie, B. Stuyts & D. Cathie

Centrifuge model test for bearing capacity evaluation of hybrid suction foundation on clay under vertical and horizontal loads
J.H. Kim, S.R. Kim, D.S. Kim, K.Y. Lee, J.U. Youn, D.J. Kim & S.H. Jee

Pullout resistance of horizontal and inclined loaded suction anchor installed in silty sand via centrifuge modelling
S. Kim, J.-H. Kim, D.-S. Kim & Y.W. Choo

Skirt penetration resistance in carbonate soils from the CPT
B.M. Lehane, S. Elkhatib & P. Brunning

Horizontal capacity of multiple suction anchors using numerical analysis
S.H. Na, I.S. Jang, M.H. Oh & O.S. Kwon

Dynamic behaviour of mono bucket foundations subjected to combined transient loading
S.D. Nielsen, L.B. Ibsen & B.N. Nielsen

Novel monitoring solutions solving geotechnical problems and offshore installation challenges
P. Sparrevik & J.M. Strout

Effect of torsion on suction piles for subsea and mooring applications
H. Suroor & J. Hossain

Comparison of design methods for axially loaded buckets in sand
E. Vaitkunaite, B.N. Nielsen & L.B. Ibsen

Caisson capacity in undrained soil: Failure envelopes with internal scooping
B.F.J. van Dijk

P–y curves for bucket foundations in sand using finite element modeling
M.U. Østergaard, B.S. Knudsen & L.B. Ibsen

Pipelines, risers and subsea earthworks

Seabed stiffness model for steel catenary risers
C.P. Aubeny, T.A. White, T. Langford, V. Meyer & E.C. Clukey

Ultimate uplift capacity of buried pipelines in undrained clay
J.-C. Ballard & C.C. Smith

Evaluation of a toroid for model pipeline testing of very soft offshore box core samples
A.G. Boscardin & D.J. DeGroot

Excess pore pressure redistribution beneath pipelines: FEA investigation and effects on axial pipe-soil interaction
D. Carneiro, D.J. White, F.A.B. Danziger & G.B. Ellwanger

Pipeline embedment and consolidation beneath on-bottom pipe model in kaolin clay
R. Carroll

The soil strength degradation influence in the axial pipe-soil resistance
C.O. Cardoso, C.S. Amaral & V.T. Ochi

Pipe-Soil Interaction: Recent and future improvements in practice
A.J. Hill & D.J. White

Predicted and observed settlements of a subsea rock installation – comparison between field measurements and FE simulations of soft North Sea clay
M. Kahlström, R. Frossard & H. Mattsson

Effects of different loading time histories on fatigue design of steel catenary risers using nonlinear riser-soil interaction models
M. Kimiaei & J. Liao

A new torsional shear device for pipeline interface shear testing
M.Y.-H. Kuo, C.M. Vincent, M.D. Bolton, A. Hill & M. Rattley

Large scale experiments on the riser-soil interaction in clay
K. Li, L.Wang & F. Yuan

An integrated approach to pipeline burial in the 21st century – The current state-of-the-art
A. Maconochie, J. Kennedy & J. Oliphant

Direct shear interface tests for pipe-soil interaction assessment
V.M. Meyer, R. Dyvik & D.J. White

Evaluation of pipe-soil interaction in liquefied soil
A. Murianni, O. Zanoli & E.J. Parker

Pipe-soil interaction under rapid axial loading
V. Smith & A.M. Kaynia

Mechanical trencher modelling in hard ground: State-of-the-art
B. Stuyts, D. Cathie, C. Guyatt, P. Boyde & J. Pyrah

Finite element analysis of soil damping for pipeline slugging
J.S. Templeton III, M.J. Barrett & E.C. Clukey

Geotechnical considerations for pipeline stabilization design using rock berms
J.G. Tom, H. Zhou &A.D. Deeks

Pipe-soil interaction mechanism during pipeline upheaval buckling in loose saturated sand
J.Wang, S.K. Haigh & N.I. Thusyanthan

Study of vertical pipe-soil interaction based on Coupled Eulerian-Lagrangian method
K.Wang, R. Shi & L.Wang

Stress level effects on plane-strain pipe uplift resistance
E.S.Williams, B.W. Byrne & A. Blakeborough

Theoretical analysis and model test for pipeline protection from dragged anchors
S. Yan, B. Guo, L. Sun & Z. Lei

A discrete element study on upheaval ratcheting behavior of pipelines buried in sand
L. Yu, H. Zhang & J. Liu

An investigation on existing nonlinear seabed models for riser-fluid-soil interaction studies in steel catenary risers
E. Zargar & M. Kimiaei

Geotechnical design and construction aspects of a pipeline-escarpment crossing
J. Zhang, C. Erbrich, I. Finnie, S. Neubecker, D.J. White, A.D. Deeks, G. Doh, G. Gumming, W. Op den Velde, N. Brown & R. Little

Piled foundations

Modelling of laterally loaded screw piles with large helical plates in sand
T.A. Al-Baghdadi, M.J. Brown, J.A. Knappett & R. Ishikura

Design methodology for cyclically and axially loaded piles in chalk forWikinger OWF
A.H. Augustesen, C.T. Leth, M.U. Østergaard, M. Møller, J. Dührkop & P. Barbosa

Full scale offshore verification of axial pile design in chalk
P. Barbosa, M. Geduhn, R. Jardine, F. Schroeder & M. Horn

Centrifuge investigation of the axial cyclic behaviour of a single pile used for the foundation of a jacket type offshore wind turbine
M. Blanc, L. Thorel, R. Isorna, C. Dano, P. Kotrnois & M. Philippe

Review of pile driving results for the M¯aui and Maari developments in the Taranaki basin of New Zealand
P. Brunning, F.C. Chow, A. Keep, J. Thomas, D. Yong & D. Pennington

Cyclic pile load tests combined with laboratory results to design offshore wind turbine foundations in chalk
J. Dührkop, A.H. Augustesen & P. Barbosa

Comparison of pile bearing capacity from CPT and dynamic load tests in clay considering soil setup
K. Fakharian & M.R. Khanmohammadi

The use of pipe piles for creating ice protection barrier
V.B. Glagovsky, S.A. Sosnina & I.N. Shatalina

Improvement of bearing capacity of vibratory driven open-ended tubular piles
J. Grabe & T. Pucker

Small strain overlay to the API p-y curves for sand
S.B. Hanssen

Boulder-soil-pile dynamic interaction
A. Holeyman, P. Peralta & N. Charue

Driven pile design in weak rock
J. Irvine, V. Terente, L.T. Lee & R. Comrie

Effect of soil set-up during interruption of offshore pile driving
A. Jahr &T. Tefera

Axial capacity design practice for North European wind-turbine projects
R.J. Jardine, N.V. Thomsen, M. Mygind, M.A. Liingaard & C.L. Thilsted

Lessons learned from pile driving and monitoring in gravels on the Northstar Artificial Island
P. Jeanjean, D. Miller, H. Brooks & M. Yogendrakumar

Innovative design of foundations – offshore wind farm substation
L. Kellezi, S. Sundararajan & O. Koreta

A preliminary experimental study on the mechanism of local scour at pile groups in steady currents
F. Liang, C.Wang, Y.Wang & M. Huang

Interpretation difficulties of pile set-up in sand
J.K. Lim & B.M. Lehane

Evolution of driving resistance during driven pile installation
R. Liu, S.W. Yan & P. Basu

CPT-based pile shaft friction in calcareous sands of western Indian offshore
R. Mahanta, R.K. Ghanekar & A. Kumar

Synthesis of pile driving data in South East Asia
E. Nicolini, I. Haghighi & J.L. Colliat-Dangus

Case studies – predicting soil resistance to driving in South East Asia
C.R. Parthasarathy, G. Ramesh & K. Nikita

Axial capacity ageing trends of piles driven in silica sands
S.P. Rimoy & R.J. Jardine

In situ and laboratory tests in dense sand investigating the helix-to-shaft ratio of helical piles as a novel offshore foundation system
G. Spagnoli, K. Gavin, C. Brangan & S. Bauer

Re-assessment of pile driveability predictions on sites offshore Nigeria
B. Vignerot, R.Wallerand, M. Maron & D. Colliard

Numerical implementation of soil-pile interaction models for monotonic and reversed axial loading
A.F.Witthoeft, X. Long & K.-M. Tjok

Ultimate lateral resistance of laterally loaded piles in undrained clay
J. Yu, M. Huang & C. Zhang

Deepwater jetted piles: Numerical modeling of jetting action and axial bearing capacity
A. Zakeri,W.O. McCarron, E.C. Clukey, E. Liedtke & P. Jeanjean

Centrifuge model tests on laterally monotonic and cyclic pile-soil interaction of a tetrapod jacket foundation
B. Zhu, T. Li & J. Ren

Monopiles

Model pile response to multi-amplitude cyclic lateral loading in cohesionless soils
C.N. Abadie, B.W. Byrne & S. Levy-Paing

On the development of a hybrid foundation for offshore wind turbines
I. Anastasopoulos & M. Theofilou

Alternative p-y curve formulations for offshore wind turbines in clays
M. Arroyo, D. Abadías & M. Coelho

Improving the lateral resistance of offshore pile foundations for deepwater application
H.S. Arshi & K.J.L. Stone

New design methods for large diameter piles under lateral loading for offshore wind applications
B.W. Byrne, R. McAdam, H.J. Burd, G.T. Houlsby, C.M. Martin, L. Zdravkovic, D.M.G. Taborda, D.M. Potts, R.J. Jardine, M. Sideri, F.C. Schroeder, K. Gavin, P. Doherty, D. Igoe, A. MuirWood, D. Kallehave & J.S. Gretlund

Cyclic lateral loading of monopiles for offshore wind turbines
A.E. Haiderali, M. Nakashima & S.P.G. Madabhushi

Observed variations of monopile foundation stiffness
D. Kallehave, C.L. Thilsted & A. Troya

Design of large diameter monopiles in chalk atWestermost Rough offshore wind farm
A. MuirWood, B. Mackenzie, D. Burbury, M. Rattley, C.R.I. Clayton, M. Mygind, K.W. Andersen, C.L. Thilsted & M.A. Liingaard

Influence of vertical loads on the behavior of laterally loaded large diameter pile in sand
L.L. Mu, M.S. Huang, J. Zhang & C.M. Feng

Predicting monopile behaviour for the GodeWind offshore wind farm
F.C. Schroeder, A.S. Merritt, K.W. Sørensen, A. MuirWood, C.L. Thilsted & D.M. Potts

Evaluation of a new p-y approach for piles in sand with arbitrary dimensions
K. Thieken, M. Achmus & K. Lemke

Experimental trends from lateral cyclic tests of piles in sand
P. Truong & B.M. Lehane

Effect of relative pile’s stiffness on lateral pile response under loading of large eccentricity
V. Zania, O. Hededal & R.T. Klinkvort

Numerical modelling of large diameter piles under lateral loading for offshore wind applications
L. Zdravkovi´c, D.M.G. Taborda, D.M. Potts, R.J. Jardine, M. Sideri, F.C. Schroeder, B.W. Byrne, R. McAdam, H.J. Burd, G.T. Houlsby, C.M. Martin, K. Gavin, P. Doherty, D. Igoe, A. MuirWood, D. Kallehave & J.S. Gretlund

Author index

Volume 2

Shallow foundations

Prediction and worked example for a sliding foundation on soft clay
S. Bretelle

Effects of drainage on the response of a sliding subsea foundation
M.L. Cocjin, S.M. Gourvenec, D.J. White & M.F. Randolph

Undrained bearing capacity of skirted mudmats on inclined seabeds
H.P. Dunne, C.M. Martin, L. Muir, N. Brown & R.Wallerand

Three-dimensional limit analysis of rectangular mudmat foundations
C.M. Martin, H.P. Dunne, R.Wallerand & N. Brown

Collision of double hull tanker with gravity base foundation of offshore wind turbine: case of horizontal drift and swell D. Osthoff & J. Grabe

Some key aspects in geotechnical design of GBS foundations on sand
H.J. Pederstad, D.A. Kort & F. Nowacki

A framework for the design of sliding mudmat foundations
B. Stuyts, R.Wallerand & N. Brown

Undrained vertical bearing capacity of perforated shallow foundations
L. Tapper, C.M. Martin, B.W. Byrne & B.M. Lehane

Simulation of a full-scale test on a gravity base foundation for offshore wind turbines using a high cycle accumulation model
H. Zachert, T.Wichtmann, Th. Triantafyllidis & U. Hartwig

System integration of direct on-seabed sliding foundations
H. Zhou, H. Krisdani, R. Maujean & A.D. Deeks

Anchoring systems

Pullout capacity of plate anchors in sand for floating offshore wind turbines
A.S. Bradshaw, J. Giampa, F. Dietrich, R. Gilbert & H. Gerkus

Centrifuge model study on pullout behavior of plate anchors in clay with linearly increasing strength
J. Chen, C.F. Leung, Z. Chen, K.K. Tho & Y.K. Chow

Large deformation numerical analysis of plate anchor keying process
Z. Chen, K.K. Tho, C.F. Leung & Y.K. Chow

The role of partly remoulded clay in fluke and plate anchor design
R. Dahlberg & S. Rességuier

Numerical modeling of drag anchors of floating structures – comparison of ultimate holding capacity with limit equilibrium methods
A.V. da Fonseca & H. Dias

Design and performance of suction embedded plate anchors
C. Gaudin, Y. Tian, M.J. Cassidy, M.F. Randolph, D.Wang & C.D. O’Loughlin

Soil flow mechanism around deeply embedded plate anchors during monotonic and sustained uplifts
C. Han, D.Wang, C. Gaudin, C.D. O’Loughlin & M.J. Cassidy

Comparison between FEM analyses and full-scale tests of fluke anchor behavior in silty sand
K. Heurlin, S. Rességuier, D. Melin & K.R. Nilsen

Dynamically Installed Anchors: Performance of embedded mooring chain profile in clay
Y. Kim, M.S. Hossain & D.Wang

A review of anchor technology for floating renewable energy devices and key design considerations
J.A. Knappett, M.J. Brown, H. Aldaikh, S. Patra, C.D. O’Loughlin, S.H. Chow, C. Gaudin & J.T. Lieng

Numerical modelling of the SEPLA during keying process
L. Li, F. Yuan, L.Wang & Z. Guo

Behavior of Suction Embedded Plate Anchors with flap during keying in clay
J. Liu, L. Lu, M. Li & L. Yu

Chain configuration in sand, theory and large scale field testing
N. Mortensen

Cyclic response of shallow helical anchors in a medium dense sand
J.T. Newgard, J.A. Schneider & D.J. Thompson

Numerical investigation on line tension-induced pore pressure accumulation around an embedded plate anchor
K. Shen, Z. Guo & L.Wang

Behaviour of OMNI-Max anchors under chain loading
Q.Wei, Y. Tian, M.J. Cassidy, C. Gaudin & C.D. O’Loughlin

Geohazards and integrated studies

Predictions of ice scour loads from small scale tests under 1 g conditions
S. Arnau & A. Ivanovic

Areas 2 and 5 offshore Mozambique: Mass-movements on a deep-water margin with scant adjacent shelf
S.G. Ayers & I.P. Hughes

Turbidity current hazard assessment for field layout planning
M.A. Clare, S. Thomas, M. Cartigny & M. Mansour

Bayesian mechanistic imaging of two-dimensional heterogeneous elastic media from seismic geophysical observations
S. Esmailzadeh, Z. Medina-Cetina, J.W. Kang & L.F. Kallivokas

Optimization of deep-water pipeline routes in areas of geologic complexity – an example from the Southern Gulf of Mexico
W.C. Haneberg, C.A. Devine, D.N.V. Feregrino & M.O. Calderón

Understanding the element of time in probabilistic submarine slope stability analyses
W.C. Haneberg

Effect of fines on mechanical properties of methane hydrate bearing sands
M. Hyodo, S. Kajiyama, A. Kato, A. Nishimura, Y. Nakata & N. Yoshimoto

Numerical analysis of submarine debris flows based on critical state soil mechanics
T. Kobayashi, K. Soga & P. Dimmock

The life cycle of geohazards within an offshore engineering development
A. Lane & S. Tyler

Numerical analysis of stability of seafloor slope under linear waves
T.K. Nian, B. Liu, D.Wang, L. Song & M. Liu

Offshore 1D infinite slope modeling in seismic conditions with OpenSees
C. Piatti, L. Zuccarino & O. Zanoli

Numerical simulations of shallow gas migration in vicinity of platforms in offshore Malaysia: Effects of relief wells on excess pore pressure dissipation
M.J. Rohani, A.N. Norhuda, D. Tami, J.C. Choi & T. Lunne

Geotechnology – Converting site investigations into 3D geotechnical models
M. Sienko, K.L. Kaufmann, R.B. Jørgensen, A. Almholt, J. Dührkop & M. Geduhn

Weak interlayers effects on seismic performance of a deepwater slope
A.C. Trandafir & M.E. Popescu

Integration of very-high-resolution seismic and CPTU data from a coastal area affected by shallow landsliding – the Finneidfjord natural laboratory
M. Vanneste, C.F. Forsberg, S. Knudsen, T.J. Kvalstad, J.-S. L’Heureux, T. Lunne, M.E. Vardy, S. Chand, O. Longva, E. Morgan, A. Kopf, T. Mörz, A. Steiner, J. Brendryen & H. Haflidason

Influence of gas hydrate dissociation on mechanical properties of gas hydrate-bearing sediment
W. Zhang, Q. Li, Y. Li & H. Cun

Soil characterisation and modelling

Effect of pore pressure build-up on the seismic response of sandy deposits
F. Ardoino, D. Bertalot, C. Piatti & O. Zanoli

Potential of estimating relative density by measuring shear wave velocity in field and in laboratory
T. Biryaltseva, S. Kreiter, T. Moerz & T. Lunne

Strength of a carbonate silt at the solid-fluid transition and submarine landslide run-out
N. Boukpeti, D.J. White, M.F. Randolph & N.P. Boylan

Results of geotechnical characterization in the laboratory of clays from offshore Mozambique
L. Brant, R. Sancio, L. Jen & N. Summer

Temperature effects on laboratory measured strength on deep water soft clays
C.S. Gue, T. Lunne & S. Perkins

Procedures for estimating hysteretic foundation damping
J.A.T. Johansson, F. Løvholt & C. Madshus

Development of nonlinear foundation springs for dynamic analysis of platforms
A.M. Kaynia & K.H. Andersen

Planning of soil investigation for GBS foundation design
D.A. Kort, H.J. Pederstad & F. Nowacki

Characterization of in-situ effective stress profiles in clays based on piezo-cone penetration test (CPTU) results
J. Lee, D. Park, D. Kyung, D. Park & I. Kim

New standards and practice of Arctic offshore soil investigation (by Russian experience)
A.S. Loktev

Piezocone evaluation of undrained strength in soft to firm offshore clays
P.W. Mayne, J. Peuchen & D. Baltoukas

Idealized load composition for determination of cyclic undrained degradation of soils
K. Norén-Cosgriff, H.P. Jostad & C. Madshus

A new piston sampler for a remotely operated drilling system
R.S. Santos, M. Alexander, A. Barwise, A.Walta, E. Solhjell & T. Lunne

Some characteristics of carbonate sediments from NorthWest Shelf,Western Australia
S.S. Sharma & H.A. Joer

Predictive equations of shear wave velocity for Bay of Campeche sand
V.M. Taboada, D.C. Roque, P.N. Barrera, S.D.R. Carrión, J.M.H. Duron & K.C. Gan

Strain ε50 and stiffness ratio (E50/Su) for Gulf of Mexico clays
J.Y.Won, H. Suroor, S. Jang & H. Seo

Suitability of Masing rules for seismic analysis of offshore carbonate sediments
N. Yamamoto, S.S. Sharma & C.T. Erbrich

Simulation and experimental study of soil behaviors under principal stress rotations
Y. Yang, Y. Li, Z.Wang & H.-S. Yu

Strength parameters for suction anchors in a high plasticity Ghana clay
S. Yang, T. Lunne, R. Santos, J. Garnon & M. Mansour

The Maximum-Entropy Meshless method for dynamic and coupled analysis of offshore geotechnical problems
N. Zakrzewski & M. Nazem

Shear wave velocity and shear modulus in offshore clays
L. Zuccarino, D.A. Morandi & M. Sottile

In situ and laboratory testing

Method dependency for determining maximum and minimum dry unit weights of sands
Ø. Blaker, T. Lunne, T. Vestgården, L. Krogh, N.V. Thomsen, J.J.M. Powell & C.F.Wallace

Shear strength of dense to very dense Dogger Bank sand
Ø. Blaker & K.H. Andersen

Assessment of dissipation tests in silty soils with standard and non-standard decay
R. Carroll & M. Long

Stiffness degradation and damping of carbonate and silica sands
J.A.H. Carraro & M.S. Bortolotto

Cyclic laboratory testing of chalk to improve the reliability of piled foundation design
D.L. Coyne, M. Rattley, P. Houlston, I. Alobaidi, A. Benson & C. Russell

Measurement and interpretation of downhole seismic probe data for estimating shear wave velocity in deep-water environments
H.Q. Nguyen, D.J. DeGroot, M. Meidani, M. Vanneste & T. Lunne

The variation of the T-bar bearing capacity factor at shallow depths
J.R.M.S. Oliveira, M.S.S. Almeida, K.I. Rammah, P.C. Trejo & M.C.F. Almeida

Weak fractured rock coring via a seafloor based drilling system – a case study
S. Payor, H.Q. Nguyen, M. Quirk & H. Faizi

Measurement uncertainty of offshore Cone Penetration Tests
J. Peuchen & J. Terwindt

An instrumented sampler and its application for suction caisson design
B.W. Porter

Comparison of shear modulus from SCPT, PS logging & laboratory tests of offshore Myanmar
D. Tami &A.R. Jaapar

Visualizing the failure surface of a laboratory vane shear in soft clay using transparent surrogate soil
J.F.Wallace, C.M. Chini, C.J. Rutherford & J.M. Peschel

A specialized triaxial testing technique for deep-sea pressure core sediments
J. Yoneda, A. Masui & N. Tenma

Numerical investigation of ball penetrometer performance in dense sand overlying uniform clay
M. Zhou, Y. Hu & M.S. Hossain

Rock-steel interface testing and considerations for gravity foundations for tidal energy generators
A.D. Ziogos, M.J. Brown, A. Ivanovic & N. Morgan

Jack-up units

The effects of jack-up installation procedures on spudcan capacity in offshore carbonate sediments
A. Amodio, T.M. Chang, V. Kong & C. Erbrich

A finite element study of boulder interaction with spudcans
H. Curtis & P. Allan

Findings of the ISSMGE jack-up leg penetration prediction event
B.F.J. van Dijk & A.G. Yetginer

Finite element analyses of spudcan – subsea template interaction during jack-up rig installation
H.K. Engin, H.D.V. Khoa, H.P. Jostad & T. Alm

Estimation of spudcan penetration using a probabilistic Eulerian finite element analysis
S. Fallah, K. Gavin & E. Moradabadi

Calculations of leg penetrations of heavy lift jack-up vessels in multi-layered soils
J. Lüking & V. Karge

Effects of consolidation during spudcan installation in carbonate silty clay: A dual approach 1293
R. Ragni, B. Bienen, D.Wang & M.J. Cassidy

Squeezing bearing capacity and effects of increasing strength with depth
M. Ramos da Silva, C.C. Smith & J. Jurko

Stability assessment of A-shaped mudmats of mobile production units
R. Silvano, C. Jaeck, H. Versteele, A. Longuet & D. Bignold

Linear and nonlinear foundation response in dynamic analyses of jack-up structures
K.S. Skau, Ø. Torgersrud, H.P. Jostad, H. Hofstede & S. Hermans

Comparison of coupled and decoupled approaches to spudcan-pile interaction
K.K. Tho, N. Chan & J. Paisley

Sinkage analysis of A-shaped jack-up mudmats using the Coupled Eulerian Lagrangian approach
H. Versteele, C. Jaeck, R. Silvano & D. Bignold

Mariner and Gina Krog jack-up foundation challenges
G. Yetginer, G. Håland & G. Svanø

A novel spudcan design for improving foundation performance
X.Y. Zhang, Y.P. Li, Y. Yang, J.T. Yi, F.H. Lee, P.L. Tan, J.F.Wu & S.Q.Wang

Jack-up spudcan penetration analysis: Review of semi-analytical and numerical methods
Y. Zhang, H.D.V. Khoa, V. Meyer & M.J. Cassidy

Design, risk and reliability

A perspective on selecting design strength: Gulf of Mexico deepwater clay
J.Y. Cheon, D.R. Spikula, A.G. Young, R.B. Gilbert & P. Jeanjean

Reliability-based design optimization of laterally loaded monopile foundations for offshore wind turbines
I. Depina & G. Eiksund

A reliability approach to cable risk assessment
S. Gooding, P. Allan, P. Errington & J. Hunt

Approach for the calibration of the load and resistance factors for axial pile capacity calculations
S. Lacasse, F. Nadim, Z.Q. Liu &Y.J. Choi

Accounting for the spatial variability of soil properties in the reliability-based design of offshore piles
Z. Liu, S. Lacasse, F. Nadim, M. Vanneste & G. Yetginer

Uncertainty-based characterization of piezocone and T-bar data for the Laminaria offshore site
L.J.H. Li, M. Uzielli & M.J. Cassidy

Comparison of DNV and API design codes for design of suction anchors
K. Schroeder & S. Resseguier

A safety concept for penetration analyses of suction caissons in sand
H. Sturm, F. Nadim & A. Page

Author index