Evaluation of long-term extreme response statistics of jack-up platforms

Abstract This paper is concerned with the models appropriate for the dynamic assessment of jack-ups, concentrating particularly on the long-term response due to random ocean waves and on work-hardening plasticity models used for spud-can response. A methodology for scaling of short-term statistics, calculated using a Constrained NewWave technique, is shown in a numerical experiment for an example jack-up and central North Sea location. The difference in long-term extreme response statistics due to various footing assumptions is emphasised. Results for two environmental load conditions are described (one excluding and one including wind and current effects) and the role of sea-state severity in the variation of short-term extreme response statistics is also highlighted.

[1]  Martin S. Williams,et al.  Non-linear dynamic analysis of offshore jack-up units , 1998 .

[2]  J. A. Ewing,et al.  Long Term Wave Statistics , 1993 .

[3]  Martin S. Williams,et al.  Development of non-linear numerical models appropriate for the analysis of jack-up units , 1996 .

[4]  Minoo H. Patel.  Dynamics of Offshore Structures , 1989 .

[5]  Guido Gottardi,et al.  Plastic response of circular footings on sand under general planar loading , 1999 .

[6]  G. Z. Forristall,et al.  Combined Oceanographic Criteria for Deepwater Structures in the Gulf of Mexico , 1991 .

[7]  Paul J. Durning.  Prediction Of Maximum Wave Height From Historical Data , 1971 .

[8]  M J Tucker,et al.  WAVES IN OCEAN ENGINEERING , 2001 .

[9]  Ross Wesley Bell,et al.  The analysis of offshore foundations subjected to combined loading , 1991 .

[10]  Philip Jonathan,et al.  TIME DOMAIN SIMULATION OF JACK-UP DYNAMICS WITH THE EXTREMES OF A GAUSSIAN PROCESS , 1997 .

[11]  Bernt J. Leira,et al.  Foundation reliability of a jack-up platform , 1994 .

[12]  L. Boswell.  Recent Developments in Jack-up Platforms , 1992 .

[13]  Svein Fjeld,et al.  RELIABILITY OF OFFSHORE STRUCTURES , 1978 .

[14]  Mark Cassidy,et al.  Analysis of jack-up units using a Constrained NewWave methodology , 2001 .

[15]  P. S. Tromans,et al.  Response based design conditions in the North Sea: Application of a new method , 1995 .

[16]  Chris Martin.  Physical and numerical modelling of offshore foundations under combined loads , 1994 .

[17]  Paul M. Hagemeijer,et al.  A New Model For The Kinematics Of Large Ocean Waves-Application As a Design Wave , 1991 .

[18]  James Franklin Wilson,et al.  Dynamics of Offshore Structures , 1984 .

[19]  Cong Luan Ngo-Tran.  The analysis of offshore foundations subjected to combined loading , 1996 .

[20]  Mark Cassidy,et al.  On the Modelling of Foundations for Jack-up Units on Sand , 1999 .

[21]  J. C. Heideman,et al.  MODELLING THE NORTH SEA THROUGH THE NORTH EUROPEAN STORM STUDY , 1993 .

[22]  R. Eatock Taylor,et al.  Non-linear analysis of jack-up structures subjected to random waves , 1999 .

[23]  Lance Manuel,et al.  The Influence of Alternative Wave Loading and Support Modeling Assumptions on Jack-Up Rig Response Extremes , 1996 .