Frontiers in Offshore Geotechnics II

Frontiers in Offshore Geotechnics II......Page 2
Table of Contents......Page 6
Preface......Page 14
Committees......Page 16
Reviewers......Page 18
Section 1: Keynotes......Page 20
2.1 The geotechnical maze......Page 22
2.3 Complex geology (Root cause 4)......Page 23
2.4 Development scale (Root Cause 5)......Page 29
2.5 Data acquisition constraints (Root Cause 6)......Page 30
2.6 Structural complexity (Root Cause 7)......Page 32
2.7 Inexperience and uncertainty (Root Cause 8)......Page 34
2.8 Communication of geotechnical risks and costs......Page 35
3.1 Evolving practices......Page 36
3.3 Geotechnical and geohazard (G&G) mitigation strategy......Page 37
3.4 Data acquisition......Page 38
3.5 Ground modelling......Page 40
3.6 Scheme definition – geohazard screening and risk assessment, and scheme layout planning......Page 43
3.7 Engineering......Page 44
3.8 Deliverables......Page 47
4 CONCLUDING REMARKS......Page 48
REFERENCES......Page 49
1 INTRODUCTION......Page 52
2.1.1 Stress history......Page 53
2.1.3 Non-linear stress-strain behaviour......Page 54
2.2 Influence of sample disturbance......Page 55
2.3 Remoulded clay behaviour......Page 56
3.1 Non-hydrostatic pore pressures......Page 57
3.4 Gas exsolution......Page 58
3.6 High salinity......Page 59
3.8 Ice gouging, subsea relict permafrost, and ice loading......Page 60
4 REQUIRED SOIL PARAMETERS FOR DESIGN AND ANALYSIS......Page 61
5 BEST PRACTICE RECOMMENDATIONS FOR GEOTECHNICAL SITE CHARACTERISATION......Page 62
5.3 Vessels and deployment modes......Page 63
5.4.2 In situ tools......Page 64
5.5 Measurement of in situ pore water pressure......Page 65
5.5.2 Piezometers......Page 66
5.6.1 Sampling methods......Page 67
5.6.2 Sample handling and storage......Page 68
5.7.2 Evaluation of sample quality......Page 69
5.7.3 Advanced laboratory test procedures......Page 71
5.8.1 Stress history recommendations......Page 72
6 PRESENT AND FUTURE CHALLENGES......Page 73
REFERENCES......Page 74
1 INTRODUCTION......Page 78
2.2 Scope to 30–40m for foundations or anchors......Page 79
2.3 Scope to 1–2m depth for pipelines or risers......Page 80
3.1 Water content and submerged unit weight......Page 81
3.3 Organic content......Page 82
3.4 Particle size distribution......Page 83
3.5 Mineralogy......Page 84
4.1 Yield stress ratio......Page 85
4.2 Compressibility......Page 86
4.4.1 CPT cone resistance and T-bar profiles......Page 87
4.4.2 Undrained shear strength and sensitivity......Page 88
4.6 Thixotropy......Page 90
4.8 Effective parameters from triaxial testing......Page 91
4.9.2 Rate effects......Page 92
4.10.1 Characterisation of the crust......Page 93
5 DESIGN ISSUES RELATED TO SOIL-PIPELINE INTERACTIONS......Page 94
5.2 Pipeline penetration......Page 95
6 DESIGN ISSUES FROM INSTALLATION EXPERIENCES......Page 96
6.1.2 Reverse end bearing capacity......Page 97
6.1.4 Installation behaviour......Page 98
6.2 Suction piles for riser towers......Page 99
6.3 Driven piles......Page 100
7 CONCLUSIONS......Page 101
REFERENCES......Page 102
1.1 Scope of paper......Page 106
1.2 Pipe-soil interaction processes......Page 107
1.3 Comparison with foundation engineering......Page 108
2.1 Illustrations of soil behaviour near pipelines......Page 109
2.2 Disturbance and recovery: T-bar tests......Page 110
2.3 Disturbance and recovery: vertical rod tests......Page 111
2.4 Drained and undrained soil responses......Page 112
3.1 Pipelaying mechanics......Page 113
3.2 Seabed disturbance during pipelaying......Page 114
3.3 As-laid pipeline survey observations......Page 115
3.4 Solutions for vertical pipe penetration......Page 116
4.1 Theoretical failure envelopes......Page 117
4.2 Failure envelopes as friction factors......Page 118
4.4 Quantifying uncertainty in lateral breakout resistance: Monte Carlo analysis......Page 119
4.5 Large amplitude monotonic lateral response......Page 122
4.6 Large amplitude cyclic lateral response......Page 124
5.1 Effective stress and total stress models......Page 126
5.2 Interface shearing and drainage......Page 127
5.3 Episodic interface shearing and consolidation......Page 128
5.4 Application to axial pipeline resistance......Page 129
6.1 Mechanics of ploughing......Page 130
6.2 Existing ploughing resistance model for sand......Page 131
6.3.1 Static ploughing resistance......Page 132
6.3.2 Dynamic ploughing resistance in sand......Page 133
6.4 Ploughing resistance in clay......Page 134
7.2 Jetting in sands......Page 135
7.3 Jetting in clay......Page 136
REFERENCES......Page 139
1 INTRODUCTION......Page 144
1.2 Lateral load transfer......Page 145
2.1 Introduction......Page 146
2.2.1 Form of t-z curve......Page 147
2.2.3 Variable bias parameter......Page 149
2.2.4 Initial strain softening parameter......Page 150
2.2.6 Shear stress outside gap zone......Page 151
2.4 Scale effects......Page 152
2.4.3 Mesh details for GST simulation......Page 153
2.4.4 GST analysis results......Page 154
2.5 Influence of storm order......Page 155
2.5.1 ‘Actual’ storm load time history......Page 156
2.7 Example analysis......Page 158
3.1 Introduction......Page 159
3.3 Envelope p-y response......Page 161
3.4.2 Second cycle......Page 162
3.4.3 Subsequent cycles......Page 163
3.6 Parameters for cyclic p-y response......Page 164
3.6.1 Inflection point......Page 165
3.7 Description of the pCyCOS program......Page 167
3.8.1 Example 1......Page 168
3.8.2 Example 2......Page 169
4 CONCLUSIONS......Page 172
REFERENCES......Page 173
1 INTRODUCTION......Page 174
2.1 Centrifuge testing......Page 175
2.3 The use of centrifuge outcomes into design......Page 176
2.4 Industry perspective......Page 177
3.2 Disadvantages......Page 178
3.3 Consideration of similitude......Page 179
4.2 Robotic control......Page 180
4.3 Digital imagery......Page 181
4.4 Soil sample reconstitution and characterisation......Page 183
4.5 Models and instrumentation......Page 184
5.1 Provide performance data to calibrate analytical or numerical models......Page 185
5.2 Providing qualitative insights into soil-structure interaction and mechanisms......Page 186
5.3 Validate the structure design for a particular site or a specific design approach......Page 187
5.4 Investigating the feasibility or developing new foundation concept......Page 188
5.5 Developing new design methods......Page 189
5.7 Providing data for assessment of fatigue for conductors and SCRs......Page 191
6.1 Suction caisson technology development......Page 193
6.2 Pipeline-soil interaction......Page 195
6.3 Seabed characterisation......Page 196
6.4 Dynamic lay embedment......Page 197
6.5 Lateral buckling......Page 199
6.6 Integration into design......Page 201
7.1 Hybrid modelling......Page 202
7.2 Enhanced instrumentation......Page 203
REFERENCES......Page 204
2 ACHIEVING APPROPRIATE RISK......Page 208
3 UNDERSTANDING LOADS......Page 209
3.1 Wave-induced mudslides......Page 210
4 MAXIMIZING THE VALUE OF INFORMATION......Page 211
4.1 Design without site-specific soil boring......Page 212
4.2 Updated design using pile driving data......Page 213
4.3 Communication of uncertainty due to lack of information......Page 214
5.1 Mooring system......Page 215
5.2 Jacket pile system......Page 216
6 THE FUTURE......Page 217
REFERENCES......Page 218
Section 2: Geohazards and gas hydrates......Page 220
2 REGIONAL TECTONIC SETTING......Page 222
3.1 Tectonic flexure......Page 223
3.2 Folding and faulting in the Cape Range......Page 224
3.3 Surface faulting and historical earthquakes......Page 225
4 IMPLICATIONS FOR OIL AND GAS DEVELOPMENT......Page 226
1.1 Background......Page 228
3.2 Pockmarks......Page 229
3.4 Faults and seismic hazard......Page 230
3.6 Narrow trough and other bedforms......Page 231
3.8 Salt diapirism......Page 232
REFERENCES......Page 233
2.1 General......Page 234
2.3 Impact of hydrocarbon migration......Page 235
3.3 Suction caissons and piles in soils modified by hydrocarbons......Page 236
3.4 Slope stability......Page 237
REFERENCES......Page 239
2 DEPOSITIONAL ENVIRONMENT AND SHALLOW GAS......Page 240
3 HAZARD MAP AND DELTA CLASSIFICATION......Page 241
4.2 GIS and the hazard map......Page 242
5 CONCLUSIONS......Page 243
REFERENCES......Page 244
2 REVERSE BEHAVIOR OF SILTY SAND AT LOW CONFINING PRESSURES......Page 246
3 COMPRESSIBILITY AS A MEASURE OF LIQUEFACTION POTENTIAL......Page 247
5 EXPERIMENTS TO DETERMINE THE LIQUEFACTION REGION IN STRESS SPACE......Page 248
6 ZONE OF POTENTIAL LIQUEFACTION IN SLOPING GROUND......Page 249
REFERENCES......Page 250
1 INTRODUCTION......Page 252
3 SAMPLE PREPARATION......Page 253
5 RESULTS AND DISCUSSION......Page 254
6 CONCLUSIONS......Page 256
REFERENCES......Page 257
2 THE GROUND MODEL......Page 258
5 BIOSTRATIGARPHIC ANAYSES AND GEOCHRONOLOGICAL TESTING......Page 259
6 DATA INTEGRATION AND CASE STUDIES......Page 260
ACKNOWLEDGEMENTS......Page 262
REFERENCES......Page 263
2.1 Basic features of MH model......Page 264
3.5 Discrete formation of governing equations......Page 265
5 RESULTS OF MH PRODUCTION BY USING DEPRESSURIZATION METHOD......Page 266
REFERENCES......Page 269
Section 3: In situ site characterisation and pore pressure measurement......Page 270
2 CAISSON FOUNDATIONS......Page 272
2.2 Proposed site investigation strategy for fast-track design......Page 273
3.3 New developments......Page 275
3.4 Proposed investigation strategy......Page 276
REFERENCES......Page 277
1 INTRODUCTION......Page 278
4.1 Data interpretation......Page 279
4.3 Monotonic piezoball tests......Page 280
4.4 Cyclic piezoball test......Page 281
REFERENCES......Page 282
2.1 Kaolin clay and clay-bed preparation......Page 284
3 MODEL TEST SETUP AND PROCEDURE......Page 285
4.3 Dynamic penetration resistance......Page 286
5 DISCUSSION......Page 288
REFERENCES......Page 289
2.1 Fundamentals of overpressure behavior......Page 290
2.2 Natural mechanisms and regional overpressure......Page 291
3.1 Penetrometers......Page 292
4 MODELING OVERPRESSURES......Page 293
REFERENCES......Page 294
2.1 GIS capabilities......Page 296
2.3 System architecture......Page 297
3.1 GIS application for analysis......Page 298
4.2.1 Undrained shear strength versus preconsolidation pressure......Page 299
5 CURRENT PROJECT STATUS AND FUTURE PERSPECTIVES......Page 300
REFERENCES......Page 301
1 INTRODUCTION......Page 302
5.1 Miniature full-flow penetrometers and vanes......Page 303
7 ASSESSMENT OF PENETRATION RESISTANCES......Page 304
10 COMPARISON BETWEEN PENETRATION RESISTANCE AND UNDRAINED SHEAR STRENGTH......Page 305
REFERENCES......Page 307
2 EQUIPMENT AND PROCEDURES......Page 308
3.2 Comparison with GPR......Page 309
3.4 Confinement pressure......Page 310
REFERENCES......Page 311
2 PROBLEM DEFINITION......Page 312
3.1 Large deformations......Page 313
3.4 Description of contact interface......Page 314
4.2 Finite element results......Page 315
5 CONCLUSIONS......Page 316
REFERENCES......Page 317
1 INTRODUCTION......Page 318
5.1.1 Advantages......Page 319
7 MARKET SURVEY AND TECHNICAL EVALUATION......Page 320
8 CONCLUSIONS......Page 321
ACKNOWLEDGEMENTS......Page 322
REFERENCES......Page 323
1.2 Interpreting mini T-bar data......Page 324
2.4 Experimental program......Page 325
3.3 Effects of penetration rate and bar roughness......Page 326
5.1 DIC method and surface preparation......Page 327
6 CONCLUSIONS AND RECOMMENDATIONS......Page 328
REFERENCES......Page 329
3 PUSH-IN PIEZOMETERS......Page 330
4 PIEZOMETER INSTALLATION USING A SEABED DRILL......Page 331
6 DISCUSSION OF RESULTS......Page 332
REFERENCES......Page 333
2.2 Initial studies......Page 334
3.3 Drilling, sampling and in-situ testing......Page 335
4.3 Sample preparation......Page 336
5.1.1 Effect of modifications to cutting shoe design......Page 337
5.4 Results of third party verification testing......Page 338
REFERENCES......Page 339
1 INTRODUCTION......Page 340
2.1 Model toroid and pipe......Page 341
2.4 FE analyses of undrained penetration......Page 342
3.2 Cyclic torsional test using toroid......Page 343
REFERENCES......Page 345
1 INTRODUCTION......Page 346
3.1 Comparison for deep water operations......Page 347
3.2 Comparison of performance with water depth in soft soil conditions......Page 348
3.3 Discussion on findings......Page 349
REFERENCE......Page 350
Section 4: Soil characterisation and modelling......Page 352
1 INTRODUCTION......Page 354
3.2 Soils under compression......Page 355
4.1 Undrained triaxial tests......Page 356
4.2.2 One-dimensional compression tests......Page 357
5 CONCLUSIONS......Page 358
REFERENCES......Page 359
2 THE UWA DSS APPARATUS......Page 360
3.1 Theoretical and experimental studies......Page 361
5 THE FINITE ELEMENT MODEL......Page 362
6.2 Shearing phase: Tresca......Page 363
6.3 Shearing phase: EMCC......Page 364
REFERENCES......Page 365
1.2 Context and motivation......Page 366
2 EXPERIMENTAL SETUP, SAMPLE PREPARATION AND PROCEDURES......Page 367
3 CYCLIC TEST RESULTS......Page 368
4 NUMERICAL SIMULATION OF CYCLIC RESPONSE......Page 369
6 CONCLUSIONS......Page 370
REFERENCES......Page 371
2 EQUIPMENTS AND TEST CONDITIONS......Page 372
2.2 Traditional interpretation......Page 373
3.1 Typical test results......Page 374
3.2 Assessment of friction angle......Page 375
3.3 Friction angle comparison; simple shear and triaxial tests......Page 376
REFERENCES......Page 377
3.1 1-D compression response......Page 378
3.2 Monotonic shearing response......Page 379
3.3 Crushing response......Page 380
4.2 Influence of state on crushing......Page 381
4.3 Influence of fines content......Page 382
REFERENCES......Page 383
1.3 The crust: hypothesis-testing......Page 384
2.1 Cam-shear testing......Page 385
3.1 Cam-shear test results......Page 386
3.2 Oedometer test results......Page 387
3.4 Discussion of key observations......Page 388
REFERENCES......Page 389
2.1 Offshore sites......Page 390
2.2 Offshore CPT soundings......Page 391
2.3 General regression trends......Page 392
2.4 Combined onshore and offshore data sets......Page 393
3.2 CPT γt relationships for NC clays......Page 394
REFERENCES......Page 395
1.2 Rate dependence of undrained shear strength......Page 396
3.1 Constant rate of strain DSS......Page 397
3.2 Compression behaviour......Page 399
4.3 Implications for foundation designs......Page 400
REFERENCES......Page 401
2 TESTED MATERIALS AND TESTING PROCEDURES......Page 402
3 TEST RESULTS AND DETERMINATION OF HCA MODEL CONSTANTS......Page 403
6 SUMMARY, CONCLUSIONS AND OUTLOOK......Page 406
REFERENCES......Page 407
1 INTRODUCTION......Page 408
2.2 Flow failure......Page 409
2.4 Plastic strain accumulation......Page 410
2.5 Characterization of cyclic shear strength......Page 411
3 IMPACT OF ROTATION OF PRINCIPAL STRESS AXES......Page 412
REFERENCES......Page 413
Section 5: Shallow foundations......Page 414
2.1 Foundation model......Page 416
2.3 Experimental procedures......Page 417
3.2 Transient (undrained) uplift......Page 418
3.3 Sustained uplift......Page 420
REFERENCES......Page 421
1 INTRODUCTION......Page 422
2.2 Model configuration......Page 423
4.2 Vertical loading-moment......Page 424
4.3 Horizontal load-moment......Page 425
5 THREE DIMENSIONALITY......Page 426
REFERENCES......Page 427
1 INTRODUCTION......Page 428
2.4 Apparatus......Page 429
3.1 Result for s/t =4......Page 430
3.2 Result for s/t=8......Page 431
3.3 Result for different grillage spacings......Page 432
REFERENCES......Page 433
1 INTRODUCTION......Page 434
2 EXPERIMENTAL SET-UP AND MATERIAL PROPERTIES......Page 435
3.1 Spudcan versus skirted footing......Page 436
3.2 Effect of skirt height......Page 437
4 CONCLUSIONS......Page 438
REFERENCES......Page 439
1 INTRODUCTION......Page 440
2 FIELD TEST DATA......Page 441
4 NUMERICAL RESULTS......Page 442
4.1 Installation in homogeneous sand......Page 443
7 CONCLUSION......Page 444
REFERENCES......Page 445
2 TEST PROGRAMME AND GROUND CONDITIONS AT TEST SITE......Page 446
3 FOOTING BEARING CAPACITY......Page 447
4 CREEP SETTLEMENT......Page 449
REFERENCES......Page 450
2 FINITE ELEMENT MODELS......Page 452
3.1 Skirted foundations and rigid solid plugs – kD/sum =0......Page 453
3.2 Skirted foundations and rigid solid plugs – kD/sum =20......Page 454
3.3 Circular skirted foundations – Effect of foundation-soil interface roughness and shear strength heterogeneity......Page 455
REFERENCES......Page 457
2 MECHANISM......Page 458
3 PARAMETRIC STUDY......Page 460
5 SUMMARY AND CONCLUSIONS......Page 461
REFERENCES......Page 462
1.2 Ground conditions......Page 464
2.2 Finite element analysis......Page 465
3 SKIRT INSTALLATION ASSESSMENT......Page 466
3.3 Centrifuge testing......Page 467
4.3 Spudcan impact on foundation design......Page 468
REFERENCES......Page 469
2 SOIL CONDITIONS......Page 470
4.1 Failure description......Page 471
4.2.2 Load path and test equipment......Page 472
5 SOIL IMPROVEMENT......Page 473
REFERENCES......Page 474
Section 6: Piled foundations......Page 476
2 GEOTECHNICAL DATA OF THE SITE......Page 478
4 ANALYSIS METHODOLOGY......Page 479
5 NUMRICAL EXAMPLE......Page 480
6 JUSTIFICATION OF THE ASSUMPTIONS......Page 481
REFERENCES......Page 483
2 STATE OF THE ART......Page 484
3.1 Material and contact modeling......Page 485
4 RESULTS FOR A REFERENCE SYSTEM......Page 486
5 INFLUENCE OF PILE DIAMETER......Page 487
REFERENCES......Page 489
2 SIMULATION OF THE MONOPILE BEHAVIOR UNDER STATIC LOADING......Page 490
3 SIMULATION OF THE MONOPILE BEHAVIOR UNDER CYCLIC LOADING......Page 491
4.1 Test program carried out by LeBlanc et al. (2010)......Page 492
4.2 Simulation with the SDM......Page 493
REFERENCES......Page 495
3 ADVANCED GEOTECHNICAL TESTING......Page 496
4.3 MTD-ICP calculations by the IAT......Page 497
4.8 Summary for pile capacity......Page 498
6 PILE DRIVING TRIALS......Page 499
9 POST-INSTALLATION VERIFICATION......Page 500
REFERENCES......Page 501
2 STRESS AND STRAIN MEASUREMENTS......Page 502
2.1 Stress measurements......Page 503
3.1 Test setup......Page 504
4 CONCLUSIONS......Page 505
REFERENCES......Page 507
1 INTRODUCTION......Page 508
2.2 New formulation......Page 509
3 VALIDATION OF BASIL SPRINGS......Page 510
4.2 External soil springs......Page 511
4.5 Analysis results......Page 512
REFERENCES......Page 513
1 INTRODUCTION......Page 514
3.2 Field-specific......Page 515
5.2 Geotechnical SI......Page 516
6.3 Static pile capacities......Page 517
6.6 Risk reduction......Page 518
REFERENCES......Page 519
2 SITE CHARACTERISTICS......Page 520
3 PILE INFORMATION......Page 521
4 DYNAMIC TEST RESULTS......Page 522
5.2 Shaft set-up estimate from SPT N-value......Page 523
APPENDIX A......Page 525
2.1 Geometry and constitutive model......Page 526
2.3 Pile model......Page 527
3.1 Test 1 at Lm/Ls =400/300 and Q=0N......Page 528
3.3 Summary of results and discussion......Page 529
4 EFFECT OF LM/LS RATIO......Page 530
REFERENCES......Page 531
3 CONSTITUTIVE BEHAVIOUR......Page 532
4 ENGINEERING PROPERTIES......Page 533
7 CYCLIC TEST RESULTS......Page 534
REFERENCE......Page 537
3 GROUND CONDITIONS......Page 538
5 PILE TEST RESULTS......Page 540
6 PREDICTED AND MEASURED CAPACITIES......Page 541
REFERENCES......Page 542
2.1 Assumed stratigraphy......Page 544
2.2.3 Analysis sequence......Page 545
3.1.3 Analysis parameters......Page 546
4.2.2 Structural period......Page 547
REFERENCES......Page 548
1 INTRODUCTION......Page 550
3 MODEL DESCRIPTION......Page 551
4 CASE STUDY......Page 552
6 CONCLUSIONS......Page 553
ACKNOWLEDGMENTS......Page 554
REFERENCES......Page 555
2.1 Centrifuge modelling......Page 556
2.3 Model materials......Page 557
3 RESULTS OF THE CENTRIFUGE TEST......Page 558
4.2 Soil resistance......Page 559
4.4 Plugging......Page 560
REFERENCES......Page 561
1 INTRODUCTION......Page 562
2 STRAIN WEDGE MODEL......Page 563
4 LATERAL ANALYSIS OF PILES (LAP) PROGRAM......Page 564
5 COMPARISON AND DISCUSION......Page 565
6 CONCLUSION......Page 566
REFERENCES......Page 567
2 PROJECT DESCRIPTION......Page 568
4.3 Design UCS profile......Page 569
6 STATIC LOAD TESTS......Page 570
8 DRIVEABILITY ANALYSIS......Page 572
REFERENCES......Page 573
2.2 Soil parameters......Page 574
4.1 General equation......Page 575
4.3.2 Pile length......Page 576
6 LIMITATIONS......Page 577
REFERENCES......Page 578
Section 7: Foundations for renewable energy......Page 580
2 DESIGN METHODS......Page 582
3 DATABASE EVALUATION......Page 584
4 PARAMETRIC STUDY......Page 585
5 CONCLUSIONS......Page 586
REFERENCES......Page 587
2 EQUIPMENT......Page 588
3.1 Sand – Skirt tip injection and steering......Page 589
4.1 Clay overlying sand......Page 590
4.2.2 Inclined clay substratum......Page 591
5 EFFECT OF GROUTING......Page 592
REFERENCES......Page 593
1.2 Background......Page 594
2.2 Soil models used in the analyses......Page 595
4.2 SPLICE analysis......Page 596
5.2 FLAC analysis results......Page 597
6 SUMMARY AND CONCLUSIONS......Page 598
REFERENCES......Page 599
2.2 Scale effects......Page 600
3 EXPERIMENTS......Page 601
3.1 Monotonic tests......Page 602
3.2 Cyclic tests......Page 603
4 CONCLUSIONS......Page 604
REFERENCES......Page 605
2 SUBSURFACE CONDITIONS......Page 606
2.2 Soil properties......Page 607
3.1 Bearing capacity and sliding......Page 608
4 DESIGN AT LOCATIONS WITH LAYERED SOIL......Page 609
4.2 Three-dimensional modelling......Page 610
REFERENCES......Page 611
1 INTRODUCTION......Page 612
2.1 Wind......Page 613
3 ENVIRONMENTAL LOADING......Page 614
4.2 Soil behavior......Page 615
4.3 Site investigation......Page 616
REFERENCES......Page 617
3 GREAT LAKES BATHYMETRY......Page 618
6.1 General conditions......Page 620
6.4 Ice loading......Page 621
7.3 Tension cone failure......Page 622
REFERENCES......Page 623
1 INTRODUCTION......Page 624
2 MODEL PREPARATION AND TESTING PROCEDURE......Page 625
3.1 Load-displacement response......Page 626
4 FINITE ELEMENT RESULTS......Page 627
REFERENCES......Page 629
2.2 Discussion of generic design input......Page 630
3.2 Cyclic pore pressure accumulation......Page 631
3.3 Derivation of sand parameters for the ‘undrained’ model......Page 632
4.2 Undrained analyses......Page 633
5.1 Drained analyses......Page 634
REFERENCES......Page 635
1 INTRODUCTION......Page 636
3 TEST SETUP......Page 637
3.4 Soil samples and CPT’s......Page 638
4.1 Time scale of backfill......Page 639
4.2 Relative density of backfilled sand......Page 640
REFERENCES......Page 641
1 INTRODUCTION......Page 642
2.2 Centrifuge test procedure......Page 643
3.1 Vertical loading......Page 644
3.3 Bending moments......Page 645
REFERENCES......Page 646
2 STATISTICAL AND GEOSTATISTICAL VARIABILITY ACROSS THE SITE......Page 648
3 GEOSTATISTICAL VARIABILITY MODELS AND GEOSTATISTICAL SIMULATION......Page 649
4 RELIABILITY CALCULATION......Page 650
5 COST-RELIABILITY MODEL......Page 651
REFERENCES......Page 652
2 LITERATURE REVIEW......Page 654
4 CALIBRATION OF THE HCA MODEL FOR A FINE SAND......Page 655
5 FE CALCULATIONS......Page 657
6 SUMMARY, CONCLUSIONS AND OUTLOOK......Page 658
REFERENCES......Page 659
1.2 Self-healing effect......Page 660
2.1 Loading history......Page 661
2.2 Test setup......Page 662
3.1 Reference example......Page 663
3.2 Amplitude variations......Page 664
REFERENCES......Page 665
1 INTRODUCTION......Page 666
2.1 Soil tank and soil preparation......Page 667
2.2 Test setup......Page 668
3.3 Soil-structure interaction of caisson......Page 669
REFERENCES......Page 671
Section 8: Jack-up units......Page 672
2.2 Combined VH loading and yield surface......Page 674
3.3 Comparison of results......Page 675
4.1 Vertical bearing capacity......Page 676
5.2 Pure vertical loading......Page 677
5.3 VH yield surface......Page 678
REFERENCES......Page 679
1 INTRODUCTION......Page 680
2.2 Refinement within a data base......Page 681
3.3 Information from CoV and bias......Page 682
3.4 Refinement within the InSafeJIP data base......Page 683
3.5 Ideal way forward......Page 684
REFERENCES......Page 685
1.1 Evolution of jack-up rig operations and in situ seabed profiles......Page 686
2.1 Experimental program......Page 687
3.1 NC clay with interbedded stiff layer......Page 688
3.2 T-bar to spudcan resistance......Page 689
3.4 OC clay with interbedded stiff layers......Page 690
REFERENCES......Page 691
1 INTRODUCTION......Page 692
2.1 Overall method......Page 693
2.2.2 Soil properties......Page 694
2.2.6 Calibration......Page 695
3 COMPARISONS WITH DATA......Page 696
REFERENCES......Page 697
3.1 Fundamental understanding......Page 698
4 WAVE-INDUCED PULLOUT FORCE......Page 699
6.1 Discussion......Page 700
7.2 Alternative spudcan mitigation device......Page 702
REFERENCES......Page 703
2.1 Coupled Eulerian-Lagrangian Method......Page 704
2.4 Constitutive models......Page 705
3.2 Penetration into uniform sand......Page 706
4.1 Numerical results......Page 707
4.2 Comparison with conventional analyses......Page 708
REFERENCES......Page 709
2.1 Footings......Page 710
2.5 Load paths......Page 711
3.1.1 Uniaxial bearing capacity of the spudcan......Page 712
3.2.2 Comparison with circular plate footings......Page 713
3.3.2 Curve fitting......Page 714
REFERENCES......Page 715
Section 9: Anchoring systems......Page 716
2 ANCHOR CHAIN IN AN OBLIQUE PLANE......Page 718
3 COMPUTATION SEQUENCE......Page 720
4 EXAMPLE ANALYSIS......Page 721
REFERENCES......Page 722
1 INTRODUCTION......Page 724
2.3 Sample preparation and soil properties......Page 725
3.1 Test programme summary......Page 726
3.3 Anchor capacity......Page 727
4 CONCLUSIONS......Page 728
REFERENCES......Page 729
2.1 Dynamic centrifuge modelling......Page 730
2.3 Model containment and loading system......Page 731
3.1 Permanent displacements......Page 732
3.2 Acceleration response......Page 733
4.2 Plastic displacement......Page 734
REFERENCES......Page 735
2 SEPLA DEPLOYMENT AND KEYING SEQUENCE......Page 736
5 TEST SEPLA GEOMETRY......Page 737
7 ANALYSIS OF TEST RESULTS......Page 738
9 VANE SHEAR ANALOG MODEL......Page 740
ACKNOWLEDGEMENTS......Page 741
2.1 Soil conditions......Page 742
2.2 Installation behaviour......Page 743
3.1 Set-up database......Page 744
3.2 Calculated average interface friction factor......Page 745
REFERENCES......Page 746
2.1 Soil characteristics......Page 748
3.1 Penetration phase......Page 749
4.1 Clay parameters......Page 750
4.3 Pull-out capacity......Page 751
REFERENCES......Page 753
2.1 FEM characteristics and parameters simulated......Page 754
2.3 2D and AXI FEM results......Page 755
3 LABORATORY ANCHOR TESTS......Page 757
4 COMPARISONS WITH LITERATURE RESULTS......Page 758
REFERENCES......Page 759
2.2 Generic mesh design......Page 760
3 MH ELLIPSES AT V=0......Page 761
4 V-HMAX ELLIPSOIDS......Page 762
5 MH ELLIPSES AT V=0......Page 763
9 CONCLUSIONS......Page 764
REFERENCES......Page 765
2 N-R ANCHOR EMBEDMENT MODEL......Page 766
4 INCLUSION OF SOIL SENSITIVITY IN N-R MODEL......Page 767
5.1 Soil consolidation effects......Page 768
5.2 Assessment of average degree of consolidation......Page 769
5.3 Cyclic loading effects......Page 770
REFERENCES......Page 771
1.3 VHM resistance envelopes......Page 772
2.2 Material properties......Page 773
3 PLAXIS RESULTS......Page 774
4 COMPARISON WITH LIMIT EQUILIBRIUM MODEL......Page 775
7 NOTATION......Page 776
REFERENCES......Page 777
2 GEOMETRY......Page 778
4 MATERIAL MODEL......Page 779
6.1 Failure mechanisms......Page 780
6.2 Failure envelope comparison......Page 781
8 APPENDIX......Page 782
REFERENCES......Page 783
1 INTRODUCTION......Page 784
2.1 Cyclic loading rig and testing procedure......Page 785
2.2 Test program......Page 786
3.1 Cyclic accumulated deformation......Page 787
3.3 Unloading stiffness......Page 788
REFERENCES......Page 789
Section 10: Pipelines and risers......Page 790
2.1 The SIGMA/AEEPECD software......Page 792
2.2 Soil material properties......Page 793
3.2 Resultant force versus displacement curves......Page 794
3.3 Comparison with ALA (2005)......Page 795
4 CONCLUSIONS......Page 796
REFERENCES......Page 797
2 DESIGN CHALLENGES......Page 798
3.2 Project specific testing and interpretation......Page 799
4 ‘HEAVY’ PIPE RESPONSE......Page 800
6.1 Walking response of long pipelines......Page 801
REFERENCES......Page 802
2.1 Methodology......Page 804
2.5 Comparison with centrifuge result......Page 805
4.2 Effects of unit weight variation......Page 806
5 SUMMARY AND CONCLUSIONS......Page 808
REFERENCES......Page 809
2.1 General......Page 810
2.4 Implementation of traditional friction factor approach......Page 811
2.7 Comparison of pipeline dynamic lateral stability response to Coulomb, Verley and Sotberg (1992) and UWAPIPE models......Page 812
2.8 Implementation of geotechnical techniques – modelling of pipelay induced embedment and its effect on lateral resistance......Page 813
3 SUMMARY AND CONCLUSIONS......Page 814
REFERENCES......Page 815
1 INTRODUCTION......Page 816
2.1.3 Constitutive model for soils and the material properties......Page 817
3 NUMERICAL RESULTS AND ANALYSES......Page 818
3.1 Effects of soil internal friction angle......Page 819
3.2 Effects of pipe-soil friction coefficient......Page 820
REFERENCES......Page 821
2.2 Soil properties......Page 822
3.2 Cyclic penetration......Page 823
3.3 Normalized secant stiffness......Page 824
3.5 Comparison with earlier work......Page 826
REFERENCES......Page 827
3 NEAR SHORE APPROACH......Page 828
6 LOCAL CONSENT......Page 829
9.2 Detailed design......Page 830
11 DISCRETE ROCK BERM IMPLICATIONS......Page 831
PREFERENCES, SYMBOLS AND UNITS......Page 832
REFERENCES......Page 833
1 INTRODUCTIONS......Page 834
2.3 Data recording......Page 835
3.1 Influence of diameter to the soil resistance......Page 836
3.2 Influence of burial depth to soil resistance......Page 837
4 CONCLUSIONS......Page 838
REFERENCES......Page 839
1.1 Background......Page 840
1.2 Scope of study and problem definition......Page 841
3.1 Linear increasing shear strength......Page 842
3.2 Shear strength crusts......Page 844
REFERENCES......Page 845
2 CYCLIC LATERAL PIPELINE-SEABED INTERACTION ANALYSIS......Page 846
3 NUMERICAL RESULTS......Page 848
REFERENCES......Page 851
1 INTRODUCTION......Page 852
2.2 Normalised maximum stiffness, Kmax......Page 853
3 CASE STUDY......Page 854
4.1 Fatigue results for LS1......Page 855
4.3 Equivalent linear stiffness......Page 856
REFERENCES......Page 857
1 INTRODUCTION......Page 858
3 RESEARCH OBJECTIVES......Page 859
5 RESULTS AND DISCUSSION......Page 860
ACKNOWLEDGEMENT......Page 862
REFERENCES......Page 863
2 THEORETICAL ANALYSES......Page 864
2.2 Static pipe lay and placement on linear seabed......Page 865
3 FIELD STUDIES......Page 866
4.1 Static pipe lay on linear seabed......Page 867
4.3 Dynamic pipe lay on non-linear seabed......Page 868
REFERENCES......Page 869
2 DESCRIPTION OF THE SMARTPIPE®......Page 870
4 EXCESS PORE PRESSURE DISSIPATION......Page 871
5.2 Interpretation of effective stresses......Page 872
5.3 Total and effective stress failure criteria......Page 873
5.4 Mobilisation: A function of distance or time?......Page 874
REFERENCES......Page 875
Section 11: Trenching, ploughing, excavation and burial......Page 876
1.1 Ice gouging......Page 878
2.1 Test samples......Page 879
3.2 Effect of geometry and weight on penetration and drag force......Page 880
3.3 Influence of the curvature of front edge of the object......Page 882
REFERENCES......Page 883
2.1 Introduction......Page 884
3.2 The forecutter’s influence on ploughing depth......Page 885
3.3 The forecutter’s influence on tow force in dry sand......Page 886
3.5 The effect of a forecutter on rate effects......Page 887
5 CONCLUSIONS......Page 888
REFERENCES......Page 889
2 CHARACTERISTICS OF SUBMERGED WATER JETS......Page 890
2.2 Correlation with test observations......Page 891
2.3 Dis-aggregation in clay soils......Page 892
2.5 Hydro-fracture and fluidization behavior......Page 893
REFERENCES......Page 894
2.1 Introduction......Page 896
3.2 Example problem......Page 897
3.3 Effect of plough weight......Page 898
3.6 Change in share blade angle......Page 899
4 RESULTS: RATE EFFECTS......Page 900
REFERENCES......Page 901
2.1.2 Experimental research......Page 902
2.2 Centrifuge test on interaction chain–rockfill......Page 903
2.4 Anchor dragging test with SEA-anchor......Page 904
3.2 Improved chain modelling......Page 905
3.6 Extension to 3D and discrete element models......Page 906
REFERENCES......Page 907
3.1 Model basis......Page 908
3.2.2 Experimental results......Page 909
3.3.2 Governing equations......Page 910
3.4 Comparison of model with experimental data......Page 911
5 CASE STUDY......Page 912
REFERENCES......Page 913
Section 12: Design and risk......Page 914
2 MODELS FOR ANALYSIS......Page 916
3 WELL CONDUCTORS......Page 917
4 STEEL YIELD STRESS......Page 918
7 SYSTEM REDUNDANCY......Page 919
REFERENCES......Page 921
2.1 API 21st edition (2000)......Page 922
3.3 The RP 2GEO approach for pile design......Page 923
3.6 Example of pile capacity calculations......Page 926
REFERENCES......Page 927
2 OFFSHORE DESIGN GUIDELINES......Page 928
3.3 Recurrence relationships......Page 929
4 SEISMIC HAZARD RESULTS......Page 930
5.2.1 Sensitivity assessment considering the response period hazard curve......Page 931
5.2.2 Sensitivity assessment considering the slope aR of the hazard curve......Page 932
REFERENCES......Page 933
2 TERMINOLOGY......Page 934
4 PIPELINES EXAMPLE......Page 935
4.1 Improved routing......Page 936
5 WIND FARMS EXAMPLE......Page 937
REFERENCES......Page 938