1.0 INTRODUCTION 1-1.......................................................................................................................1.1 OVERVIEW 1-1.........................................................................................................................1.2 PROGRAM FEATURES 1-1......................................................................................................1.3 MEMBER LOADS CREATED BY SEASTATE 1-3................................................................

2.0 GENERAL SEASTATE DATA 2-1.................................................................................................2.1 SEASTATE OPTIONS 2-1.........................................................................................................

2.1.1 Physical Parameters 2-1.....................................................................................................2.1.2 Analysis Function 2-1........................................................................................................2.1.3 Output Reports 2-1............................................................................................................2.1.4 Hydrostatic Check 2-2.......................................................................................................2.1.5 Miscellaneous 2-2..............................................................................................................

2.2 USING A SEPARATE SEASTATE INPUT FILE 2-2..............................................................2.2.1 Location of Loading 2-2....................................................................................................2.2.2 Selecting Load Cases 2-2...................................................................................................2.2.3 Factoring Load Cases 2-3..................................................................................................2.2.4 Allowable Stress/Material Factor 2-4................................................................................2.2.5 Load Combinations 2-4.....................................................................................................

2.3 PROPERTY OVERRIDES 2-4...................................................................................................2.3.1 Overriding Beam Element Properties 2-4..........................................................................

2.3.1.1 Marine Growth and Reynolds Number 2-5............................................................2.3.1.2 Flood Condition 2-5.................................................................................................2.3.1.3 Weight and Buoyancy 2-5........................................................................................2.3.1.4 Dimensions for Force 2-6.........................................................................................2.3.1.5 Drag and Mass Coefficients 2-6...............................................................................

2.3.2 Overriding Plate Element Properties 2-6...........................................................................2.3.2.1 Weight 2-7................................................................................................................

2.4 WIND AREAS 2-7......................................................................................................................2.5 WIND SHIELD ZONES 2-8.......................................................................................................2.6 SUBMERGED BODIES 2-9......................................................................................................2.7 NON-STRUCTURAL ELEMENTS 2-10....................................................................................

2.7.1 Dummy Sub-Structures 2-10...............................................................................................2.7.2 Appurtenance Structures 2-11.............................................................................................2.7.3 Alternate Method 2-11.........................................................................................................

2.8 ELEMENT LOAD REPORTS 2-11.............................................................................................2.9 STRUCTURAL LOADING 2-12.................................................................................................

2.9.1 Structural Masses 2-12........................................................................................................2.9.1.1 Inertial Weight 2-12...................................................................................................2.9.1.2 Weight Vertical Location 2-13...................................................................................2.9.1.3 Surface Weight 2-13...................................................................................................2.9.1.4 Structural Weight Footprint 2-14...............................................................................2.9.1.5 Joint Weight 2-15.......................................................................................................2.9.1.6 Member Weight 2-16.................................................................................................2.9.1.7 Non-Structural Weight 2-17.......................................................................................2.9.1.8 Weight Combinations 2-17........................................................................................2.9.1.9 Dynamic Mass Selection 2-18....................................................................................

2.9.2 Direct Load Determination 2-18..........................................................................................2.9.2.1 Weight Inclusion In Loading 2-18.............................................................................2.9.2.2 Inertia Load Center Location 2-19.............................................................................2.9.2.3 Applied Structure Acceleration 2-19..........................................................................2.9.2.4 Response Amplitude Operators 2-20.........................................................................2.9.2.5 Space Forces and Moments 2-21...............................................................................2.9.2.6 Moving Load 2-21......................................................................................................

3.0 HYDRO STATIC/DYNAMIC DATA 3-1........................................................................................3.1 FLOOD CONDITION 3-1..........................................................................................................

3.1.1 Default Flood Condition 3-1..............................................................................................3.1.2 Specifying Flood Condition in the Model 3-1...................................................................3.1.3 Overriding Flood Condition 3-1........................................................................................

3.2 MARINE GROWTH 3-2............................................................................................................3.2.1 Defining Marine Growth 3-2.............................................................................................3.2.2 Applying Marine Growth to a Member 3-2.......................................................................

3.3 DRAG AND MASS COEFFICIENTS 3-3.................................................................................3.3.1 Defining Default Coefficients 3-3.....................................................................................3.3.2 Reynolds Number Dependent Cd 3-4..............................................................................3.3.3 Overriding Coefficients 3-4...............................................................................................

3.4 HYDRODYNAMIC MODELING 3-5.......................................................................................

4.0 CREATING ENVIRONMENTAL LOADS 4-1...............................................................................4.1 MEMBER LOAD AXIS 4-1.......................................................................................................4.2 ENVIRONMENTAL LOAD FACTORS 4-1.............................................................................4.3 WAVE LOAD 4-1......................................................................................................................

4.3.1 Wave Theory 4-1...............................................................................................................4.3.1.1 User Defined Waves 4-2..........................................................................................

4.3.2 Wave Characteristics 4-3...................................................................................................4.3.3 Critical Crest Position 4-3.................................................................................................4.3.4 Overriding Water Depth and Mudline Elevation 4-4........................................................4.3.5 Wave Kinematics or Spreading Factor 4-4........................................................................4.3.6 Member Distributed Load Segments 4-4...........................................................................4.3.7 Wave Output Print Option 4-5...........................................................................................

4.4 CURRENT LOAD 4-5................................................................................................................4.4.1 Current Velocity Profile 4-6..............................................................................................4.4.2 Current Profile Stretching/Compressing 4-6.....................................................................4.4.3 Current Blockage Factor 4-7.............................................................................................4.4.4 Apparent Wave Period 4-7................................................................................................4.4.5 Overriding Mudline Elevation 4-8.....................................................................................4.4.6 Minimum In-line Current 4-8............................................................................................

4.5 GRAVITY AND BUOYANCY LOAD 4-8...............................................................................4.5.1 Overriding Buoyancy Parameters 4-9................................................................................

4.6 WIND LOAD 4-10........................................................................................................................4.6.1 Wind Characteristics 4-10...................................................................................................4.6.2 Wind Height Variation 4-11................................................................................................4.6.3 Overriding Water Depth 4-12..............................................................................................

4.6.4 Loading Wind Areas 4-12...................................................................................................4.7 SUBMERGED BODY DRAG LOAD 4-12.................................................................................4.8 MUD FLOW LOAD 4-13.............................................................................................................4.9 REPEATING A LOAD CASE 4-14.............................................................................................4.10 API RP2A-WSD 20TH EDITION CONSIDERATIONS 4-14..................................................

5.0 GENERATING TRANSFER FUNCTION LOADS 5-1..................................................................5.1 SPECIFYING TRANSFER FUNCTION WAVE DATA 5-1....................................................

5.1.1 Critical Wave Crest Positions 5-1......................................................................................5.1.1.1 Dynamic Analysis 5-2..............................................................................................5.1.1.2 Static Analysis 5-2...................................................................................................

5.1.2 Creating Global Transfer Function Plots 5-2.....................................................................5.1.2.1 Dynamic Analysis 5-2..............................................................................................5.1.2.2 Static Analysis 5-3...................................................................................................

6.0 SEASTATE INPUT FILE 6-1...........................................................................................................6.1 INPUT FILE SETUP 6-1............................................................................................................6.2 USER DEFINED WAVE INPUT 6-143........................................................................................

7.0 COMMENTARY 7-1........................................................................................................................7.1 WAVE GENERATION 7-1........................................................................................................7.2 AIRY WAVE THEORY 7-3.......................................................................................................7.3 STOKES WAVE THEORY 7-4................................................................................................7.4 STREAM FUNCTION THEORY 7-4........................................................................................7.5 CNOIDAL AND SOLITARY WAVE THEORIES 7-6.............................................................7.6 MEMBER FORCES FROM WAVES AND CURRENT 7-6....................................................7.7 BUOYANCY 7-9........................................................................................................................7.8 FORCES DUE TO MUD FLOW 7-11.........................................................................................7.9 API RP2A-WSD 20TH EDITION WAVE DETERMINATION 7-12.........................................

7.9.1 Apparent Wave Period 7-12................................................................................................7.9.2 Current Blockage 7-12.........................................................................................................7.9.3 Current Profile Stretching or Compressing 7-12.................................................................7.9.4 Coefficient of Drag and Mass 7-13......................................................................................

8.0 SAMPLE PROBLEMS 8-1...............................................................................................................8.1 SAMPLE PROBLEM 1 8-2........................................................................................................8.2 SAMPLE PROBLEM 2 8-11........................................................................................................8.3 SAMPLE PROBLEM 3 8-19........................................................................................................8.4 SAMPLE PROBLEM 4 8-21........................................................................................................

! "

! "

#

$