q 2007 by Taylor & Francis Group, LLC q 2007 by Taylor & Francis Group, LLC To the great pioneers in Marine and Offshore Construction who were undeterred by violent storms and massive ice. q 2007 by Taylor & Francis Group, LLC Preface This third editon has been intensively augmented and revised to include the latest developments in this rapidly expanding field. The intensified search for oil and gas, the catastrophic flooding of coastal regions and the demands for transportation, bridges, sub- merged tunnels and waterways have led to the continuing innovation of new technology which is nowavailable for use on more conventional projects as well as those at the frontiers. This text is intended as a guide and reference for practicing engineers and constructors for use in the marine environment. It is also intended as a text for graduate engineering students interested in this highly challenging endeavour. q 2007 by Taylor & Francis Group, LLC Acknowledgments I wish to acknowledge the help of many members of our company, Ben C. Gerwick, Inc. making available information on the current construction of marine and offshore projects, also the willing responses to my queries from other sources in the industry. I would like to thank my administrative assistant, Michelle Yu, for her word-processing of the manuscript. q 2007 by Taylor & Francis Group, LLC Author Ben C. Gerwick, Jr. is the author of Construction of Prestressed Concrete, first, second, and third editions, and the first and second editions of Construction of Marine and Offshore Structures. He was born in Berkeley, California, in 1919. He received his B.S. in civil engineering from the University of California at Berkeley in 1940. He joined the U.S. Navy the same year and served until 1946. He was assigned as commanding officer of the USS Scania (AK 40) in 1945. He has worked in marine and offshore construction, or taught about it, for most of the time since his discharge from the navy. He worked in Marine Construction from 1946 to 1967 and from 1967 to 1971 in Offshore Construction, ending as President of Ben C. Gerwick, Inc., and Manager of Offshore Construction for Santa Fe International. From 1971 to 1989, he served as Professor of Civil Engineering at the University of California, Berkeley. He is a member of the National Academy of Engineering, the National Academy of Construction, and an honorary member of the American Society of Civil Engineers, which awarded him their Outstanding Engineering Lifetime Achievement Award in 2002. He has been named a fellow of the International Association of Structural and Bridge Engineers and has served as president of the International Federation of Prestressing. He was awarded the Berkeley Fellow Medal in 1989. q 2007 by Taylor & Francis Group, LLC Contents Introduction 0.1 General 1 0.2 Geography 3 0.3 Ecological Environment 4 0.4 Legal Jurisdiction 4 0.5 Offshore Construction Relationships and Sequences 5 0.6 Typical Marine Structures and Contracts 8 0.7 Interaction of Design and Construction 9 Chapter 1 Physical Environmental Aspects of Marine and Offshore Construction 1.1 General 15 1.2 Distances and Depths 15 1.3 Hydrostatic Pressure and Buoyancy 16 1.4 Temperature 17 1.5 Seawater and Sea–Air Interface Chemistry 18 1.5.1 Marine Organisms 18 1.6 Currents 20 1.7 Waves and Swells 25 1.8 Winds and Storms 31 1.9 Tides and Storm Surges 34 1.10 Rain, Snow, Fog, Spray, Atmospheric Icing, and Lightning 36 1.11 Sea Ice and Icebergs 37 1.12 Seismicity, Seaquakes, and Tsunamis 42 1.13 Floods 43 1.14 Scour 44 1.15 Siltation and Bed Loads 44 1.16 Sabotage and Terrorism 45 1.17 Ship Traffic 45 1.18 Fire and Smoke 46 1.19 Accidental Events 46 1.20 Global Warming 47 Chapter 2 Geotechnical Aspects: Seafloor and Marine Soils 2.1 General 49 2.2 Dense Sands 52 2.3 Liquefaction of Soils 52 2.4 Calcareous Sands 53 2.5 Glacial Till and Boulders on Seafloor 53 2.6 Overconsolidated Silts 54 2.7 Subsea Permafrost and Clathrates 55 q 2007 by Taylor & Francis Group, LLC 2.8 Weak Arctic Silts and Clays 55 2.9 Ice Scour and Pingos 56 2.10 Methane Gas 56 2.11 Muds and Clays 56 2.11.1 Underwater Slopes in Clays 57 2.11.2 Pile Driving “Set-Up” 58 2.11.3 Short-Term Bearing Strength 58 2.11.4 Dredging 58 2.11.5 Sampling 58 2.11.6 Penetration 59 2.11.7 Consolidation of Clays; Improvement in Strength 59 2.12 Coral and Similar Biogenic Soils; Cemented Soils, Cap Rock 59 2.13 Unconsolidated Sands 60 2.14 Underwater Sand Dunes (“Megadunes”) 62 2.15 Bedrock Outcrops 62 2.16 Cobbles 63 2.17 Deep Gravel Deposits 64 2.18 Seafloor Oozes 64 2.19 Seafloor Instability and Slumping; Turbidity Currents 64 2.20 Scour and Erosion 65 2.21 Concluding Remarks 66 Chapter 3 Ecological and Societal Impacts of Marine Construction 3.1 General 69 3.2 Oil and Petroleum Products 69 3.3 Toxic Chemicals 70 3.4 Contaminated Soils 71 3.5 Construction Wastes 71 3.6 Turbidity 71 3.7 Sediment Transport, Scour, and Erosion 72 3.8 Air Pollution 72 3.9 Marine Life: Mammals and Birds, Fish, and Other Biota 73 3.10 Aquifers 74 3.11 Noise 74 3.12 Highway, Rail, Barge, and Air Traffic 75 3.13 Protection of Existing Structures 75 3.14 Liquefaction 77 3.15 Safety of the Public and Third-Party Vessels 77 3.16 Archaeological Concerns 78 Chapter 4 Materials and Fabrication for Marine Structures 4.1 General 79 4.2 Steel Structures for the Marine Environment 79 4.2.1 Steel Materials 80 4.2.2 Fabrication and Welding 80 4.2.3 Erection of Structural Steel 85 4.2.4 Coatings and Corrosion Protection of Steel Structures 88 4.2.5 High Performance Steels 91 4.3 Structural Concrete 91 q 2007 by Taylor & Francis Group, LLC 4.3.1 General 91 4.3.2 Concrete Mixes and Properties 91 4.3.2.1 High Performance Concrete— “Flowing Concrete” 95 4.3.2.2 Structural Low-Density Concrete 96 4.3.2.3 Ultra-High Performance Concrete (UHPC) 97 4.3.3 Conveyance and Placement of Concrete 97 4.3.4 Curing 98 4.3.5 Steel Reinforcement 98 4.3.6 Prestressing Tendons and Accessories 102 4.3.7 Embedments 105 4.3.8 Coatings for Marine Concrete 106 4.3.9 Construction Joints 106 4.3.10 Forming and Support 107 4.3.11 Tolerances 108 4.4 Hybrid Steel–Concrete Structures 108 4.4.1 Hybrid Structures 109 4.4.2 Composite Construction 109 4.5 Plastics and Synthetic Materials, Composites 111 4.6 Titanium 113 4.7 Rock, Sand, and Asphaltic-Bituminous Materials 114 Chapter 5 Marine and Offshore Construction Equipment 5.1 General 117 5.2 Basic Motions in a Seaway 118 5.3 Buoyancy, Draft, and Freeboard 120 5.4 Stability 121 5.5 Damage Control 124 5.6 Barges 126 5.7 Crane Barges 130 5.8 Offshore Derrick Barges (Fully Revolving) 134 5.9 Semisubmersible Barges 137 5.10 Jack-Up Construction Barges 140 5.11 Launch Barges 144 5.12 Catamaran Barges 146 5.13 Dredges 147 5.14 Pipe-Laying Barges 152 5.15 Supply Boats 155 5.16 Anchor-Handling Boats 156 5.17 Towboats 156 5.18 Drilling Vessels 157 5.19 Crew Boats 158 5.20 Floating Concrete Plant 158 5.21 Tower Cranes 159 5.22 Specialized Equipment 160 Chapter 6 Marine Operations 6.1 Towing 161 6.2 Moorings and Anchors 169 6.2.1 Mooring Lines 169 q 2007 by Taylor & Francis Group, LLC 6.2.2 Anchors 170 6.2.2.1 Drag Anchors 170 6.2.2.2 Pile Anchors 174 6.2.2.3 Propellant Anchors 174 6.2.2.4 Suction Anchors 175 6.2.2.5 Driven-Plate Anchors 175 6.2.3 Mooring Systems 175 6.3 Handling Heavy Loads at Sea 183 6.3.1 General 183 6.4 Personnel Transfer at Sea 190 6.5 Underwater Intervention, Diving, Underwater Work Systems, Remote-Operated Vehicles (ROVs), and Manipulators 194 6.5.1 Diving 194 6.5.2 Remote-Operated Vehicles (ROVs) 201 6.5.3 Manipulators 203 6.6 Underwater Concreting and Grouting 203 6.6.1 General 203 6.6.2 Underwater Concrete Mixes 204 6.6.3 Placement of Tremie Concrete 205 6.6.4 Special Admixtures for Concreting Underwater 209 6.6.5 Grout-Intruded Aggregate 212 6.6.6 Pumped Concrete and Mortar 213 6.6.7 Underbase Grout 213 6.6.8 Grout for Transfer of Forces from Piles to Sleeves and Jacket Legs 215 6.6.9 Low-Strength Underwater Concrete 215 6.6.10 Summary 215 6.7 Offshore Surveying, Navigation, and Seafloor Surveys 216 6.8 Temporary Buoyancy Augmentation 223 Chapter 7 Seafloor Modifications and Improvements 7.1 General 225 7.2 Controls for Grade and Position 226 7.2.1 Determination of Existing Conditions 226 7.3 Seafloor Dredging, Obstruction Removal, and Leveling 227 7.4 Dredging and Removal of Hard Material and Rock 235 7.5 Placement of Underwater Fills 240 7.6 Consolidation and Strengthening of Weak Soils 245 7.7 Prevention of Liquefaction 248 7.8 Scour Protection 248 7.9 Concluding Remarks 252 Chapter 8 Installation of Piles in Marine and Offshore Structure 8.1 General 255 8.2 Fabrication of Tubular Steel Piles 259 8.3 Transportation of Piling 260 8.4 Installing Piles 262 8.5 Methods of Increasing Penetration 285 8.6 Insert Piles 290 q 2007 by Taylor & Francis Group, LLC [...]... Environmental Aspects of Marine and Offshore Construction 1.1 General The oceans present a unique set of environmental conditions that dominate the methods, equipment, support, and procedures to be employed in construction offshore Of course, this same unique environment also dominates the design of offshore structures Many books have addressed the extreme environmental events and adverse exposures... & Francis Group, LLC 20 Construction of Marine and Offshore Structures Marine organisms play a major role in the soil formation on the seafloor and in disturbing and reworking the surficial soils Walruses apparently plow up large areas of sub-Arctic seafloors in search of mollusks, leading to turbidity and erosion Algae and slime can form very rapidly on the surfaces of stones and riprap, preventing the... Arabian Sea, and offshore q 2007 by Taylor & Francis Group, LLC Construction of Marine and Offshore Structures 32 Australia; as hurricanes in the Atlantic and South Pacific; and as typhoons in the western Pacific The occurrence of such storms in the subtropical and temperate zones is seasonal, late summer to early fall, and is fortunately somewhat infrequent However, while they are easily spotted by satellite... conditions 15 q 2007 by Taylor & Francis Group, LLC 16 Construction of Marine and Offshore Structures Offshore regions extend from the coast to the deep ocean Construction operations have been already carried out in 1500-m water depth, exploratory oil drilling operations in 6000 m, and offshore mining tests in similar water depths The average depth of the ocean is 4000 m, the maximum over 10,000 m, a... role in harbor and river construction In this chapter, the principal environmental factors will be examined individually As will be emphasized in this book, a typical construction project will be subjected to many of these concurrently, and it will be necessary to consider their interaction with each other and with the construction activity 1.2 Distances and Depths Most marine and offshore construction. .. Removal of Concrete Gravity: Base Offshore Platforms 20.5 New Developments in Salvage Techniques 20.6 Removal of Harbor Structures 20.7 Removal of Coastal Structures 672 673 676 679 679 680 Chapter 21 Constructibility 21.1 General 21.2 Construction Stages for Offshore Structures 21.3 Principles of Constructibility 21.4 Facilities and. .. Environmental Aspects of Marine and Offshore Construction 33 more serious than long swells may arrive Quite often, it is the interruption to operations rather than actual storm damage that causes additional costs and delays Cyclonic storms can also spin off the interface between Arctic (and Antarctic) cold air masses and the warmer air of the temperate zones; these produce the typical winter storms of the North... operations even at a distance of several thousand miles The “persistence” of wave environmental conditions is of great importance to construction operations Persistence is an indication of the number of successive days of low sea states one may expect to experience at a given site and season To the offshore constructor, persistence is quite a different thing from percentage exceedance of sea states exceeding... result of river runoff and also as the result of bottom erosion and scour due to current and waves Colloidal silt in fresh water will drop out of suspension upon encountering seawater: this, as well as reduced velocity, accounts for the formation of deltas The zone or band where such deposition takes place is often very narrow, resulting in a disproportionate deposition and buildup in this zone Fine sand,... the waves, with the pressure and hence forces being proportional to the square of the vectorial addition q 2007 by Taylor & Francis Group, LLC Construction of Marine and Offshore Structures 22 While in regular harbor channels, the tidal currents may move in and out along a single path; at most offshore sites, the shoreline and subsurface configurations cause the directions to alter significantly, perhaps . navy. He worked in Marine Construction from 1946 to 1967 and from 1967 to 1971 in Offshore Construction, ending as President of Ben C. Gerwick, Inc., and Manager of Offshore Construction for Santa. 4 0.5 Offshore Construction Relationships and Sequences 5 0.6 Typical Marine Structures and Contracts 8 0.7 Interaction of Design and Construction 9 Chapter 1 Physical Environmental Aspects of Marine. same year and served until 1946. He was assigned as commanding of cer of the USS Scania (AK 40) in 1945. He has worked in marine and offshore construction, or taught about it, for most of the time