Offshore breakwaters and shore evolution control by Krystian W. Pilarczyk and Ryszard B. Zeidler

1. Introduction. 1.1 General. 1.2 Types and functions of coastal structures. 1.3 Offshore breakwaters. 1.4 Functional requirements and design. 1.4.1 General postulates. 1.4.2 Design considerations and methodology. 1.4.3 Design procedures. 1.4.4 Failure and probabilistic design facets. 1.4.5 Final design and designer's checklist. 2. Coastal boundary conditions. 2.1 Overview of boundary conditions. 2.1.1 General. 2.1.2 Selection of hydraulic boundary conditions. 2.1.3 Description of wave loading and wave structures interaction. 2.1.4 Geological and geotechnical conditions. 2.2 Coastal topography. 2.2.1 General outline. 2.2.2 Crenulate- shaped and pocket beaches. 2.2.3 Far- field and near field effects. 2.3 Hydraulic boundary conditions. 2.3.1 Sea level. 2.3.2 Wind. 2.3.3 Waves. 2.3.4 Joint probabilities. 2.4 Nearshore currents. 2.4.1 Forcing factors and longshore currents. 2.4.2 Cross-shore velocities. 2.4.3 Tidal and residual currents. 2.4.4 Other nearshore currents. 2.4.5 Models of nearshore currents. 3 Sediment transport and shore profile evaluation. 3.1 Sediment transport. 3.1.1 Introduction. 3.1.2 Longshore sediment transport. 3.1.3 Cross- shore sediment transport. 3.1.4 General rules and computer algorithms. 3.2 Shore profile evolution. 3.2.1 Equilibrium profile. 3.2.2 Morphologic features of profiles and their description. 3.2.3 Final remarks. 4. Waves at structures. 4.1 Overview of wave transformation modes at structures. 4.2 Wave reflection. 4.3 Wave energy dissipation. 4.4 Wave run-up and run- down. 4.5 Overtopping and piling-up. 4.6 Wave transmission behind breakwater. 4.6.1 General guidelines. 4.6.2 Findings and details contributed by various authors. 4.6.3 Wave diffraction. 4.6.4 Miscellanea. 4.7 Theoretical treatment transformation at structures. 4.7.1 General description. 4.7.2 Some theoretical methods. 4.8 Scour. 4.8.1 General incidence and extent of scour. 4.8.2 Short evaluation of present knowledge. 4.8.3 Simple prediction methods. 5. Functional and geometrical design. 5.1 Introduction. 5.2 Performances of offshore breakwaters. 5.2.1 Morphological interactions. 5.2.2 Submerged breakwaters. 5.3 Experimental background for geometrical dimensioning of offshore breakwaters. 5.3.1 General. 5.3.2 Occurrences and overall dimension of shore features at offshore breakwaters. 5.3.3 Shape and volume of shore features at offshore breakwaters. 5.3.4 Comments and remarks. 5.4 Geometrical design guidelines (morphological dimensioning). 5.5.1 General. 5.5.2 Emerging breakwaters. 5.5.3 Submerged breakwaters. 5.5.4 Confining downdrift effects. 5.6 Miscellanea. 5.6.1 Berm breakwaters. 5.6.2 Sills and perched beaches. 5.6.3 Tandem breakwaters. 6. Structural design. 6.1 General. 6.2 Design of rubble mound structures. 6.3 Slope protection and revetments. 6.4 Composite systems using geotextiles. 6.5 Other systems. 7. Materials. 7.1 Design process and assessment of materials. 7.2 Rock. 7.2.1 Evaluation of rock type at sources. 7.2.2 Properties and function. 7.2.3 Construction induced properties. 7.2.4 Durability (armourstone degradation rates ) and design implications. 7.2.5 Testing and evaluation. 7.3 Other materials. 7.3.1 Clay. 7.3.2 Sand. 7.3.3 Gravel. 7.3.4 Unbound aggregates. 7.3.5 Grass. 7.3.6 Geotextiles. 7.3.7 Bituminous bound material. 7.3.8 Cement bound materials. 7.3.9 Industrial by products. 7.4 Composites materials and systems. 7.4.1 Gabions. 7.4.2 Mattresses. 7.4.3 Block mats. 7.5 Assessment of concrete armours units (NRA 1991) 7.5.1 General requirements. 7.5.2 Categorization of units. 7.5.3 Unit strength. 7.5.4 Hydraulic performances. 7.5.5 Stability. 7.6 Quality control. 8. Construction aspects. 8.1 Introduction. 8.2 Specific aspects of site and location. 8.3 Equipment. 8.4 Positioning systems and survey methods. 8.5 Quality assurance. 8.6 General construction aspects and work methods. 9. Monitoring, maintenance and economics. 9.1 General. 9.2 Monitoring. 9.2.1 General. 9.2.2 Preconstruction monitoring and surveys. 9.2.3 Periodic monitoring during implementation. 9.2.4 Periodic post- construction monitoring. 9.2.5 Wind data and water level measurements. 9.3 Maintenance. 9.4 Economics. 9.4.1 General. 9.4.2 Offshore breakwater cost components. 9.4.3 Cost analysis. 9.4.4 Evaluation and remarks. 10. Worldwide experiences and case studies. 10.1 General experience. 10.2 Case studies.

ENG