OCEN 201 Introduction to Ocean & Coastal EngineeringSlide 2Slide 3Slide 4Coastal ErosionSlide 6Beach NourishmentEconomic value of BeachesCoastal ProcessesSlide 10Shore Protection Projects- BreakwatersSlide 12Slide 13Slide 14Waterway NavigationSlide 16Slide 17Slide 18Shore Protection Projects- GroinsSlide 20Slide 21Shore Protection Projects- RevetmentsSlide 23Slide 24Slide 25Shore Protection Projects- SeawallsSlide 28Slide 29Slide 30Laboratory ResearchHaynes Coastal Engineering LaboratorySlide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50OCEN 201Introduction to Ocean & Coastal Engineering Coastal Processes & StructuresJun [email protected] Processes • Typical beach profile and coastal zone - Beaches dissipate wave energy and are constantly adjusting to the wave environment (shoaling, wave breaking, sand bar & surf zone, Fig. 4-1, pp80) • Littoral Transport (sediment transport) - Long shore transport (parallel to the shoreline, long shore current) - Offshore-onshore transport (perpendicular to the shoreline)Beach Profile Fig. 4-1, pp102Consequences of Coastal Processes • Beach erosion (Natural or Man-Made Causes) Table 4-1 pp104 (old E. pp81)• Beach Protection & Nourishment -coastal structuresCoastal ErosionCoastal ErosionCoastal ErosionCoastal ErosionHwy 87 Texas CoastHwy 87 Texas Coast• Infrastructure• Property• Environment• Infrastructure• Property• EnvironmentBeach NourishmentBeach NourishmentEconomicvalue ofBeachesEconomicvalue ofBeachesCoastal ProcessesCoastal Processes• Wind and Waves• Wind and Waves• Sediment Transport• Sediment TransportCoastal StructuresBreak waters: (rubble mound, sheet pile, stone asphalt, Dolos, concrete cassions, floating structures (coastal & offshore))•Jetties & Groins (normal to the shorelines)•Sea walls Bulkheads, Revetments, G-tubes•Sand Bypassing (continue the littoral process; passive and active)•Ports, Harbors and MarinasShore Protection Projects- BreakwatersShore Protection Projects- BreakwatersShore Protection Projects- BreakwatersBreakwaterWaterway NavigationWaterway NavigationJettiesRUBBLE MOUND BREAK-WATERVERTICAL BREAKWATER FIGURES:Design ConsiderationsShore Protection Projects- GroinsShore Protection Projects- GroinsShore Protection Projects- GroinsShore Protection Projects- RevetmentsDifferent Kinds of DolosConcrete & Reinforced ConcreteDolosVarious Sea WallsShore Protection Projects- SeawallsConstruction of Galveston seawall ~ 1902Ports and HarborsPorts and HarborsNew South Wales and Queensland, AustraliaSand Bypass FacilityJetties at the entrance of Tweed RiverOutlet of the sand pumpLaboratory ResearchLaboratory ResearchResearch Experience for Undergraduates (REU) ProgramResearch Experience for Undergraduates (REU) ProgramHaynes Coastal EngineeringLaboratoryWave Refraction*, Diffraction & Reflection•Wave Refraction: The direction of waves may change when they enter from deep to shallow water or from shallow to deep water.Deep-1Shallow-21q2 12 1sin sinSnells law: , is the phase velocityCC Cq q=Shallow-1Deep-21q2q2qWave direction is normal to the wave crest lineExamples of Wave refraction in the costal zone, see pp 117 Fig 4-21 (old Edition: pp 90 Fig. 4-12).Wave direction is normal to shore line. In other words, wave crest-line is parallel to the shore line.Wave RefractionPhenomena of wave shoaling (wave enters from deep water to shallow water)•Wave refraction•Wave length becomes shorter•Wave group velocity is reduced•Wave becomes steeper, which leads to wave breaking. Wave breaking leads to the generation of long-shore current.Definition of the surf zone: from the first breaker (due to water depth) to the shore line.General Refraction Analysis2 2 - Along a ray line, wave direction is always parallel to it or wave creatline is normal to it.Wave energy density - Average wave energy per unit length /8 / 2Wave grouE gH gAr r= =Ray Linep (energy) velocity1In intermediate water depth 2 sinh 21In deep water , 2 2 2In shallow water , 1gggkhC nCk khCC nkC gh C nww� �= + =� �� �= = == = =1. Steady state (time-independent)2. Wave characteristics are inpendent of y (long shore direction)3. Bottom contours is paralell to the shore line which is striaght0 10 0 1 10 010 0 0 001 1 1 11100 Subscript '0' denotes it at 122g gg pg pg gC E b C E bC CC b C bEC b C bEH EHE=== ==deep waterWave energy flux = Eenergy conservation (no wave breaking)gC E11000101 , known as the refraction coeff. , known as the shoaling coeff.2S RRpsgH EK KHEbKbCKC= ===pp117-118 (old edition pp91-92)•Wave Diffraction: When wave energy is transferred laterally to wave direction, this phenomenon is known as wave diffraction.Wave diffraction occurs when waves passing by a surface piercing body. It may occur in deep or shallow water.An example in shallow water is wave diffraction behind a breaker water. See Fig. 4-22 at pp119 (old edition Fig. 4-13 at pp93). (internet examples)•Wave Reflection and Transmission: when the water depth suddenly changes, part of the incident wave energy is reflected in the direction opposite to the incident wave direction, part energy continues to propagate (transmit) in the incident wave direction. : incident wave height; : reflected wave height : transmitted wave height Reflection Coeff. ; Transmission Coeff. i rtrrittiH HHHCHHCH==00Reflection Coeff. of a plane slope tan /where is the slope is the incident wave height is the wavelength in deep water.iiH LHLbxb=Surf parameterUsing Fig 4-23 at pp 120 (old edition Fig. 4-14 at pp 94), you may determine the reflection coefficient based upon the surf parameter.Wave RunupWave runup is important to the design of the height of coastal structure, such as seawalls and breakwaters.0Hunt (1959)tan for tan 0.1/where is the wave runup. is the wave height see Fig. 4-24 (p121) (old edition Fig. 4-15 (p95))RHH LRHqx q= = >Sediment Transport 32s Buoyancy index: 1where the specific weight of a sphere the specific weight of fluid the diameter of sphere the kinematic viscosis ssgdBdgg nggn� �= -� �� � 50ty of fluid.Because the diameter of the sediment is not uniform, is replace by , which is the median diameter of the sediment. is non-dimensional.sd dBSediment Transport 323Buoyancy index: 1In general,