164. SILVESTER, R., "Coastal Defense," Proceedings of the Institution 

 of Civil Engineers, Vol. 45, 1970, pp. 677-682. 



Keywords: Accretion, Artificial headlands. Beach fill, Crenulate-shaped 

 bay. Littoral transport. Wave diffraction. Wave reflection. 

 Wave refraction 



Coastal defense incorporates the results of sediment motion (erosion 

 or accretion) along the shore. Although much of this activity is in the 

 surf zone, the ultimate stability of the shoreline is determined by tend- 

 encies seaward of the zone. The effectiveness of groins depends on their 

 location within bays formed between headlands. Such naturally formed bays 

 indicate a beach control system by headland-type structures. The natural 

 bypassing of sediment across harbor and river mouths might be achieved by 

 promoting wave reflection. Short-crested waves could maintain the sedi- 

 ment in quasi-suspension during passage across the entrance channel. 

 Seawalls and revetments constructed on sedimentary coasts only aggravate 

 the erosion problem they are designed to mitigate, because of the influ- 

 ence of wave reflection. Hence, the influence of reflected waves in the 

 near and offshore zone is of great importance. Causes of erosion should 

 be determined before beach renourishment is undertaken on a large scale. 

 All factors combine in an estuary to produce siltation. 



165. SILVESTER, R., "Growth of Crenulate Shaped Bays to Equilibrium," 

 Journal of the Waterways and Harbors Division^ Vol. 96, No. WW2, 

 May 1970, pp. 275-287. 



Keywords: Artificial headlands, Crenulate-shaped bay. Hydraulic model 

 (three-dimensional), Littoral transport. Movable bed. Sand 

 tracer study. Wave diffraction. Wave refraction 



Crenulate-shaped bays are prominent coastal features. If sediment 

 supply is not available, an equilibrium shape is reached. The shape and 

 orientation of the bays is a function of the persistent swell. The final 

 shape is independent of scale and depends only on the wave approach angle. 



166. SILVESTER, R., "Coastal Engineering, I - Generation, Propagation 

 and Influence of Waves," Developments in Geoteohnical Engineering, 

 Vol. 4A, Elsevier Scientific Publishing Company, Amsterdam, The 

 Netherlands, 1974, pp. 217-260, 301-366. 



Keywords: Pile arrays, Submerged breakwater. Wave diffraction. Wave 

 reflection. Wave refraction. Wave transmission 



A textbook of coastal engineering with an emphasis on the needs of 

 the practicing design engineer. This volume concentrates on wave theory 

 and wave-related subjects such as diffraction, refraction, etc. 



167. SILVESTER, R., "Coastal Engineering, II - Sedimentation, Estuaries, 

 Tides, Effluents and Modeling," Developments in Geoteohnical Engi- 

 neering, Vol. 4B, Elsevier Scientific Publishing Company, Amsterdam, 

 The Netherlands, 1974, pp. 71-100, 127-148. 



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