THE TERMINAL PROBLEM IN COAST PROTECTION

Abstract

This paper introduces the terminal erosion problem which usually occurs down drift of coast protection works, an important aspect of coast protection which is often overlooked. To provide the background to this problem, the formation, replenishment and function of a natural shingle beach is discussed m relation to coast protection. The value of groynes in stabilising the foreshore, the use of artificial beach replenishment, and the effect on the long shore regime following the introduction of a sea wall, are discussed m outline with typical examples. Terminal erosion is described in more detail, with reference to its cause, and illustrated by examples taken around the coast of the British Isles. Suggestions are made for the investigation of the terminal problem, design considerations are discussed, and terminal groynes and various types of terminal works described. Particular reference is made to the permeable type of terminal section. Finally the paper is illustrated by examples of terminal works which have been constructed at two sites m this country. The foreshore conditions and exposure are described, together with the details of the sea wall and groynes, and the details of the terminal works at each site.