This paper presents the results of an experimental study on the 

 behavior of inclined groins and a short disciission on the improvement 

 of groin systems. It supplements a paper presented at the Eleventh 

 Coastal Engineering Conference (Londonj 1968). In the present paper 

 both studies are applied to the design of a groin system located to 

 the south of the Tagus estuary (near Lisbon), where serious erosion 

 has taken place. 



Key Words - Transport-normal/System/Misc-plan/ Accretion/Erosion/ 



T-groins/Europe/Experimental/1900 -1949/1955-1959/1960- 

 1964/1965- 1969/Impermeable/ 



"Land Reclamation and Groin-Building in 7009GR0004 



the Tidal Flats" 



Erchinger, H. F. , Proceedings of the Twelfth 



Coastal Engineering Conference , ASCE, Vol. 2, 



Sept., 1970, pp. 1041-1052. (TC203 .C6) 



Development of new groin designs and groin construction on 

 tidal flats on the North Sea coast of Germany are described. Of 

 interest is the use of polyethylene in groin construction. 



Key Words - Europe/Mis c-materials/Timber/Concrete/Impermeable/ 

 Structural - des ign/Rubb le-mound/ 



'The Effect of Groynes on Eroded Beaches" 7009GR0005 



Price, W. A., and Tomlinson, K. W., 

 Proceedings of the IVjelfth Coastal 

 Engineering Conference , ASCE, Vol. 2, 

 Sept., 1970, pp. 1053-1059. (TC203 .C6) 



Effect of impermeable groins on an eroded beach was studied in a 

 laboratory. A beach was allowed to reach equilibrium for a particular 

 wave climate and supply of littoral material. The foreshore was then 

 manually eroded, and the beach allowed to return to equilibrium with 

 and without groins. It was found that the presence of groins increased 

 the rate of accretion but did not significantly build up the inshore 

 beach beyond the stable levels. Bed levels seaward of the groins were 

 increased. 



Key Words - Impermeable/Accretion/Erosion/Experimental/System/Europe/ 



124 



