Protection dykes

Geotextile bags are used for a range of marine engineering applications. These include revetments (Fig. 20.3(a)), groins (Fig. 20.3(b)), artificial reefs (Fig. 20.3(c)), slope buttressing (Fig. 20.3(d)), scour prevention (Fig. 20.3(e)) and temporary protection dykes (Fig. 20.3(f)). Some of these applications are discussed in further detail later in this chapter. 

Figure 20.3 Marine engineering applications of geotextiie bags, (a) Revetments, (b) groins, (c) artificial reefs, (d) slope buttressing, (e) scour prevention and (f) temporary protection dykes.

Geotextile tubes are used for a range of marine engineering applications including revetments (Fig. 20.8(a)), offshore breakwaters (Fig. 20.8(b)), protection dykes... 

Figure 20.8 Marine engineering applications of geotextile tubes, (a) Revetments — exposed and submerged, (b) offshore breakwaters, (c) protection dykes, (d) containment dykes, (e) training walls and (f) groins.

Protection dykes (also referred to as levees) are constructed to protect developments from flood damage. This is particularly important in low-lying coastal areas where developments are protected from the effects of coastal storms by the construction of protection dykes along the coastline (Fig. 20.30). Protection dykes have to be constructed high enough and strong enough to resist the effects of coastal storms, because if they... 

Figure 20.30 Geotextile tube—reinforced protection dyke structures.

One technique to prevent the breach of sand protection dykes is to reinforce them internally using a geotextile tube core, as shown in Fig. 20.30. Here, the geotextile tube prevents the breach of the protection dyke stmcture even if the sand cover is eroded from the exposed side of the protection dyke during storms. After the storm the eroded sand is replaced and the geotextile tube is covered again. Protection dykes internally reinforced with geotextile tubes have been shown to be effective erosion prevention stmctures. 

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