Marine engineering geotextile containers

Geotextiles and geotextile containment units used in marine engineering... 

Sand fill is normally used for geotextile containment units in marine engineering applications because it is permeable, it is stable when the sand fill is dense, and it does not undergo volume changes with time, ie, settlements. Fine-grained fills stabilised with cement or polymer have also been used in geotextile containment units for marine applications however, this is a new, emerging development and is not discussed further in this chapter. 

Three types of geotextile containment units are used in marine engineering, differentiated on the basis of shape and volume geotextile bags, geotextile tubes and geotextile containers (Fig. 20.2). 

Figure 20.2 Types of geotextile containment units used in marine engineering, (a) Geotextile bags, (b) geotextile tubes and (c) geotextile containers.

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.

Geotextile containers are used for a range of marine engineering applications which require placement of the units at water depth. These include offshore breakwaters (Fig. 20.10(a)), containment dykes (Fig. 20.10(b)), artificial reefs (Fig. 20.10(c)) and slope buttressing (Fig. 20.10(d)). Some of these applications are discussed in further detail later in this chapter. 

One technique to improve the stability of breakwaters and containment dykes con-stmcted on soft foundations is to use geotextile reinforcement across the base of the stmcture (Fig. 20.19). This basal reinforcement technique has been used successfully for many years in the onshore construction of embankments on soft foundation soils, and is discussed in detail in chapter Geotextiles used in reinforcing foundations. Because of its cost—benefits, this technique has also been used in marine engineering structures over the past 20 years. 

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