Geoscience Reference
In-Depth Information
Table 2.1
Application areas of geotextile-encapsulated sand elements.
Geotextile
bag
Geotextile
mattress
Geotextile
tube
Geotextile
container
Application
Beach groyne
X
X
Breakwater
X
X
X
Hanging beach
X
X
X
Dune toe protection
X
X
Channel repair
X
X
X
X
Land reclamation
X
X
Underwater reef
X
X
Bed protection
X
X
Bank protection
X
X
X
Temporary dams
X
X
X
Sediment management
X
X
X
X
practice, the uncontrolled placement of armour stone against the geotextile skin,
and from vandalism of the exposed geotextile skin. Due to these susceptibilities,
and because geotextiles lose strength over time when exposed to ultra-violet light,
permanent structures utilizing these geosystems are almost always covered with one
or more layers of granular material. Depending on the application, and the type of
geotextile used, a cover layer may be omitted for temporary structures.
For large elements (e.g. geotextile tubes) no damage should occur to the geotextile
skin as this will allow the sand-fill to be lost. For small elements (e.g. geotextile bags)
limited damage can be sustained provided there are sufficient surrounding elements in
the structure that are not damaged.
These geosystems may also be used in combination with materials other than
sand-fill (for example sludge). Applications exist where fine soils are used in combi-
nation with geotextile encapsulation to drain and prevent their erosion. This manual,
however, focuses exclusively on sand-filled encapsulation.
The appendices of [14] describe a number of geotextile containment projects
already carried out. Table 2.1 contains a brief summary of the application areas involved.
2.2 DESIGN APPROACH
The construction of a hydraulic engineering project comprises several phases, from
initiative to aftercare. Each phase generates an end-product that allows the next phase
to begin. In chapter 2 of [11] and chapter 2 of [22] this process is described in detail.
This manual is specifically focused on the planning phase (i.e. the design process), and
is intended to provide guidance for the rational design of geotextile-encapsulated sand
element structures.
Irrespective of the contract form chosen, this manual can be used as an aid to gen-
erate both the Programme of Requirements (specification of functional requirements
