Geoscience Reference
In-Depth Information
Introduction
1.1 WHY THERE IS A NEED FOR DESIGN RULES FOR
GEOTEXTILE-ENCAPSULATED SAND ELEMENTS
Geotextile-encapsulated sand elements are three-dimensional systems manufactured
from geotextiles (woven and/or nonwoven materials) filled with sand. These elements
can be regarded as innovative, (sometimes) economic and environment-friendly systems
for hydraulic structures along inland and coastal waters, where they form an alternative
to the use of traditional hydraulic materials. There are four distinct types of these ele-
ments, namely geotextile bags, geotextile mattresses, geotextile tubes and geotextile con-
tainers. Table 1.1 provides a summary of the main areas of application for each type.
Experience with these structures has been obtained in many regions, for example,
Australasia, South East Asia, South Asia, Europe, Africa, North and South America.
However, there is the impression that broader application is possible if knowledge of
the performance of geotextile-encapsulated sand elements is more readily available. An
initial step has already been taken in The Netherlands with [14] to make current knowl-
edge of geosystems more accessible to a broader public, so that they can be incorporated
in the planning stage as a structure variant. Furthermore, an extensive description of
the available knowledge is provided by Pilarczyk [22]. Based on the work presented by
Pilarczyk and other sources (see the bibliography) this manual will provide design rules
for the most common geotextile-encapsulated sand elements. Where possible, the design
rules have been validated and, where appropriate, the limitations stated. The target group
for this manual comprises project managers, designers, administrators and supervisory
bodies involved in the planning and execution of hydraulic and coastal structures.
1.2 DOCUMENTSTRUCTURE
This manual contains a summary of design rules and calculation examples for
geotextile-encapsulated sand elements based on the available theories and describes
the standard construction methods for these types of structures.
Chapter 2 describes the general design approach applied to these geosystems. In
addition to the general design approach to be followed for all hydraulic structures, the
safety aspects and the required properties of geotextiles are considered. Chapters 3 to 6
examine in more detail the various applications and element types; geotextile bags (3),
geotextile mattresses (4), geotextile tubes (5) and geotextile containers (6). Details cov-
ered include filling methods, applied loads, required strengths, stability, durability and
positioning accuracy. Examples are given along with pointers for practical application.
