2
1.2 – Motivation
Current understanding of hydraulic stability of stacked geotextile tube structures is limited at best and the potential for future application with better understanding is vast. A geotextile tube breakwater could be both an innovative and ―low-cost‖ solution for various coastal projects.
1.3 – Objectives
The objective of this thesis was to:
• Determine the hydraulic stability of multi-layered geotextile tube structures. • Define critical aspects of this type of structure and hydraulic conditions that will
increase and decrease stability.
• Provide a method to calculate the hydraulic stability. • Evaluate findings against current methods and formulae.
1.4 – Methodology of Research
The objective for this research was achieved by means of:
Firstly, a literature study was done on current application and design practice. Parallel to the literature study consulting firms with current or previous geotextile tube structure design projects were visited and queried on their experience. Hydraulic laboratories that have completed hydraulic testing of geotextiles for coastal applications were visited in South Africa, Germany and the Netherlands. From the literature review it was determined that the best way to determine the hydraulic stability will be a 2D physical model (see Chapter 2).
Secondly a 2D physical model was constructed that could accurately replicate a typical application area for the intended structure. Different structure configurations with varying hydraulic conditions were tested (see Chapter 3 and 4).
Thirdly, comparing the data collected from these tests against current methods and analysing the data to generate a new method for calculating hydraulic stability (see Chapter 5).
Fourthly, using the analysed data to draw conclusions and make recommendations for application and further study (see Chapter 6).
