Design and construction of containment bund using geotextile tubes in Singapore

Abstract

In a major port development project in Singapore, a containment bund using modified geotextile tubes (M-GT) has been designed and constructed. The purpose of this bund is to create a containment area to contain any sediment plumes due to construction activities (i.e. dredging activities, dumping activities and sand-filling activities) from being transported towards the nearby forest reserve area by currents. In addition, the containment bund also serves as a retaining structure to retain dredged materials during the sand-key construction and other port expansion works. This paper presents the key consideration in the design and construction of the geotextile containment bund. Among the challenges faced in this project were the great water depth of this containment bund location (>25m) and high traffic volume in Singapore water course as the site is next to the existing operating port terminal. The design of M-GT has taken into consideration the potential high tensile forces developed during the filling process of M-GT, the free fall dropping of the M-GT, and the impact of M-GT onto the seabed. Instead of conventional fill material of sand and clayey soil from the borrowed pit nearby, this project seeks to reuse the discarded soil from other excavation projects on land or sea via mixing with cement as filling material in the modified geotextile tubes. Extensive field instrumentation and monitoring were carried out during and post construction phase to verify the design and the performance of the geotextiles containment bund system.