J.G. De Gijt

LARGE-SCALE PHYSICAL MODEL TESTS ON SAND-FILLED GEOTEXTILE TUBES AND CONTAINERS UNDER WAVE ATTACK

Geotextile encapsulated sand elements, such as geotextile tubes or geotextile containers, are considered more and more as an alternative material for coastal protection. Uncertainty with respect to the stability of geotextile elements under wave attack is one of the reasons why these systems are not applied widely yet. Therefore, large-scale physical model tests focusing on the stability of geotextile containers and tubes under wave attack have been performed in the Delta Flume of Deltares. The first part focuses at the stability of geotextile containers under wave attack; the second part describes the stability of geotextile tubes under wave attack. For the geotextile containers, observed failure mechanisms are described and analysed qualitatively. For the geotextile tubes, a physical sound formula based on a theoretical approach and verified with large-scale physical model tests is suggested for both stability and deformation (settlement) under wave attack. It was concluded that Froude scaling is not suitable for geotextile containers (due to sand migration within the containers) but can be applied for tubes with a relatively high filling degree.

Cost of quay walls including life cycle aspects

Port authories and other organisations involved in designing and building of port infrastructure are at first glance interested in predicting adequatly the expected costs. This paper discusses the costs development of quay walls versus time. The basis for the costs development of quay walls is discussed on the basis of two methods. The MTI method and MII method. These methods are compared and discussed. Further a database with the construction costs of approximately three hundred quay walls from between 1850 to 2008 enables the composition of relations of the construction costs for several countries and port cities. In addition also relations are developed for different types of quay walls. With the developed model predictions can be made for the costs of quay walls in the future under the assumptions of certain boundary conditions. In addition to the initial costs also the the overall costs are including the effects of lifecycle concepts. Finally some conclusions and recommendations for the application of the developed model are presented and for further research

Upgrading techniques for quay walls

The rapid expansion of trade has led to fast growth of handling of goods in many ports. The ports are the catalysts of development of trade and this will result in large future effects. The increase of ship numbers and sizes will challenge ports in every aspect. Ports have to adapt to the upcoming changes by increasing capacity in every dimension. Quay walls are one of the most essential components of port infrastructure and with growing volumes of cargo and increasing vessel sizes, the demand on these structures is increasing. Efficient transfer at the quay wall interface is required for the commercial and operational success of any terminal or port. This paper comprises many options for creating extra depth in front of quay walls. Not all presented options have been used in practice.

Recommendations for assessing and upgrading old urban quay walls

From the earliest days, quay walls have played an essential role in the shipment of goods in the Netherlands. Therefore the relative old cities have historic quay wall structures. During the life time of these quay walls, the structures have been exposed to various loads due to changing boundary conditions. Currently there is no specific guideline for determining the minimal required safety of these old and historic structures. A specific point of interest is describing the methods and the extension of an inspection in urban areas.