Estimating P-and S-Wave Velocities in Fluid Mud Using Seismic Interferometry

Fluid mud plays an important role in navigability in ports and waterways. Characterizing and monitoring the seismic properties of the fluid mud can help understand its geotechnical behavior. Estimation of the wave velocities in fluid mud with high accuracy and repeatability enables investigating the behavior of parameters like the yield stress...

Monitoring shear-stress changes using seismic measurements from controlled sources and ambient noise and optical fibres

Monitoring the nautical depth is vital for the safe passage of water transport. Port authorities worldwide have different navigable depth criteria and use various methods to ensure the safe navigability and manoeuvrability of ships in ports and waterways. These measurements often require a surveying vessel and are limited in repeatability and...

Influence of re-circulation dredging on fluid mud dynamics in seaport emden

Maintenance of the nautical depth in the seaport of Emden, Germany, is achieved by re-circulation of fluid mud using a trailing suction hopper dredger. Continued re-circulation has proven to maintain low settling rates and to keep yield stresses of re-circulated fluid mud below 50-100 Pa, in combination with densities of 1.15- 1.2 t/m³ enabling...

A rheological and microstructural study of two-step yielding in mud samples from a port area

Natural fine-grained suspensions usually exhibit a complex rheological fingerprint – in particular a two-step yielding phenomenon – due to the presence of mineral clay particles and organic matter (often found in a flocculated state). These rheological properties may vary considerably from one location to another due to the differences in mud...

Advances in Maintenance of Ports and Waterways: Water Injection Dredging

The main objective of this chapter is to demonstrate developments in port maintenance techniques that have been intensively tested in major European ports. As regular port maintenance is highly expensive, port authorities are considering alternative strategies. Water Injection Dredging (WID) can be one of the most efficient alternatives. Using...

Non-Intrusive Characterization and Monitoring of Fluid Mud: Laboratory Experiments with Seismic Techniques, Distributed Acoustic Sensing (DAS), and Distributed Temperature Sensing (DTS)

In ports and waterways, the bathymetry is regularly surveyed for updating navigation charts ensuring safe transport. In port areas with fluid-mud layers, most traditional surveying techniques are accurate but are intrusive and provide one-dimensional measurements limiting their application. Current non-intrusive surveying techniques are less...

PRISMA I: Final report

Monitoring of settling and consolidation of mud after water injection dredging in the Calandkanaal

As regular maintenance and relocation of sediment deposits are highly expensive, Port authorities seek more efficient solutions for reducing the costs and CO2 emissions of maintenance dredging. One solution, water injection dredging (WID), is carried out for maintaining the sediment deposits which predominantly consist of clay and silt. WID has...

Using in situ density and strength measurements for sediment maintenance in ports and waterways

Purpose: Fluid mud layers can be substantial in waterways and they can jeopardise navigation when the ship’s keel comes in its vicinity. The nautical bottom has therefore to be properly characterised. Mud density and yield stress are used as criteria to characterise the nautical bottom. For a decade, measuring these parameters in situ has...

Rheological analysis of mud from Port of Hamburg, Germany

Purpose: An innovative way to define navigable fluid mud layers is to make use of their rheological properties, in particular their yield stress. In order to help the development of in situ measurement techniques, it is essential that the key rheological parameters are estimated beforehand. Is there only one yield stress? In which shear rate...

Is density enough to predict the rheology of natural sediments?

Mud is a cohesive material which contains predominantly clay minerals, water, organic matter and some amounts of silt and sand. Mud samples can have complex rheological behaviour, displaying viscoelasticity, shear-thinning, thixotropy and yield stress. In this study, influence of organic matter on the rheological behaviour of different mud...