Revaluation of dredging costs in reservoirs and its impact on reservoir financial performance

The research focuses on sedimentation in reservoirs. Subjects include settling distribution in a reservoir, dredging and flushing of sediment in reservoirs, impact of sedimentation on reservoir performance and financial effects of long term sedimentation in reservoirs.

Physical Modelling of Offshore Pipeline Flotation during TSHD Sand Backfill

The influence of flocculation on the development of a sediment plume

A lot of uncertainties exist about the impact of deep-sea mining on the Benthic environment. One of these uncertainties concerns the sediment plumes created by the mining operation. The return slurry released above the sea floor creates a large plume of sediments. With numerical models the behavior of such plumes is modelled in order to minimize...

Particle Degradation during Vertical Transportation: Contribution of Abrasive Wear on Polymetallic Nodule Degradation

Manganese nodules have been lying on the deep sea soil for centuries before they became known. The first ones to discover the nodules were Murray and Renard, during their scientific cruise between 1872 and 1876 (Murray and Renard, 1876). The Clarion-Clipperton Zone, located between Mexico and Hawaii, appears to have a virtually inexhaustible...

Draghead Analysis: An analysis of the draghead's physical processes to determine the trailing forces and the production

In dredging there are a lot of opportunities to improve the production processes and to make the production cycle more efficient, especially the excavation process of the draghead. The aim of this research is to determine the trailing forces and to estimate the production of the draghead. Besides that, the goal is to get more insight into how...

Erosion Mechanisms below a vertical plain Jet on a Non-Cohesive Soil Bed

This experimental research is focused on fail mechanisms in non-cohesive soil beneath the jet with a Jet Erosion Test(JET). A vertical plain jet impinges fluid to a sand bed, which causes zero shear stress beneath the jet averaged over time. Many erosion theories would say that no pick-up happen at that point. <br/><br/>E_c=u/(√(H⁄d) √(ΔgD50 ))...

Creating an online grain size estimator based on hopper sensor data and iterative hopper settling models

This research focuses on the development and feasibility of an online grain size estimator for a trailing suction hopper dredger (TSHD), based on the mass balance within a hopper, and using hopper settling models. The idea of the grain size estimator is to use existing hopper settling models iteratively for a certain time window with ‘online’...

Optimization of the fluidization system of the trailing suction hopper dredger

The Trailing Suction Hopper Dredgers (TSHD) are typically used for the transportation of soil. The soil in the hopper can be removed by hydraulic transport using water jets and the discharge at the bottom level of the hopper. The soil fluidization and transportation is jet assisted. The unloading process can take quite some time; the unloading...