Effect of bow thruster-induced loads on stone displacement near a quay wall: A field measurement

The surge in demand for inland vessel goods transportation has necessitated the operation of larger vessels with increased drafts. These larger vessels generate significant induced loads from their more powerful bow thrusters during berthing and mooring. These loads can lead to scour, which ultimately results in instability of the quay wall. To...

Using CFD to design riprap bed protections downstream of underflow weirs: Weir design of the future

Weirs are constructed inside rivers to manage the water level. On the one hand they need to be designed sufficiently strong to prevent failure or destruction, while on the other hand they need to be economically feasible. If a structure is designed too strong, unnecessary costs are made and the structure becomes too expensive.<br/><br/>One of...

Decay of bow thruster induced near-bed flow velocities at a vertical quay wall: A field measurement

During berthing operations vessels use their bow thruster(s) to improve their manoeuvrability, making them less dependent on the assistance of tugboats. The jet from a bow thruster reflects on the quay wall. It is directed towards the bottom where it reflects, causing high flow velocities over the bed. This may scour the nearby bed when it is...

Experimental study on wave-induced scour in front of sloping coastal structures and the influence of bed protection

The erosion of the seabed in front of coastal structures induced by waves can lead to multiple types of failure instability or function of the structure. On this topic most research has been done into erosion in front of vertical structures. For sloping structures a knowledge gap exists in the understanding of the processes that lead to erosion...

Stability of rock-based emergency measures based on the Grave Weir calamity

On the 29th of December 2016 a large Rhine ship loaded with 2000 ton benzene sailed through the weir at Grave, located in the river Meuse in the Netherlands. The accident created a large gap in the weir and within 12 hours the upstream water level decreased by a maximum of 3 meters. Due to this decreased water level shipping was limited,...

Hydraulic load reduction as a function of depth in a filter layer consisting of logs

The formation of scour holes is a vital thread of retaining the water infrastructure of rivers. Nowadays, protective filters are used to prevent washing away of the underlying material. Rijkswaterstaat started the program 'Stroomlijn’, in which trees (logs) are cut from the floodplains and placed in a sheltered zone of the river to test whether...

The conceptual design of a Tidal Power Plant in the Brouwersdam

Zeeland, located in the south west of The Netherlands, has suffered major casualties and damage due to the flood in 1953. After the disaster, the Dutch Government appointed the so-called Deltacomittee, provided with the task of advising on the execution of the Deltaplan. As part of the Deltaplan, North Sea estuaries has been closed off from the...

Stability of block mattress under non-uniform flow downstream of sluice gate

Downstream of hydraulic structures, the flow is normally of turbulence. This will cause considerable erosions on the gravel bed. To prevent this, block mattress is preferable in many cases. Its effective stabilization and feasibility on construction make it commonly used against scouring problems, protecting underwater pipelines and cables. The...

A new physics-based method for estimating the excess turbulence downstream of a structure

Erosion and sedimentation are natural processes that occur in natural flows.<br/>If the erosion is a threat for a structure, a bed protection is necessary to stop this process. A bed protection usually consists of relatively large stones.<br/>For calculating the required dimeter of the stones several formulae are available, of which the formula...

Stability of block mattresses under non-uniform flow

Block mattresses are widely used bed protection elements under non-uniform flows. Previous studies show that the turbulence of the flow plays a key role on the instability of the mattress. However, in the available design equations, the turbulence intensity is included as a magnification factor roughly and qualitatively defined. Consequently,...