Hydraulic structures

compilatiefoto waterbouwkundige constructies

Flanders Hydraulics Research examines the behaviour of hydraulic structures and their interaction with the environment. They are affected by e.g. current, ship waves, wind waves and water pressure. The expertise we gain in this area of research is aligned closely with our goal to constantly pursue safe, smooth and smart mobility. Furthermore, we want to help create an infrastructure that is integrated and managed effectively for society and the economy.

For water-retaining structures such as sea and river dykes, we investigate the effect of the erosive action of hydraulic forces on the stability of the dyke or components thereof and determine the impact of the potential failure of the dyke.

When new locks are designed or existing weir lock complexes are renovated, we provide advice and/or a hydraulic study. In this manner, we also contribute directly to the movement of fish through weir lock complexes using fish passes. We also perform hydraulic studies for other hydraulic structures such as dams, inlet and outlet structures and culverts.

Flood Defences

Locks

Fish passes

Other hydraulic structures

Projects


Flood Defences

Flanders Hydraulics Research specialises in policy-supporting advice and (preliminary) design, monitoring and evaluation of flood defence structures. We have specific expertise in banks, retaining walls, river dykes and sea dykes and carry out research in breach sensitivity, failure rates, failure mechanisms and breach growth.

For coastal protection structures such as sea dykes and dunes, groynes, breakwaters and storm walls, we investigate the interaction of waves, currents and sediment movements. We do this using in situ measurements, scale model tests and advanced numerical models for wave and current forces which give us insight into tides, wave impact, wave run-up and wave overtopping.

We also carry out dimensioning of the revetment of river dykes, sea dykes, overflow dykes and ring dykes for flood control areas. First we analyse or measure the erosive action of hydraulic forces acting on the dykes and then we determine the need, type of revetment and dimensions.naar boven

Locks

Levelling system design
Flanders Hydraulics Research specialises in studies for levelling systems in locks. Using a desktop design, we estimate the required flow section for the levelling system. We then draw the geometry and examine whether there is any air entrainment or cavitation.

With the help of various specialised software packages (including our own developed programme vul_sluis), we simulate the filling and emptying of the entire lock chamber and identify the forces that occur on vessels in the lock chamber. We can also build a scale model of the lock chamber or simulate the flow in the lock chamber with CFD modelling. Similarly, the local flow pattern of specific components of the levelling system can be simulated and analysed.

We perform field measurements in existing or new locks to increase the ships’ comfort during filling or emptying of the lock chamber and to optimise the operation of the lock system. We therefore measure:

  • the variation in the time of the rising speed of the water;
  • the slope of the water level in the lock chamber;
  • the opening speed of valves or gates;
  • any hydraulic losses of the lock chamber levelling system;
  • waves in the outer port or canal reaches caused by the locks.naar boven

Bottom protection design
We also design the bottom protection in the outer ports of the lock or alongside the quay walls. For this, we first determine the hydraulic forces on the bottom using a desktop study or numerical modelling. Based on this result, we propose the type of bottom protection required as well as the dimensions. The hydraulic forces on gates (e.g. by waves) can also be determined.

Fish passes

To resolve issues with fish migration, Flanders Hydraulics Research conducts research for the hydraulic design of fish passes. This often happens in close cooperation with the Research Institute for Nature and Forest (INBO), which plays an advisory role on ecological aspects and criteria. Through desktop studies, we determine the most appropriate fish pass type (e.g. V-shaped basin stairs or vertical-slot passages) and the best spatial and hydraulic integration.

In the event of more complex design or research topics, e.g. creating an optimal attraction flow or implementing in more complex spatial and/or hydraulic situations, we conduct studies with scale models and numerical models (e.g. CFD modelling).

Flanders Hydraulics Research not only provides advice and research on the design of new fish passes, but also evaluates the hydraulic performance of existing fish passes. We perform field measurements for this including water levels, discharges, current velocities and current patterns.naar boven

Other hydraulic structures

Flanders Hydraulics Research specialises in studies on all types of water-bearing structures such as inlet and outlet structures, drainage culverts, dams, sluices, supply and discharge to pumping stations and turbines, etc.
We use desktop studies to determine the necessary flow section, to estimate the hydraulic losses, to design the stilling basin and to control the air entrainment at the inlet of the structure

To simulate the discharge, current velocity and pressure in the pipes, we use specialised software packages. Based on a scale model study or CFD modelling, we can determine the design of the stilling basin or the flow pattern (into or out of these constructions) in greater detail as well as the hydraulic loss of the structures.

We identify the current velocities at the bottom using numerical models or scale models to determine the need, type and dimensions of the bottom protection next to the structures.

We also conduct field measurements to gain more insight into the hydraulic operation of these structures. We determine the discharge through the structures and the water level upstream and downstream of the constructions. The current velocity into or out of the structure can also be measured as well as the position of gates or valves.naar boven

Projects

Recently the following studies are performed:

  • Hydraulic design of a filling and emptying system for the new Royers Lock
  • Study of the erosion and sedimentation near the weir lock complex of Asper
  • Design of the bottom protection near weir lock complexes
  • Filling and emptying system of the new middle mitre gates for the lock of Zemst
  • Hydraulic design of the filling and emptying system and a mud capturing device for the Deurganckdok lock
  • Hydraulic revision of the combined inlet and outlet sluices for inundation areas with controlled reduced tide
  • Design of erosion protection for the dikes of inundation areas with controlled reduced tide

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