Projects

Dredging

Antwerp - Dredging of new quay wall

A new quay wall was built at the B2 Canal dock in Antwerp by order of the Antwerp Port Authority. The more than 800 meter long quay wall is one of the heaviest in Belgium and is suitable for a water depth of up to 17 meters. The new quay wall ensures that larger and deeper ships can from now on moor.

Ghent Dredging dredged the zone between the old and the new quay wall, and the zone in front of the old quay wall, to a depth of -12.5m TAW. The Company Aertssen, our partner in the Temporary Trading Company, took care of the dry earthwork between the old and the new quay wall. Over the entire length of the quay wall, this meant a dredged volume of no less than 1.4 million cubic meters. At the same time, the old quay wall was also demolished step by step.

The work had to be completed in a record time of 30 weeks and that was also successfully completed. Ghent Dredging used its cutter suction dredger “Ouistreham” and its two largest dredging pontoons GDVI and GDVII for this purpose. At the height of the yard, 20 barges were at work to transport all the dredged land to the various destinations.

Blankenberge - Port entrance

The entrance of the Port of Blankenberge has been dredged several times by our CSD Ouistreham.

Bruges - Ghent-Ostend Canal

A quantity of 1.077.000m³ has been dredged, transported by barges and pumped into spoilareas.

Although being a maintenance dredging contract it also included straightening out a bend in the canal at Beernem, inclusive of bank protection works to the newly-formed embankments.

Between Aalter and Beernem as well as at Bruges war ammunition was found during the dredging operation.  To cope with this particular problem the dredged material was separated from the ammunition by use of screening.  Dredged material was washed through the screen, whereas the ammunition remained behind on top of the screen to be disposed of.

At Bruges it took us 3 months to finish this part, while the other location lasted 6 months.

Among the war ammunition removed we found hand grenades, air bombs, obusses and devices containing lethal gasses.


Caen - Canal Caen Ouistreham

Ghent Dredging has been awarded by the "Ports Normands Associés (PNA)" the contract for the dredging of a new turning bassin for sea ships on the canal from Caen to Ouistreham (FR).  With our cutter suction dredger, we dredged 200.000m³ of sand on a distance of 2.200m far.  The sand was pumped into two sandfill areas that we constructed before the start of the dredging works.

River Deûle - Upgrading to 3.000 T-capacity

Upon completion of the upgrade of the embankments, dredging started the dredging works to allow ships of upto 3.000 tonnes on the river Deûle.

Stage 1 consisted of dredging the downstream part of the river. The majority of the dredged silt has been deposited in the designated spoil areas near Quesnoy-sur-Deûle. After completion of this spoil area, clayground has been used to cover the silt. Finally recovered topsoil from the spoil areas has been put on top of the clay to enable these areas to be refurbished into a new green area in the near future.

Another part of the dredged materials has been shipped to a designated spoil area some 100km away near St. Omer.

Hamme - Durme

Maintenance dredging of the river Durme started for client Waterwegen and Zeekanaal. The purpose of the contract was twofold:  

a. To enlarge the cross-sectional area of the river and by doing that to reinstate its discharge capacity.

b. To create 3 stockpile-areas with sand for future use in ringdikes of inundation areas to be build along the banks of the River Durme.

A quantity of approx. 400.000m³ was extracted from the riverbed . The dredging was being carried out by our CSD Ouistreham. The sand was being transported through a floating and a land-based pipeline over a distance of up to 2.500m in the stockpiles called Bunt, Klein Broek and Groot Broek.

After the construction of the bunds of each fill area dredging effectively started.  The end of the area to be dredged was approx. 500m upstreams of the historical Mira-bridge at Waasmunster.

The silt has been dryed by actively lagooning and has been disposed off at a later stage to an allocated depot.

Hazebrouck - Upgrading Canal d'Hazebrouck

Ghent dredging executed the maintenance-dredging operation on the Canal d'Hazebrouck.

After a long tender procedure (most economically advantageous tender) this contract has been awarded to Ghent Dredging based on its technical and financial proposals by client USAN (Union des Syndicats des Assainissement du Nord).

A total quantity of approx. 18.000m³ of heavily contaminated silt has been dredged and disposed of at Ghent Dredging's soil-treatment centre at Ghent.

Dredging was carried out using a so-called "Menzimuck"-digger. Excavated soil was transported along the canal in 40m³ barges, pushed by 4 small boats. The spoils was reloaded by digger in lorries with watertight containers and transported to Ghent. To enable the digger to unload the barges a temporary bridge across the canal has been constructed.

Upon completion of the dredging works a 250m timber sheetpile bank protection has been placed within the urban area within the centre of La-Motte-au-Bois. Finally the road on top of the embankment was resurfaced.

Upon completion of the dredging contract the client proceded with the entire refurbishment of the embankment of the canal.


Ypres - Ypres-Yser Canal

For many years maintenance dredging had been non-existing on this canal due to lack of funding.  Finally a budget was raised to dredge the canal to such an extend that a restricted passage to shipping was created.  About 50% of the contract, at the Ypres side of the canal, has been carried out by Ghent Dredging.

This contract could serve as a perfect example in the way our dredging and environmental divisions were complementary to each other.



Dredging was carried out using a pontoon mounted 14-tonnes excavator.

Elevator barges loaded with silt were discharged alongside a pontoon equipped with an excavator fitted out with a DOP-1815 dredge pump.  After adding water to the sludge the pump discharged the silt into dewatering areas.

Once inside these areas dredged silt is pumped into geocontainers added with polymers.  Through the addition of polymers the dewatering process is accelerated and after a couple of days silt has turned into soil.

Movie dewatering of geotubes (avi 6718KB)

Rotterdam - Port of Rotterdam

The Rotterdam Port Autority is carrying out a refurbishment scheme of many of the old City Docks.

Within the Johan Friso Dock a turning bassin has been filled in with sand obtained from two different borrow areas.Before filling started, (polluted) silt -some 110.000m³- had to be removed.

Filling started using sand from a borrow area at Amazone Dock, sand being spread in 0,50m layers through our barge unloading suction dredger connected up with a spraying-pontoon through a floating pipeline.

After the implementation of approx. 50.000 no. of vertical drains to speed up the settlement of soft sub-strata layers an additional 350.000m³ of coarse sea sand was reclaimed and placed by a trailing suction hopper dredger.  Also included in the contract was the construction of a 670m long waterproofed sheet pile wall using AZ13 and AZ26 sheetpiles, each 22m long.

The new industrial area thus created was completed with a new bank protection.

Roubaix - The Roubaix Canal

The Roubaix Canal Dredging Scheme between the Belgian-French border and the River Deule has been carried out as part of the European Union funded 'Blue Links' project.

Some 160.000m³ has been dredged on both the Roubaix Canal and the River Marque.  Included in the contract was the construction of a dewatering area,  devided into three separate catchment areas on top of the waste mountains, in the past created by the local gypsum industry at Wattrelos.

The bottom layer of the bassins consisted of bentonite matting and drainage material.  The effluent was discharged through this drainage system.

Additionally a 1.200m² consolidation area was created to catch the effluent originating from the dewatering areas.  Analysing and disposal of this water has been conducted in accordance with French environmental legislation.

Included as well was the construction of two quay walls to provide for truckloading of the dredged material.

Dredging was carried out using two small backhoe dredgers and a fleet of small barges.  An average daily output was realised of 450-1.000m³.

Subsequently another 20.000m³ capacity silt area has been created adjacent to the E17 Motorway embankment.  Its 40.000m² surface has been waterproofed entirely with a MRC-membrane as well as an external drainage system to allow analysed water to drain back into the canal.

Finally The locally known PCUK-site was used to dewater approx. 130.000m³ of silt with a reduced water percentage of 30%.

Rouen - Dredging Port of Rouen

Rouen Port Authorities awarded JV Ghent Dredging-Dutch Dredging the contract to enlarge and deepen de turning basin at Hautot-sur-Seine (about 10km downstreams of Rouen). The contract is part of the Port's program to deepen the river Seine from Le Havre towards Rouen with one meter to make the port accessable to larger vessels.

The contract comprises the removal of approx. 800.000m³ of sand, silt, gravel and limestone. The dredged materials are being transported by means of tugs and barges over a distance of 30 km to Yville-sur-Seine. At Yville-sur-Seine a barge-unloading dredger empties the barges and dispose of the materials into various fill areas over a distance of approx. 1km.  

The main features of the project are:

  • 400.000 m³ dredging upto 9 meter below CD with dipper-dredger 'GD VI'
  • 300.000 m³ dredging upto 15 meter below CD with cutter-suction dredger 'Ouistreham'
  • 100.000 m³ maintenance dredging within the existing turning basin using a trailing hopper dredger
  • The above-mentioned quantities are being pumped into previous "ballastières" at Yville-sur-Seine. Surplus process-water is being discharged into the River Seine using a controlled pumping system.
  • Also included in the contract was the removal of a concrete caisson (50,00 x 11,00 x 3,50) and a 550m long sheet pile wall.

St-Omer - Canal Neufossé

A maintenance dredging contract on the Canal Neufossé between Dunkirk and Valenciennes has been carried out on behalf of our client VNF. Some 110.000m³ has been taken out at the time. Twelve years on, within the same area a similar contract has been awarded, this time about 150.000m³ has been taken out. Both times, similar equipment has been used, i.e. a dipper-dredger, tug, dry-well barges and a barge-unloading dredger.

Included in the contract was the (re)-creation of a 25 acres fill area, taking into account additional measures with regard to the existing surrounding environmental areas, such as earthworks, sealing of the fill area, overflows, etc. The discharge of the dredged material was carried out using a closed-water circuit to avoid the loss of material into the canal.

Spiere - Spiere Canal

A maintenance contract was carried out for client SPW (Département des Voies Hydrauliques) on the Spiere Canal, starting at the French-Belgian border up to the upper reaches of the River Scheldt.

Along a distance of 8 km a total quantity of 45.000m³ of polluted silt has been dredged and transported to the Upper Scheldt in small barges.  From there on, the silt was reloaded into bigger barges.

From there on the dredged material was transported another 25km upstream to an SPW-owned lagoon.  Unloaded by a long-reach digger the silt was ultimately hauled with water-thight dumptrucks into the lagoon.

After consolidation the silt was then finally disposed of by means of barges in yet another depot.

After having carried out dredging works on the upper reached of the Spiere Canal (Canal de Roubaix) and the River Marque on French territory for our client VNF (Voies Navigables de France) the Upper Scheldt is yet again - after 30 years - connected with the River Deûle.

The fully restored canal was inaugurated in the presence of a great number of dignitaries from both France and Belgium by allowing the first pleasure crafts to sail yet again along this historical part of our heritage.

Dredging works Roubaix

Earth Movement

Bruay - River Scheldt (France)

As part of the realignment of the Trith-Mortange section of the River Scheldt Ghent Dredging has been awarded and subsequently completed this contract by its client Voies Navigables De France (VNF) to create a 500m long embankment.  The ecological construction consisted of approx. 6.500m³ to create a wetland-like riverbank and the construction of 3 lagoons to encourage wildlife in a semi-aquatic environment.

Additional works consisted of submerging tree-stumps, the construction of a meadow and reseeding the embankment.

A rustic meadow was then sown along the bank.

Mechelen - Zennegat

In the context of the Sigmaplan the National Water Authorities (W&Z) is constructing a range of flood planes along the tidal rivers to reduce the risk of flooding in urban areas. The Zennegat contract at Battel is part of the Sigmaplan. The area involved is known as the mouth of the River Dijle, where the Rivers Dijle, Zenne and Nete merge in the River Rupel. The scope of the contract is to create a 150-acre flood plane to reduce the tidal impact.

As a result the River Dijle will get a bigger area with controlled flooding capacity , resulting in a reduced risk of flooding in both the adjacent area and the wider region. At the same time rare wetlands, so characteristic for this area, will flourish again.

As of now, each flood tide a reduced quantity of water from the River Dijle will now flow through the lock at the Zennegat. At ebb tide the lock will discharge the water back into the river. The artificial tidal movements will slowly create gullies, creeks and wetlands, an ideal habitat for rare species. Moreover, fish can continue to swim through the lock.

During extreme weather conditions the area will be allowed to flood in a controlled matter. When water levels rise to a set level, the water will flow into the Zennegat, using the overflow dike.

This overflow is the former Dijle dike, lowered and reinforced to allow water to flow across.

Because the Zennegat is able to store a large quantity of water, urban area will be safeguarded from floodings.

It is predicted, that the Zennegat storage area will be used several times per annum. After each flooding the lock will discharge the water into the River Dijle in a controlled matter.

Sequedin - Deule

At Sequedin the River Deule has been widened.  Locally, just before reaching the Port of Lille, the canal narrows due to the remains of a former power station.

Along this stretch a new quay wall has been constructed.  Our contract involved the removal of surplus soil surrounding this new quay wall and incorporating either end of the quay wall into the existing riverbank.

The main problem consisted of the removal of the old foundations of the power plant and two concrete abutments of a former pedestrian bridge.  About 5.000m³ of concrete has been demolished.

After removal of the concrete foundation, earth works started in earnest including the construction of the river banks and its protection.

After dry-removal of the soil the old retaining wall was removed.  Its steel sheet piles have been taken out using a pontoon-mounted telescopic crane.

Finally the remainder of the soil has been dredged and disposed of using barges.  In all 70.000m³ of soil has been removed.

To store this soil an old fill area at the village of Emmerin was re-opened.  Its bunds were raised using dry excavated material from Sequedin as well as locally found soil.  In the final stage of the project dredged material from Sequedin was dumped into this area.

Zele - "Scheldebroek"

At Zele Ghent Dredging raised the Scheldebroek Controlled Flooding Zone´s surrounding bunds and reinforced them up to Sigma Standards (Sigma-Scheme is the Flemish Flood Prevention Scheme).

Also included in the contract were road works, the creation of access to surrounding fields, ponds, planting of shrubs.  The required quantity of sand (80.000 m³) was dredged using our 85-tonnes backhoe dredger at St.Amands discharging it into elevator barges and spoiled by using our barge unloading suction dredger.

Civil Engineering

Antwerpen - Graan dock

The Graan Dock was closed of, using a steel combi-wall.  The area behind was filled in with spoiled sand. The purpose of the project was to create new dock areas to replace the old delapidated dock.

The dredging and filling part of the contract was carried out by Ghent Dredging as a subcontractor to maincontractor Besix nv.


The dredging operation comprised of the removal of a layer of polluted silt from the old dock and the disposal of it in our lagoon at Ghent, as well as dredging non-polluted material to be re-used in underwater areas at the Churchilldock in Antwerp.

In advance of the piling of the combi-wall, a soil-improvement with sand was carried out . To carry out this soil-improvement, the area was dredged upto 18m below waterlevel.

After construction of the combi-wall by the main-contractor the old Graan Dock was hydraulicly filled in layers of 30cm with required specified sand.

This sand was hauled from an existing stockpile by dumptrucks.  Using a temporary bridge the lorries dumped the sand into barges.  With the deployment of our barge-unloading Rhosnes a mixture of sand and water was pumped through a 400m long floating pipeline to a spraying pontoon. With the help of a RTK-positioning system sand was sprayed in 30cm layers.

To meet the stringent compaction requirements the whole area was compacted using a heavy compaction device.

To fill the entire area a total quantity of 160.000m³ was used.

Calais - Rehabilitation works of Perré Risban

As part of the rehabilitation works of the "Perré Risban" forming the access channel to the outer harbour west of the port of Calais, Ghent Dredging has been assigned the bank protection works, whilst our partner Spie Batignolles has executed the civil engineering works.

With a length of 460m, the existing "perré Risban" consisted of an anchored sheet pile wall, supporting a layer of sandy marl protected by a reinforced concrete slab. The "Perré Risban" in its present design dated from the 70's. The sheet pile construction has been heavily corroded, causing many disorders (fissuring of the slab, flow of fine materials).

The adapted solution is a new combi-wall (combination of sheet piles with H-profiles) standing autonomously in front of the existing sheet piles, and the infill of the space between the sheet pile walls. This way, the existing sheet piles no longer play a role in supporting the embankment.

The new construction is protected wave-attacks by a layer of quarry stones 1/3T.

Our work consisted of:

  • Dredging of a slot at the base of the existing wall to allow for the piling of the new combi-wall
  • Filling in the intermediate space with a layer of sand
  • Demolition of the old concrete slab and excavation to allow for the infill of the rock fill
  • Placement of a geotextile associated with a granular filter
  • Installation of a first layer of quarry stones (60/300kg)
  • Installation of a second layer of quarry stones (1/3T) 

To realize our scope of the contract, two sets of equipment have been deployed:

  • A floating set: Consisting of a pontoon mounted excavator (85T) and two barges with tug

  • A land-based set: consisting of two crawler excavators (45T) and two dump trucks operating from the crest of the embankment

A total quantity of 16.000m³ quarry stone, 8.000m² geotextile and 10.000m³ backfill has been incorporated.

Calais - Calais Port Pier n°8

The scour-protection at Pier n°8 has been refurbished as preparation for the arrival of the latest generation of super-ferries.

The existing protection had to be removed (and dumped at high tide on the beach to be recovered at low tide) and the surrounding area deepened. Upon completion of the dredging operation the new rock armour scour-protection was placed.

Work has been carried out within a tidal window of approx. 7m, resulting at high tide in a working depth of 18m below waterlevel.

To allow for a reduced layer of rock armour, stones with an extreme high density of 3,15 t/m3 have been used. Due to its high density this rock armour cannot be found in local quarries and had to be imported from a quarry in the Vendée-area in France and transshipped through the port of Sables d'Olonne. A total quantity of 14.000 tonnes has been used to achieve the required result.

Deûle - Bankprotection from Deûlémont to Lille

The banks of the river Deûle have been realigned and strengthend stretching from the French-Belgian border upstreams towards Lille.

Voies Navigables de France has awarded Joint-Venture Ghent Dredging - Soetaert this contract to realign and reinforce both banks with sheetpiles, gabions and rocks over a distance of 20km.

The project is part of the widening and deepening of the river Deûle to upgrade inland shipping to CEMT-class V, enabling ships of up to 3.000 tonnes to use this waterway. The actual widening and dredging works were also partially carried out by Ghent Dredging.

The upgrading works of the river Deûle in the North of France to CEMT-class V is part of the Seine-Scheldt Project of with the masterpiece of the entire project will be the new canal between Cambrai and Compiègne .

To be able to carry out the works, the existing banks were cleared from trees and bushes and the existing stone-protection removed.

After vibration of the sheetpiles (in general up to 1m below waterlevel) the new banks have been built up with rocks, size 20/80 kg to approx. 1m above mean waterlevel. The remainder of the banks have been graded with (top) soil and reseeded.

Non-exploded ammunition was found in the downstream area between Deûlémont and Quesnoy-sur-Deûle. After thoroughly side-scanning both banks the decision was made to reconfigurate one of the diggers with a safety-pack to allow for safe dredging and recuperation of non-exploded ammunition found within the sheetpile area.

In the upstream part within the Lille-area works were to be carried out in an urban area. Problems arising from working in build-up areas such as working in confined spaces, underground cabling and the many bridges were causing obstacles to be dealt with. These circumstances necessitated the use of special techniques such as the construction of an underwater cutter soil mix wall of 500 metres.

Some areas have been built using gabions. Existing gabions in deplorable condition have been removed and replaced with cubic gabions 1m by 1m on top of a foundation with gabion-matrasses.

Ghent - Blaarmeersen

At Blaarmeersen Estate, along its famous watersports area, its beach area has entirely been refurbished.

After preliminary works, earth works have been carried out, to include a new sewer system and paving.  To complete the contract the really visual results of it all: the construction of the esplanade, water slide, sanitary facilities, a pedestrian bridge and the ever present joy for children: toys!!!

And this all to the satisfaction and the happiness of the citizens of this beautiful City.

Ghent - The Reep / Diocese Quay

After nearly 60 years, the redundant filled-in connection between the Lys and the Scheldt has been reopened. The existing parking area and the existing plants has been removed. The old quay walls,  hidden under the pavement, has been exposed and tested for their stability. It was decided to partially upgrade and partially renew it.

At the Reep side, a completely new quay wall has been constructed using a secant wall covered by a masonry brickwork . The existing quay wall at the Diocese Quay side was cleared and reinforced by means of micropiles and HDI piles. In addition, a new quay wall was cast in concrete, finished with masonry at the front.

At the same time, the infrastructure, such as the sewage system and roads of the Reep, the Diocese Square and the Diocese Quay were completely refurbished and finished in cobblestones.

At the refurbished side of the Diocese Quay, a low-level quay was made in Belgian blue stone to create a secluded area to relax.

The final phase of the works was the further excavation of the formally filled-in part of the river Scheldt. The opening-up moment of Lys and Scheldt, after so many years, was extensively covered by the local and national media and was the subject of many festivities.

The many years of experience of our skilled employees were required to successfully complete the project as a challenging combination of various disciplines (road construction, earthworks, hydraulic engineering and dredging works) and has made the Diocese Quay-Reep zone one of the nicest places in Ghent.

Ghent - Gravensteen

At Ghent a temporary dam around Gravensteen Castle was removed. The dam has been put in place to allow the restauration of the outer walls of the Castle.

The dam has been excavated back to the original level. The adjacent park area has been reinstated with topsoil and reseeded.

The result: after many years the Gravensteen Castle is yet again a moated castle.

Ghent - Moervaart

Client Maritieme Toegang and Port of Ghent had awarded JV Besix-Ghent Dredging the contract to provide a scour protection at the Moervaart at Ghent.

Located at the utter downstream part of the canal 2 types of scour protection were placed over a total lenght of 900m alongside the northern quaywalls.

The purpose of the contract was to reinstate the scour as a result of shipping traffic, causing an imminent stability problem to the quaywall.

Second goal was to dredge the waterway.

TYPE 1 : rock-armour

Over a length of 450m by a width of 24m a (temporary) bottom protection at variable depths was carried out using stones. Firstly overdepths in front of the quaywall were filled out using steel slag material size 32/90 mm, covered by a layer of armour stones size 10/300kg and partly penetrated with colloïdal concrete.

TYPE 2: Asphalt-matrasses

In the zone to be covered by asphalt-matrasses, the area had to be dredged in advance up to the solid sub-strata.

Before any matrass could be placed deeper areas were filled out with steel slag material size 32/90mm.

After levelling the full width of 20m was ready to be covered by asphalt-matrasses.  Alongside the toe of the channel the edge was protected with a layer of stone, with a width of 4m.

Sealing alongside the quaywall was established using colloïdal concrete.

Finally the main channel was again dredged to the required depth.  The dredged material, sand and silt, were disposed of at the Rodenhuize lagoon area.

The matrasses, measuring 10 by 5m, were fabricated at the adjacent Moervaartquay area in a 120 by 18m working area. For that purpose the existing road had to be realigned locally.

In the working area itself a number of 20 sets of prefab formwork units have been erected.

After positioning the steel wire webbing each formwork was filled with a 30cm layer of asphalt.  The asphalt in each formwork was then leveled with a beam to achieve an even layer.

Using a specially-designed hydraulic lifting frame, designed by our subsidiary Deco nv, jointly with a 160 tons crane the matrasses were lifted from the quay and stockpiled onto a pontoon.

After positioning the matrasses were placed using the frame, equipped with a RTK-positioning system with an centimeter-accuracy on top of the steel slag foundation.  The seams between the individual matrasses were sealed using hydro-mortar.

In all 21.300m³ of silt has been removed, 10.560m² of asphalt-matrasses have been placed, about 11.000m³ of steel slag have been used and 17.670 ton of armour stones have been incorporated.

Ghent - Submerged pipeline

As a sub-contractor to Visser & Smit Hanab a twin submerged pipeline has been placed near Ghent-Muide, consisting of two steel pipelines (dia. 500mm) designated to the transportation of gas.

The contract included the construction of the two receiving steelpiled boxes on both banks, dredging the required trench and assisting the main contractor during the operation to submerge the pipelines across the Houtdok.

Also included was the refill of both the trench and the receiving boxes and the renewal of the quaywalls along a restricted length of the Houtdok.

Geraardsbergen - Gavers

At provincial Gavers Estate a beach of just over 6.000m² has been created inclusive of sports and leisure facilities.

To allow for dry excavation, a temporary bund has been constructed across the pond.  After completing this bund in the pound became the perimeter of the protected swimming area. Finally additional works with regard to recreation completed this contract.


Hamme - Lippenbroek

Hamme-Lippenbroek has been transformed into the world´s first Controled Reduced Tidal Zone.  The system has been developped by the Flemish Authority to answer today´s challenges to prevent large-scale floodings in the River Scheldt catchment area.  The purpose of this 25 acre overflow area is to reduce extreme high water levels in the River Scheldt during excessive flood tides in allowing this area´s lowered river embankment to be overtopped.  As soon as river water levels go down and back to normal levels the zone will drain itself.  At the same time this allows the Environmental Agency to create valuable biotopes.  This second objective was to create a nature reserve.  To achieve this, a lock has been incorporated in the existing river bank, which allows the creation of an artificial tidal zone with muddy wetlands.

Hamme-Lippenbroek proves both objectives viable.

Ghent Dredging was involved in the construction of the ring-shaped bund for which over 160.000m³ of soil has been moved as well as the construction of the sheet-piled foundationed concrete lock.

Harelbeke - Gavers

At Harelbeke, County Estate "de Gavers" has been thoroughly renovated with the construction of a new poolhouse, the reinstatement of a diving site, a renewed riverbed for the Gaverbeek watercourse, a new reception building and a brand new watersports building.

Ghent Dredging has been involved in all of these activities in various phases of the contract. Our part in the upgrading included:

  • Construction of timber jetties
  • Construction of floating jetties, fixed with tubular piles
  • Construction of azobé hardwood surfacing along the watersports building
  • Construction of concrete access roads, concrete surfacing at the cafeteria, food paths, petanque playing fields and a beach volley pitch
  • Construction of a slipway, incl. a black-top access road
  • Construction of a complete new sewage-system
  • Construction of a public utilities infrastructure for water, gas, electricity, telephone/data, glasfiber over a distance of approx. 800 meters
  • Construction of a cobbled walkway
  • Earthworks with the infill of a part of Gavermeer Lake
  • Horticultury works

Some years before, Ghent Dredging started works at Gavers with the construction of a restricted swimming area, consisting of a sheet-pile wall and a concrete floor. On top of the sheet-piles a steel construction has been jointed to serve as a support of the timber bridge around the swimming area.

Knokke-Heist - Reconstruction bird islands in nature reserve The Zwin

Ever since the late 1990's the Zwin nature reserve is suffering from a considerable silting up and as a result not enough seawater is reaching the inner part of the reserve. For this reason the existing artificial bird islands are losing their attraction for birds to settle. The birds population on and around the areas decreased over the years.

As part of the European ZTAR-nature project, Section Nature and Forest awarded Ghent Dredging a contract to create a number of new bird islands to offer new opportunities for a number of birds. In particular the seagull, the common tern and the avocet.

Included in the contract was the construction of a weir/bridge. The purpose of its construction is to make sure sufficient water will be available around the islands at all times and allowing access to the public.

To make sure the incoming seawater would stay within the nature reserve, some of the existing channels have been filled up, while other channels have been dug, ensuring a perfectly regulated water management of this nature reserve.

Under another contract about 20 acres in the north-easterly part of the Zwin area, close to the estuary of the main Zwin-channel, have been lowered by removing the nutrient-rich toplayer. Its purpose is the recreation of the original flora. Through lowering the area is rejuvenated. The resulting mud areas should evaluate into an area rich in a variety of species such as samphire and statice, the locally well-known "Zwinneblomme".


Lixhe - Weir

At Lixhe, near Liege, we have been awarded the contract by the regional Rivers and Water Authorities (SPW-Voies Hydrauliques Liège) to reinstate the scour protection at the downstream side of the Lixhe weir.

About 30.000m³ of the existing scour protection had been washed away during periods of extreme waterflow on the River Meuse. The void that had occurred was threatening the stability of the weir.

The execution of the contract was limited by various restrictions:

  • Working within an environmental sensitive area
  • The weir remained operational during the works
  • A very limited access downstreams to mobilize and demobilize our floating plant
  • The required rock had to be imported over water

Due to its extensive experience Ghent Dredging has been able to carry out this contract. Local quarries were used to produce the 54.000T of stones required. The imported rock was discharged at the upstream side of the weir, loaded on dumptrucks and, at the downstream side loaded into a split barge.

The split barge was positioned by the use of a spud-legged pontoon, mounted with a 50T digger, equipped with a DGPS positioning system, enabling to place the various sizes of rock accurately.

The rock had to been placed into 3 different layers with 3 different types of stones, i.e. 10/250kg, 450/1000kg and 1000/3000kg.

Mechelen - Binnendyle

At the Zandpoortvest at Mechelen the Binnendyle has been opened up again after 40 years. The existing car park between the two buildings of the Thomas More College has been converted into a green, open meeting place with gently sloping banks and a jetty.

In order to realize this work, a work platform was first constructed in the river Dyle. This in order to enable the construction of the required secant walls.  Anchored secant walls were built to guarantee the stability of the adjacent road once the banks were dug out. After the finishing of the secant walls, the concrete walls including its coping were realized. These were required, among other things, to be able to realize the requested wheelchair ramp up to the lowest square.

Once this was done, the concrete channel could be demolished. First the roof of the tube was scalped, and subsequently the walls were sawn through and removed. The lower part of the existing channel still serves as a riverbed.

In the final phase of the contract the conversion was completed by removing the existing banks, rebuilding the sewage system and the casting of a concrete foundation to be completed with a staircase in natural cut-stone steps.

The finishing touch is the paving of an 1.800 m² area in Chinese granite.

Monceau-sur-Sambre - Weir

At Monceau-sur-Sambre Ghent Dredging carried out repair works at the downstream side of the weir and its scour-bed.

The reported damage:

  • Rupture of the concrete bottom of the weir. As a result a 3 m deep scour-hole had developed. Along approx. 100m about 800m3 of rip-rap was placed to fill the hole.
  • Damage to both banks, consisting of subsidence of both banks.

The location where the damage has occurred made a hard job to repair with:

  • Stricted access by land
  • Shallow water and limited headroom
  • Huge variations in both waterlevels and flows

The job in hand consisted of:

  • Dredging downstream of the scour area
  • Removal of the concrete floor around the scour area
  • Filling out the scour area, using armour stones 300/1000 kg on top of a bottom layer of rip-rap 0/180 mm.
  • Penetration with colloidal concrete of the armour stones
  • Reinstating both banks, using armour stones, concrete and cut-stones.

To carry out the job a self-propelled pontoon, mounted with a 20T digger, equipped with DGPS was used.

The pontoon had to be modified several times to be able to carry out the various stages of the contract, i.e. dredging, rock dumping, incorporating concrete and fixing both banks.

Some quantities:

  • 2.300T armour stones
  • 400m³ colloïdal concrete
  • 300m bank reinstatement

Mortagne/Trith St. Léger - River Scheldt

At the Mortagne-St.Léger section of the River Scheldt its riverbanks have been refurbished as part of a contract awarded by the French River Autority (VNF).

Approximately 15km of riverbanks have been refurbished using 46.600m² of filterfabric and 75.000 tonnes of stones.  About 88.000m³ of soil have been shifted.

In global 15,2km of shore had to reprofiled.  Also 46.600m² of geotextile and 75.000 tons of rocks were placed.  As finishing touch, 125.000m² was sowed.

There was a complete soil transport of 88.000m³.

Roeselaere - Renovation "Klein Bassin"

For many years this area has served as a water storage area to the surrounding textile mills.  After the demise of the industry it soon turned into a neglected and rapidly deteriorating area.  The area itself was covered in weeds for many years.  Some time ago the decision was made to turn it into a public area.

After emptying the bassin the contaminated silt has been removed, its banks reshaped and furnished with a stoney bank protection.  At both ends steps have been constructed bordering an artificial waterfall.  Slopes provided with shrubs and an agreable public lighting turned the area into an intimate walking space.

The finishing touch was the installation of a beautiful bridge midway the bassin to be used by pedestrians and bikers.

St-Pieters-Leeuw - Reconstruction of the Zuunbeek

The Flemish Environment Agency is working on an integral redevelopment project along the Zuunbeek in Sint-Pieters-Leeuw. The works will limit the flooding in Negenmanneke and promote the ecological and scenic recovery of the Zuunbeek.

In the past, the natural catchment area of the Zuunbeek was mainly adapted to, for example, supply the existing water mills with sufficient water. About forty years ago, the stream has been straightened and deepened to allow a speedy discharge of excess water. Wetlands were filled up and  paved areas, such as new roads and houses, increased. The accelerated drainage and the increased paving was the cause of increased floodings downstream at Negenmanneke.

De Zuunbeek and her valley are now better equipped. There will be more room for water storage by making the brook meander and by creating flood plains. Meanders ensure diversity through steep and soft banks, deep and shallow parts. That way, there are parts where the water flows faster and more slowly. This increases the self-cleaning ability of the watercourse and increases the biodiversity in the stream and its banks.

The works have been divided into four subprojects, of which Ghent Dredging has carried out the first subproject Volsembroek.

At the beginning new meanders have been dug. The straightened Zuun has been filled up in some areas, but in most places the straightened Zuun has been retained and will serve as an emergency overflow and storage at high water levels. Upstream of the project area no new meanders will be dug, but "flow deflectors" have been placed in the water.Due to these obstacles in the water, the watercourse is forced to find a different route and, as a result, the watercourse will begin to wriggle itself.

A new dam was built near the existing Volsem storage basin. This can regulate the water level upstream. In addition, a dike was constructed to allow the nature reserve behind the dike to serve as a controlled flood area during heavy rainfall. This flooding area has a capacity of 204.000m³.

Vilvoorde - "De 3 Fonteinen"

At Vilvoorde `Three Fontains` City Park has been refurbished.

After catching and relocating fish from the pond its water was pumped into the River Zenne.  After the silt has been removed, the park´s fontain has been dismantled (to be replaced in a later stage) and its banks furnished with timber sheet piling.

Overflows have been incorporated to provide the system with the required water levels.

Upon completion of the first pond, the water from the second pond was pumped into the first one to allow the process to be repeated.

Upon completion of the second and final pond the remainder of the required water was topped up with the benefit of the existing wells.

Industrial area

Ghent - Schipperskaai

The coming years will see a huge make-over at the North of the city of Ghent. Amongst it the old quarter Oude Dokken, once the center of the industrial history of the city, will be given a new destination due to the implementation of new projects and neighborhoods.

The first feat in this area was the reconstruction of the Schipperskaai. Using the Batavia-bridge, this will provide the access to the city centre and will be the heart of the new neighborhood, with the concrete plant and the harbor cranes as its eye-catchers.

Prior to the reconstruction, the polluted soil had to be removed. This as a result of the use of the area when timber sleepers were treated with creosote.

After the sanitation of the area a new sewage system was build, serving as the drainage system for the building yet to be build along Schipperskaai, including a pipe-into-pipe renovation of some existing concrete drainage pipes to ensure the drainage to the Handelsdok.

The final part of the renovation was the Schipperskaai itself. The main feature being the old railway line, reused to  preserve the old industrial look. These are being held in place using in-situ concrete sleepers

Roads consist of cobbles, cast in concrete. The area is designed as a pedestrian promenade. Smooth-finished retaining walls will serve as seats for those sauntering the waterside and concrete steps will give access to the buildings yet to be erected.

The icing on the cake are two additional harbor cranes, erected along the existing one.

Ostende - Avenue de la Minque

Plassendale - Industrial area

Ghent Dredging has been involved in the construction of Plassendale 1 Industrial Estate.

The 6 year contract is regarded as being the perfect example in which a mix of all our in-house experience has succesfully been used.

Road works include the estate´s access road as well as Greenbridge´s roads and roundabout.  Greenbridge being University of Ghent´s Science Park.

Earth works comprised of the construction of foundations for buildings, the foundations for the Ostend to Plassendale railroad line and the excavation of its inland dock of which 200.000m³ has been excavated, while the remaining 100.000m³ has been dredged using our cutter suction dredger.

Spiere - Schelde

Geotechnical

From time to time Ghent Dredging carries out geotechnical site investigations in joint-venture with specialized consultants.

On the River Meuse we collected bore-hole information for our client AIDE in joint-venture with Geolab.  Together with MT's geotechnical department we did the same for BAM (holding company responsable for the new River Scheldt crossing) at the Port of Antwerp's Straatsburgdock.

Samples were taken at regional (polluted) silt-storage site Callemansputte at Ghent, also in joint-venture with MT"s geotechnical department. We also took samples on the River Scheldt, with a tidal difference of some metres.

Bottelare - Scholen OVAM

Gent - Bodemsanering Wasserij

Lokeren - Oude gasfabriek OVAM

Lokeren - Bodemsanering OVAM

Mechelen - Injecties OVAM

Zomergem - Scholen OVAM

Steenweg 250 9810 Eke
info@ghentdredging.be
T +32 9 222 61 57

BTW BE 0415.953.915
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