ng pres antwerpen 08122010

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Alternative Dredging „Mud

Conditioning“

Case Study Emden

Surveying Problems and the Physical Behaviour of

Fluid Mud Offer new Dredging Strategies

Workshop Antwerpen, 08.12.2010

Norbert Greiser

GREISER AND PARTNER

Dredging Applications

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Agenda

Determination and Maintaining Nautical Depth

1. Surveying Problems

2. Additional Measuring Technology

3. Fluid Mud

4. Mud Conditioning

GREISER AND PARTNER


Aussenhafen Emden (open basin to River Ems)

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Proof of Nautical Depth by Echosounding

Which echosounding layer represents the nautical depth ?

GREISER AND PARTNER


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1. Surveying ProblemsGREISER AND PARTNER



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1. Surveying ProblemsGREISER AND PARTNER



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Multi Frequency-Echosounding is needed for Sediment Layer Detection

210 kHz

33 kHz? ?

GREISER AND PARTNER


Still open Question: Layer Consistency?

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Agenda

Determination of Nautical Depth



3. Fluid Mud

4. Mud Conditioning

GREISER AND PARTNER


Density / Stiffness Limits for Safe Navigation ?

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Vertical Profiling Probes are Required

GREISER AND PARTNER


Vertical Extension of Navigable Layer(s) ?

Determination of Nautical Depth

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Vertical Profiling Example: Nautical Depth Extension 4,5 m 8,0 m

GREISER AND PARTNER


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Agenda



3. Fluid Mud

4. Mud Conditioning

GREISER AND PARTNER


Origin and Stability of Fluid Mud

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3. Fluid Mud

Progressive Aggregation

SPM from River Weser

Fluorescence Dye FITC

GREISER AND PARTNER


Origin: Clay-Microbes Assemblages /Stability: Sticky EPS

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3. Fluid Mud

SEM Preparation

Acroleine fixed EPS

SPM from River Ems

GREISER AND PARTNER



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3. Fluid Mud

SEM - Preparation

Bakteria Cell with EPS - Filaments

SPM from River Elbe

GREISER AND PARTNER



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Agenda



3. Fluid Mud

4. Mud ConditioningArtificial Liquefaction

GREISER AND PARTNER


Maintaining Nautical Depth

4. Sediment Conditioning

Artificial Liquefaction

GREISER AND PARTNER


Maintaining Nautical Depth by Shear Stress Controlled Liquefaction


KSN - Keep Sediments Navigable – „Emden Method“

GREISER AND PARTNER


Navigable Sediment Layer

Not Navigable Consolidated Silt


Since 1990 a new iteration, “Active Nautical Depth”, objective to keep fluid mud entrained in situ by occasional mixing without ever carrying any material away. Need for “mixing” creates the “Active” component of keeping mud navigable.


GREISER AND PARTNER


Maintaining Nautical Depth by KSN


Throughout 5 years, maintenancedredging needs at Emden reduced tozero, staff from 110 to 4, and costs from€12.5 million to €2 million/yr.

Formerly maintenance dredging and disposal need was 4 million m³/yr.

Important aim is to maintaina “neutral” sediment budget(neither long-term gain or loss of mud).

“Conditioning”, ie. not just re-fluidising mud but also re-oxygenating it in the open hopper.


GREISER AND PARTNER



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Agenda



3. Fluid Mud

4. Mud Conditioning

Thanks for Your Attention !

GREISER AND PARTNER



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KSN - Keep Sediments Navigable

• „Ketchup-Principle“ (Rheology)

GREISER AND PARTNER


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• Navigable Fluid Mud (Rheogramme)

GREISER AND PARTNER


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• Application for Maintenance Dredging

Suspended Matter

Fluid Mud

Fluid Mud

Consolidated Mud

KSN - Keep Sediments Navigable

GREISER AND PARTNER


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Port of Rotterdam Conditioning Trials

GREISER AND PARTNER


Botlek Harbour (2x)

Petroleumhaven 2e

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GREISER AND PARTNER


Botlek Harbour

4 3 3 7 0 - 25 -



GREISER AND PARTNER


Conditioning Area

183.315 m2

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4. Sediment ConditioningGREISER AND PARTNER


400 kHz Multibeam Chart

Dredging Tracks before Dredging Tracks before ConditioningConditioning

Dredging Tracks after Dredging Tracks after ConditioningConditioning

Main Sedimentation

Area of the Relocated Silt

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400 kHz Multibeam Chart

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Dual Frequency Pre- and Post-Dredging Charts

433700

433750

433800

433850

433900

433950

434000

434050

434100

434150

434200

433700

433750

433800

433850

433900

433950

434000

434050

434100

434150

434200

-18-17.75-17.5-17.25-17-16.75-16.5-16.25-16-15.75-15.5-15.25-15-14.75-14.5-14.25-14-13.75-13.5-13.25-13

Location of the Profile

Location of the Profile

Left endLeft end

Right endRight end

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0.00 100.00 200.00 300.00 400.00 500.00

-17.00

-16.00

-15.00

-14.00

Depth (m)

210 kc-Layer

15 kc-Layer

Distance (m)

0.7 m

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0.00 100.0 200.0 300.0 400.0 500.0

-17.00

-16.00

-15.00

-14.00

Depth (m)

210 kc-Layer

15 kc-Layer

Distance (m)

1.5 m

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Nautical Depth Profiling

Clear Shift to Lower

Attenuation Values

Pre- Profile Post- Profile

Navigable

Not Navigable

500 kHz

1 MHz2 MHz

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2e Petroleumhaven

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2e Petroleumhaven

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Starting with Bed Levelling

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Dumping and Conditioning of about 40.000 m3 of Silt

South Part

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Sediment Core after Conditioning

RotterdamPetroleumhaven 2e

Fluidised Mud

Solid Bottom Material

Weak Mud

ng pres antwerpen 08122010

Business

conditioning greiser

norbert greiser greiser

stability of fluid mud

mud conditioning origin

ksn greiser

echosounding greiser

mud conditioning thanks

mud navigable