Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Presented by Tom Wang, P.E., and Kathy Ketteridge, Ph.D., P.E.January 28, 2016
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Overview of Presentation
• Introductions
• Examples and design considerations of beneficial use (BU) opportunities
• Predictive modeling for BU
• Dredging, transport, and placement methods for BU
− Innovative construction materials and methods
• Case study discussion
• Questions
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Integrated Approach is Key to Success
Design for Beneficial Use
(BU)
Constructability Concerns
Construction Equipment and
Methods
Predictive Modeling
Goals of BU Project
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Beneficial Use Design Guidance
• USACE publications− EM 1110-2-5026 Dredged
Material Beneficial Uses
− DRP and DOER papers and case studies
• USEPA− EPA842-B-07-001 Beneficial
Use Planning Manual
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Beneficial Use (BU) Opportunities
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Beneficial Use Opportunities
Confined Disposal
Facility (CDF)–Shoreline
Development
Shoreline Remediation
Cap
Confined Aquatic
Disposal (CAD)
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Beneficial Use Opportunities, continued
Habitat Restoration -
Mitigation
Beach Nourishment
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Predictive Modeling for BU Projects
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Physical Stability of Placed Sediment• Objective: Evaluate short- and
long-term physical stability of placed material due to hydrodynamic forcing
• Tools: ADCIRC, STWAVE, Delft-3d, SWAN, M2D and others
• Data needs
− Site conditions
− Design conditions
− BU sediment characteristics
Maximum Predicted Current Field Around BU Island (M2D Model)
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Physical Stability of Placed SedimentHydrodynamic Forcing Conditions• Tidal currents
• Estuarine processes
• Wind-waves
• Vessel wakes
• Propeller wash
• Riverine currents
• Outfalls/stormwater
Simulation of Hurricane Katrina for Port of Gulfport (wind stress)
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Keyport Lagoon, U.S. Navy
Tidal Currents (ADCIRC) and Excess Shear Stress
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Hancock County Living Shorelines, Mississippi Sound
Wave Energy along Shoreline (SWAN)
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Esquimalt Harbour, British Columbia, Canada
Prop Wash Evaluation
• CFD Code• Need to predict
specific velocity field behind the prop
• Evaluate scour potential based on predicted velocity field
• Example shows velocity field around constructed containment wall
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Sustainability (SLR)
• Objective: Evaluate impacts to project over design life based on predictions of sea level rise
• Tools: Hydrodynamic models and GIS spatial modeling tools
• Data needs
− Site conditions− Design conditions− Habitat conditions and characteristics− Sea level rise estimates (typically
through 2100)
Transformation of Tidal Wetlands in DE
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Geotechnical Modeling• Dredged
material bulking and settlement (short-term)
• Foundation consolidation (long-term)
• PSDDF Model
– Settlement during construction
– Long-term consolidation
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Contaminant Mobility (Benthic)
• Mobility of contaminants through the placed sediments
• Groundwater pathways
• Reible Model (1998 EPA Cap Guidance document)
• AQFATE
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Contaminant Mobility(Suspended)
• Objective: Assess water quality impacts resulting from dredging
− Turbidity− Dissolved contaminants
• Tools: ADDAMS DREDGE and STFATE modules; EPA Plumes
• Data needs − Site conditions− Sediment characteristics− Dredge characteristics and
operations− Disposal operations
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Summary of Predictive Modeling for BU
+ Considered++ Important+++ Critical for Design
Beneficial Use Options Physical Stability
Sustain-ability
Contaminant Mobility (Benthic)
Contaminant Mobility (suspended)
Geotechnical Considerations
Confined Disposal Facility/ Shoreline Development
+++ + +++ +++ +++
Confined Aquatic Disposal +++ ++ +++ +++ +++
Beach Nourishment +++ + +
Habitat Restoration/Mitigation +++ +++ ++ +++
Sediment Remediation Cap +++ +++ +++ +++
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Dredging, Transport, and Placement• Key considerations in equipment and method selection
− Intended beneficial use of dredged materials at placement site
− Distance between dredge and placement sites
− Dredging vs. placement production rates
− Substrate suitability of dredged material for beneficial use
− Sediment contamination
− Placement site timeframe to achieve functionality
• Short-term dredge material bulking and settlement
• Long-term consolidation (sediment and foundation)
− Dewatering or treatment needs
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Dredging, Transport, and Placement (cont.)• Key considerations in equipment and method selection
− Predictive modeling results
− Empirical laboratory or bench-scale testing results
− Environmental impacts
• Water quality impacts at dredge and placement sites
• Habitat impacts
• Ability to employ construction BMPs to mitigate impacts
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Dredging, Transport, and Placement (cont.)
Beneficial Use Options Dredging Method (Mech, Hydr)
Transport Method (Barge, Pipeline)
Clean or Contam.Sediment
Active DewateringTypically Used
Treatment Typically Used
Confined Disposal Facility/ Shoreline Development
Both Both Both Yes Sometimes
Confined Aquatic Disposal Mechanical Barge Both No No
Beach Nourishment Hydraulic Pipeline Clean No No
Habitat Restoration/Mitigation Both Both Clean No No
Sediment Remediation Cap Mechanical Barge Clean No Sometimes
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Dredging and Transport Technologies• Mechanical
– Barge transport– Unlimited transport distance– Low bulking (i.e., near in-situ)– Intermittent placement– Debris is relatively easy– Lower production rate
• Hydraulic– Pipeline transport– Restricted transport distance– High bulking (i.e., hydraulic slurry)– Continuous placement– Debris is challenging– Higher production rate
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Mechanical Dredging Technologies
Derrick Dredge (aka Clamshell Dredge)
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Hydraulic Dredging Technologies
Swinging Ladder Cutterhead Dredge
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Hydraulic Dredging Technologies (cont.)
Trailing Suction Hopper Dredge
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Dredged Material Transport and Screening
• Transport equipment depends on dredge type and staging/processing needs
− Barge transport
− Pipeline transport
− Staging area availability and size
• Staging/processing depends on final placement site
− Debris screening
− Dewatering
− Treatment
− Overland transport
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Mechanical Dredge – Barge Transport
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Hydraulic Dredge – Pipeline Transport
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Screening Debris
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Mechanical Placement
• Barge transport for dredged material
• Capable of placing wide variety of material
• Multiple placement methods: barge, rehandling, conveyor, tremie
• GPS enabled for documentation of area coverage
Barge placement
Telebelt placement
Thin layer placement with rehandling bucket
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Hydraulic Placement
• Slurry transport via hydraulic pumps and pipeline
• Barges equipped with anchoring system and GPS
• Ideal for sand and finer material up to 1 inch in diameter
• Thin layer cover combines dredging and precision placement, restores marsh elevation
Hydraulic with diffuser screen
Hydraulic diffuser
Thin layer capping over marsh
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Sediment Dewatering
• Passive dewatering– Stockpiles, barge dewatering– Wick drains– Surcharging– Effectiveness varies with material type– Less certainty
• Geotubes (hydraulic dredging)– Contained passive dewatering– Need space and time– Used for beach nourishment, temporary berms,
contaminated sediment dewatering
• Active dewatering– Filter or belt press (mechanical or hydraulic
dredging)– Hydrocyclone for size separation– More certainty
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Empty Geotubes Prior to Filling
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Full Geotubes Releasing Water
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Excavating a Full Geotube
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Active Dewatering Equipment
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Hydrocyclone Size Separation
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Slurried dredge material
Contaminated fines and water
Washed sand
Hydrocyclone Size Separation (cont.)
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Treatment – Stabilization
• Adding lime/cement/other to
– Bind up water
– Reduce chemical leachability
– Increase strength
• Can be simpler than dewatering
• Typically used to address site stability or strength needs, or sediment contaminants
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Confined Disposal Facilities
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
CDF Design Guidance
• U.S. Army Corps of Engineers publications
– EM 1110-2-5025 Dredging and Dredged Material Disposal
– EM 1110-2-5027 Confined Disposal of Dredged Material
– Dredging Research Program (DRP)
– Dredging Operations and Environmental Research (DOER)
– EM 1110-2-1902 Slope Stability
Source: http://www.publications.usace.army.mil/USACEPublications/EngineerManuals.aspx
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
CDF Design Considerations
• Containment design – Static and seismic stability
– Contaminant mobility
• Size and capacity– Short-term bulking and settlement
– Long-term consolidation
– Ponding area to meet water quality criteria
• Pumping distance– Water content
• Site final use– Habitat
– Shoreline development
– Recreation
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Milwaukee Waterway NCDF and Habitat
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Milwaukee Waterway NCDF and Habitat
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Confined Aquatic Disposal
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Confined Aquatic Sites
• USACE Publications– EM 1110-2-5025 Dredging and
Dredged Material Disposal
– EM 1110-2-5027 Confined Disposal of Dredged Material
– DRP and DOER Reports
• USEPA– Ocean Disposal Manual
– CAD designs
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
CAD Design Considerations
• Submerged or emergent• Containment design
– Static and seismic stability
– Erosion protection
– Contaminant mobility
• Size and capacity– Short-term bulking and settlement
– Long-term consolidation
• Sustainability
• Pumping distance– Water content
• Site final use– Typically habitat function
– Navigation and anchoring restrictions
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
48
Place Contaminated Sediment in CAD
Port Hueneme Beneficial Use
Place CAD Clean Sediment as Beach Nourishment
CAD
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Port Hueneme CAD Cross-section
-85’ MLLW
-56’ MLLW
-46’ MLLWClean Cap
Contaminated Sediments
-43’ MLLW
Note:MLLW = mean lower low water
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Port Hueneme, USACE, U.S. Navy
Port Hueneme – Barge Placement
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Port Hueneme – Barge Placement
Port Hueneme, USACE, U.S. Navy
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Beach Nourishmentand Habitat Restoration
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Other Beneficial Uses
• Beach nourishment
• Agriculture and products– Topsoil– Aquaculture
• Berms– Stable and feeder
• Habitat restoration
• Land improvement
• Marsh and intertidal habitat
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Parallel Geotextile Tubes in Perimeter Dikes
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Deer Island Marsh Creation
• Design elements
– 7- to 8-foot-high dike
– Easterly wing dike
– Flash board riser weirs
– Offset to provide bayou
• Dredged material from Biloxi Lateral Channel
• Approximately 40 acres were filled with 365,000 cy of sediment
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Enhancing Existing Marsh
Illustration of conceptual model for marsh recovery after thin-layer disposal
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Case Study: GP Log Pond
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
GP Log Pond Remediation and Habitat Creation
• Cost-effective sediment remediation alternative
• Cap in place >130,000 cy industrial waste product
• Beneficial reuse of 43,000 cy of dredged material
• Restoration of 5.6 acres of intertidal and shallow subtidal habitat
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
GP Log Pond
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Wave Modeling for Cap Stability
Whatcom Waterway
GP Log Pond
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Habitat Creation Criteria
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Key Design Considerations• Dredge material as habitat cap
– Swinomish Channel and Squalicum Harbor combined dredge materials
– Fine to medium sand + slightly sandy, clayey silt (MH)
• Coastal stability and sea level rise– Shoreline and cap armoring
• Long-term consolidation– Habitat elevations for eelgrass
• Contaminant mobility– Groundwater transport
– Contaminant isolation
• Mechanical methods– Limit water quality impacts
– Placement precision
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Predictive Modeling and Design Solutions for Beneficial Use of Dredged Material
Questions?