US Army Corps of Engineers Engineer Research & Development Center, Coastal and Hydraulics Laboratory...

US Army Corpsof Engineers

Engineer Research & Development Center, Coastal and Hydraulics Laboratory Joan Pope


Engineer Research & Development Center, Coastal and Hydraulics Laboratory

Goals of the CEM

• Expand, update, and replace the SPM

• Practical and easy to use

• State-of-the-art technical guidance document for coastal flooding, navigation, and shore protection projects

• Include basic principles of coastal processes

• Include methods for computing coastal planning, design, construction, and maintenance parameters

• Integrate computer-based and field data collection tools with the fundamentals of good engineering practices

• “…..written at a level suitable for USACE District, BS-level engineering graduate who has no advanced academic training in coastal engineering.”

• Expand, update, and replace the SPM

• Practical and easy to use

• State-of-the-art technical guidance document for coastal flooding, navigation, and shore protection projects

• Include basic principles of coastal processes

• Include methods for computing coastal planning, design, construction, and maintenance parameters

• Integrate computer-based and field data collection tools with the fundamentals of good engineering practices

• “…..written at a level suitable for USACE District, BS-level engineering graduate who has no advanced academic training in coastal engineering.”



What’s new?

• Spectral waves• Harbor and navigation design• Coastal geology• Dredging and disposal• Sediment prediction and management• Structure inspection, repair, and rehab• Wetlands and protected locations• Environmental enhancements• Monitoring and maintenance• Risk and uncertainty• Numerical simulation and modeling technology• Beach fill design• Functional design emphasis• Project development process, ………etc…….etc…..etc.

• Spectral waves• Harbor and navigation design• Coastal geology• Dredging and disposal• Sediment prediction and management• Structure inspection, repair, and rehab• Wetlands and protected locations• Environmental enhancements• Monitoring and maintenance• Risk and uncertainty• Numerical simulation and modeling technology• Beach fill design• Functional design emphasis• Project development process, ………etc…….etc…..etc.



http://bigfoot.wes.army.mil/cem001.html



• PART I: Introduction

• PART II: Coastal Hydrodynamics

• PART III: Coastal Sediment Processes

• PART IV: Coastal Geology

• PART V: Coastal Project Planning & Design

• PART VI: Design of Coastal Project Elements

• PART I: Introduction

• PART II: Coastal Hydrodynamics

• PART III: Coastal Sediment Processes

• PART IV: Coastal Geology

• PART V: Coastal Project Planning & Design

• PART VI: Design of Coastal Project Elements

OUTLINE



• Water wave mechanics• Meteorology and wave climate• Estimation of nearshore waves• Surf zone hydrodynamics• Water levels and long waves• Hydrodynamics of tidal inlets• Harbor Hydrodynamics• Hydrodynamic analysis and

design conditions

Water Wave Mechanics Part II-1

• Linear Wave Principles

• Other Wave Theories

• Korteweg and deVries and Boussinesq

• Fourier Approximation – Fenton’s theory

• Irregular Wave Analysis

• Directional Wave Spectra

• Random Wave Simulation

• Linear Wave Principles

• Other Wave Theories

• Korteweg and deVries and Boussinesq

• Fourier Approximation – Fenton’s theory

• Irregular Wave Analysis

• Directional Wave Spectra

• Random Wave Simulation



Meteorology and Wave Climate Part II-2

• Estimating Marine and Coastal Winds

• No significant changes, as per SPM 1984

• Winds from near-surface observations

• Winds from pressure fields and weather maps

• Modification for

– Level

– Duration

– Overland or overwater

– Air-sea temperature stability

• Estimating Marine and Coastal Winds

• No significant changes, as per SPM 1984

• Winds from near-surface observations

• Winds from pressure fields and weather maps

• Modification for

– Level

– Duration

– Overland or overwater

– Air-sea temperature stability



ESTIMATION OF NEARSHORE WAVES Part II-3

Refraction, diffraction, shoaling, breaking, dissipation due to friction, dissipation due to percolation, additional growth due to winds, wave-current interactions, wave-wave interactions



Three Classic Cases of Wave Transformation

1. A large storm generates deepwater waves that propagate across shallow water while the waves continue to grow due to wind

2. A large storm generates waves in a remote area and as they cross shallow water with negligible wind they propagate to the site as swell

3. Wind blows over a shallow water fetch and as the waves grow they interact with the bottom

• Types 1 and 3 require numerical model whereas 2 can be approximated using a monochromatic wave

1. A large storm generates deepwater waves that propagate across shallow water while the waves continue to grow due to wind

2. A large storm generates waves in a remote area and as they cross shallow water with negligible wind they propagate to the site as swell

3. Wind blows over a shallow water fetch and as the waves grow they interact with the bottom

• Types 1 and 3 require numerical model whereas 2 can be approximated using a monochromatic wave



•Based on Mild-Slope equation•Includes wave breaking (first occurrence)•Consistent with theories used in calculation of longshore sediment transport and shoreline change

•Suitable for regions: 10’s of km •Grid resolution: fractions of wave lengths (1/10 or smaller)•Solution technique: finite difference•Neglects reflections off of structures and rapid changes in bathymetry

•Output gives wave height and direction variability with changing water levels

RCPWAVE



•Based on Mild Slope – wave current model (Kirby (1984))•Simple breaking criteria (H = 0.78 d)•Includes damping due to Bottom boundary layer; Sand-bed percolation; Turbulent bottom boundary layer•Wave non-linearity•Smooth correction to Stokes for shallow water•Numerical noise filter

•Suitable for regions: 10’s of km •Grid resolution: 5 to 6 grid points per wavelength (optimum)•Solution technique: finite difference•Neglects reflections off of structures and rapid changes in bathymetry

REFDIF

•Steady state Spectral Model•Solves complete radiative transfer equation and includes

•Propagation Effects – refraction, diffraction, shoaling, wave-current•Source term effects – breaking, wind, wave-wave

•Deals with stochastic wave components so suitable over very large distances•Can also incorporate phase information over short distances near discontinuities such as structures•Assumptions

•Nearshore transformations dominated by conservative processes (refraction, shoaling and diffraction)•Predictions based on uni-directional monochromatic wave theories•Can provide solutions equivalent to behaviour of directional spectra

STWAVE



Advanced Model Limitations

Almost all of these models are regularly used to simulate conditionsoutside a strict interpretation of the limits, with the results ofteneffectively accurate

CEM specified Major Limitations

RCPWAVE – inaccurate for wave crossing behind shoals or in the vicinity of structures. Wave approach not too OBLIQUE

REFDIF – should not be used with highly oblique waves

STWAVE – under-represent wave focusing for narrow swell



SURF ZONE HYDRODYNAMICS Part II-4

SURF ZONE HYDRODYNAMICS Part II-4Breaker Criteria – Irregular Waves

H rms = 0.42 d

or

Hmo = 0.6 d



•Water Surface Elevation Datum NEW

•Seiches - as in SPM 84

•Modeling of Long Wave Hydrodynamics NEW•Physical Models•Numerical Models (ADCIRC)

Water Levels and Long Waves Part II-5



Hydrodynamic Analysis and Design Part II-8

•Analysis of Key Meteorological and Hydrodynamic Processes

•Extreme wave analysis•Storms•Persistence•Long Waves•Water Level Climate



• Sediment Properties

• Longshore Transport

• Cross-shore Transport

• Wind-blown Transport

• Cohesive shores

• Outside the Surf Zone (Shore-face)



• Terminology

• Environments

• Classification and Morphology

• Morphodynamics

How the CEM will be used…

(Part V)Problem IdentificationEngineering ProcessAlternative SolutionsSite Characterization

Design ConditionsProject Development

Part II – HydrodynamicsPart III - SedimentsPart IV - Geology

Part VI Design ComponentsStructural Elements

MaterialsConstruction

O&M



Engineering Parts V and VI

• Planning and design process• Problem definitions• Site characterization and design conditions• Functional performance• Risk and uncertainty• Empirical design techniques• Analytical procedures per design element• Case examples

• Planning and design process• Problem definitions• Site characterization and design conditions• Functional performance• Risk and uncertainty• Empirical design techniques• Analytical procedures per design element• Case examples

Include:



• Planning & Design Process

• Site Characterization

• Shore Protection Projects

• Beach Fill Design

• Navigation Projects

• Inlets/Harbors

• Environmental Enhancement

• Federal Role in Hazard Mitigation



Six Major Planning Steps

Generic Design Chart

Planning Coordination Requirements

Design Constraints

Data Needs & Sources

Part V.1 – Planning and Design Process

The process of developing a coastal project must be iterative to ensure that the final product is optimum from both the technical and economic viewpoints acceptable to the various levels of

decision makers and all project partners.



Getting Started

• “What is the problem?”***

To achieve a successful coastal project plan and design requires that the engineer must start with a completely open mind, one without preconceived notions of the ultimate solution or a specific solution to advocate.

***“What is the project trying to accomplish?”(Quantify expectations!)

CP Module

EnvironmentalEconomic, Political,AestheticConstraints

Project Need

Project Problem Statement

Quantify w/o Project Condition

Simple Functional Analysis and Identification of Alternatives

Did You Fulfill All of Problem Statement?

Is Federal Participation Justified?

Is the Problem Statement Still Valid

Economics

AbandonProject

ModifyProjectProblemStatement

Select Alternative

Exit

No

No

No

No

Yes

Yes

CP Module

Damages

Yes

Yes

Yes

Generic Project Development Chart



Non-Structural Breakwater OtherSeawall

Dredging, etc. Do Nothing

Environmental and Economic Constraints

Select/Modify Functional Design

CP Module Test Functional Design

ModifyFunctional Design?

Is Functional Design OK?

Continue to Figure V-2-2



Design Constraints

1. Scientific and Engineering Understanding of Nature

The CEM emphasizes the understanding and ability to analytically and numerically model nature.

2. Economics

3. Environmental

4. Institutional, Political (Social), Legal

5. Aesthetics



Coastal Process Module, is defined as a repository of physical data and analysis tools relevant to the coastal problem. Wind, waves, currents, water levels, bathymetry, geomorphology, stratigraphy, sediment characteristics, sediment transport processes, etc. and the analysis tools (mainly numerical models) make up the CP Module.

A fully 3D, dynamic model to simulate coastal processes at different scales for different settings does not exist.

The “CP Module”

GENESIS

ADCIRC

SBEACH

STWAVE

SBAS

ETC.



Costs and Benefits

• Costs• Initial Costs• Maintenance Costs• Alteration/Removal

Costs• Total, Life-Cycle Cost• Design Life• Interest Rate• Damage• Failure• Balanced Design

• Costs• Initial Costs• Maintenance Costs• Alteration/Removal

Costs• Total, Life-Cycle Cost• Design Life• Interest Rate• Damage• Failure• Balanced Design

• Storm damage reduction & mitigation

• Ecosystems restoration.• Recreation and tourism

benefits • Waterfront property

(greater value and generates higher tax revenue).

• Coastal, beach related travel and tourism industry.

• Storm damage reduction & mitigation

• Ecosystems restoration.• Recreation and tourism

benefits • Waterfront property

(greater value and generates higher tax revenue).

• Coastal, beach related travel and tourism industry.



Storm Damage Reduction Benefits Methodology

1. Inventory structures.

2.Calculate depreciated replacement cost of the structures and content value.

3.Obtain the water level, storm frequency-of-occurrence data for the site and accompanying wave and shoreline erosion data.

4.Obtain and run storm damage calculation models.

5.Apply the models for without project conditions and for considered alternatives and sub-alternatives.



Sea Level Rise

• Over the last 100 years – 30 cm (3mm / yr) on the East Coast and 11 cm (1.1mm / yr) along the West Coast.

• Gulf of Mexico coast is high variable – 100 cm in the Mississippi delta plain to 20 cm along Florida’s West Coast.

• Statistics related to and impact of sea level rise are debated regularly in scientific circles.

• Existing rates of mean sea level rise have not been a severe economic constraint in shore protection design.

• Anthropogenic effects (ie; jettied tidal inlets) causing downdrift, beach erosion have resulted in larger impacts.

• Long-term, relative changes in sea level can be incorporated into storm surge analysis.



Data Needed Best Source(s) Alternate Sources

Site map/real estate Recent survey • Town maps• USGS• Digitized aerial

photographs

Site topography & bathymetry

USACE acoustic surveysSHOALSLIDAR

NOAA chartsContractor Surveys

Directional Wave Statistics (height, period & direction)

Directional Wave Gage • WIS hindcast• Wave hindcast using

wind statistics

Data Needs and Sources

…etc.



APPROACHClass

Type

Geometry(Configuration)orLocation

ConstructionMaterial

(A) CHANGES TO THE NATURAL, PHYSICAL SYSTEM

2. Beach Stabilization Structures & Facilities

Breakwaters GroinsSills&(Vegetation)

GroundwaterDrainage

Headland

Detached

Single

System

Tuned

Shoreline

Normal

Angled

Single

System

Notched

Permeable

AdjustableShaped (T or L)

Shoreline

Submerged

Perched beach(Submerged Aquatic Vegetation)

Beach drain

Bluff dewatering

Interior drainage

System of pipes,pumps with sumps

Rock

Precast concrete units

Sheet-pile (steel, timber, etc.)

Geotextiles bags



ElevatedStructures

Raise Grade

Sandbags

Flow Diversion

Setbacks

Land userestrictions

Public Lands(Institutional)

Individuals

Communities

Infrastructure

Move Structures

Single-Familyhomes ontimber piles

APPROACH

Class

Type

Geometry(Configuration)orLocation

ConstructionMaterial

(A) CHANGES IN MAN’S SYSTEM

4. Adaptation & Accommodation

Flood Proofing Zoning Retreat



• Types & Functions of Structures

• Site Specific Conditions

• Materials & Construction

• Fundamentals

• Reliability

• Case Examples

• Repair/Rehab & Modification



Fundamentals of Design Part VI-5-2

• Wave Runup and Overtopping

• Wave Reflection and Transmission



Effect of Permeability



Surf Similarity Parameter

Wave Runup- Smooth Impermeable Slopes

r - Influence of surface

roughness

b - Influence of fronting berm

h - Influence of shallow water

- Influence of approaching

wave angle



Runup on Rock Armored Slopes

Impermeable Rock Slopes

Permeable Rock Slopes

Coefficients



Wave Overtopping

• Occurs where the highest runup levels exceed the freeboard

• Unevenly distributed in space and time

• Usually expressed as time-averaged overtopping discharge

• Discharge from a single wave can be 100 times average

Definition of freeboard

Wave Overtopping...



Wave Reflection

Structure a b

Seelig Equation

With



Wave Transmission

Transmission Coefficient



FORMS OF RELEASE

• USACE ENGINEERING MANUAL– Official EM on Corps website– Non-interactive PDF version– Currently older-versions of Parts III and IV only

• INTER-ACTIVE ELECTRONIC VERSION – Developed by non-government partner (Veri-tech) as

commercial product – Parts I-IV newly released

• PUBLISHED HARDCOPY– Government Printing Office– Entire document to be released at one time (2002)– Limited updates

• USACE ENGINEERING MANUAL– Official EM on Corps website– Non-interactive PDF version– Currently older-versions of Parts III and IV only

• INTER-ACTIVE ELECTRONIC VERSION – Developed by non-government partner (Veri-tech) as

commercial product – Parts I-IV newly released

• PUBLISHED HARDCOPY– Government Printing Office– Entire document to be released at one time (2002)– Limited updates



STATUS

• PART I: Introduction ON WEB– Includes definitions, history, diversity

• PART 2: HYDRODYNAMICS ON WEB– EC-1110-2-289 Released 9/96 as hardcopy

• PART 3: SEDIMENT PROCESSES– EC-1110-2-292 Released 3/98 on web as PDF file– Revised and in final format– Minor figure improvements

• PART 4: GEOLOGY ON WEB– EM 1110-2-1810 released 1/95 as hardcopy

• PART I: Introduction ON WEB– Includes definitions, history, diversity

• PART 2: HYDRODYNAMICS ON WEB– EC-1110-2-289 Released 9/96 as hardcopy

• PART 3: SEDIMENT PROCESSES– EC-1110-2-292 Released 3/98 on web as PDF file– Revised and in final format– Minor figure improvements

• PART 4: GEOLOGY ON WEB– EM 1110-2-1810 released 1/95 as hardcopy

Glossary of Terms –in draft form, under review



STATUS (continuing)

• PART V: Project Planning and Design

– DONE: CH 1, 2, 3, 4, 5 & 7

– FINAL REVISIONS

• 6 (Inlets)

• 8 (Federal Requirements)

• PART V: Project Planning and Design

– DONE: CH 1, 2, 3, 4, 5 & 7

– FINAL REVISIONS

• 6 (Inlets)

• 8 (Federal Requirements)

• PART VI: Design of Project Elements

– DONE: CH 2, 3, 4, & 5

– FINAL REVISIONS

• 6 (Risk/Reliability)

– SOME WRITING LEFT

• 7 (Case Examples)

• 8 (Repair & Rehab)

• 1 (Intro)

• PART VI: Design of Project Elements

– DONE: CH 2, 3, 4, & 5

– FINAL REVISIONS

• 6 (Risk/Reliability)

– SOME WRITING LEFT

• 7 (Case Examples)

• 8 (Repair & Rehab)

• 1 (Intro)



FUTURE INITATIVES

• FINISH THE darn THING!

• RELEASE USACE ON-LINE VERSION

• PUBLISH GPO HARD-COPY VERSION

• CONTINUING TECHNICAL SUPPORT AND UPDATES

• COORDINATION WITH CRDA PARTNER

• USER WORKSHOPS/CLASSES

• EDITORICAL CORRECTIONS

• INCORPORATE R&D ADVANCES

• APPENDICES & NEW SECTIONS AS REQUIRED

• FINISH THE darn THING!

• RELEASE USACE ON-LINE VERSION

• PUBLISH GPO HARD-COPY VERSION

• CONTINUING TECHNICAL SUPPORT AND UPDATES

• COORDINATION WITH CRDA PARTNER

• USER WORKSHOPS/CLASSES

• EDITORICAL CORRECTIONS

• INCORPORATE R&D ADVANCES

• APPENDICES & NEW SECTIONS AS REQUIRED

….the end….and

..the beginning.

US Army Corps of Engineers Engineer Research & Development Center, Coastal and Hydraulics Laboratory...

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