rolled sediment revetment

Replacing Hard Armor with Reinforced Vegetative Solutions Presented by Rob Lawson, CPESC

North Atlantic Region Manager

Rolled Sediment Revetment

Ease of Access – Owner’s Expectations

Overkill?

How do you define Permissible Shear Stress

▪ Shear Stress or “tractive force” is the energy exerted on the lining of the channel or slope

▪ Measured in pounds per square foot (lbs./ft2)

▪ What affects Shear Stress:

▪ Velocity

▪ Depth of flow

▪ Gradient

▪ ASTM industry testing, FHWA, ECTC and NTPEP use this methodology

▪ What is the threshold:

o Industry product testing performed uses a half inch of soil loss as failure criteria

o Once failure has been reached, that will be the permissible shear value allowed for that product

Composite-TRMs

3-D permanent matting structure with fiber matrix

▪ Immediate erosion control

▪ Surface applied: No Soil Filling

▪ Mulching aspect enhances vegetation establishment

▪ Permanently reinforces & anchors roots & stems

▪ Enables vegetation use in severe applications

▪ Substantial cost savings compared to riprap or concrete

Composite Turf Reinforcement Mats

EPA Tech Sheet - Turf Reinforcement Mats (TRMs)

TRMS are classified as a “soft engineering practice,” in contrast to concrete and riprap, which they may replace in certain erosion control situations.

TRMS can incorporate natural fiber materials to assist in establishing vegetation. However, the permanent reinforcement structure of TRMs is composed of entirely non-degradable synthetic materials.

Rip Rap Issues

• Thermal Pollution

• Large Stone – Big Equipment

• Availability

• Installation

• Safety/Liability

• Cost

• Maintenance

• OWNER EXPECTATIONS*Aesthetics, access, etc.

August 2, 2016

We wanted to let you know of changes coming from the U. S. Army Corps of Engineers

(USACE) that could mean big differences in the way Americans protect streambanks and

shorelines from the erosive forces of water. The USACE is trying to encourage everyone to

reduce the amount of Hard Armor (riprap, concrete, and bulkheads) previously used as erosion

control Best Management Practices (BMPs). Hard Armor erosion control measures have not

proven to be permanent fixes for erosion problems around streams, lakes, and the ocean/land

interface. They feel that the only permanent erosion control BMP utilizes vegetation.

The Corps seems to understand there are highly erodible areas where the ocean and land

meet (beaches, bluffs, or tidal areas) may still require use of hard armor (riprap) combined with

vegetation to control erosion. However, you will find soon that the main recommended

stabilization measure favored by the USACE will be vegetation. The Corps will increase support

requirements for what they call Living Islands or Living Shorelines. The Alabama

Department of Environmental Management (ADEM) currently regulates Living Shorelines and

Living Islands under the General Permit ALG10-2011. However, the proposed USACE 2017

Construction General Permit (CGP), the Corps is expanding their emphasis on the use of

“Green Bioengineering” erosion control requirements.

This could be the dawn of a new era for more natural ways to control erosion called living

shorelines or “Green Bioengineering”. The U. S. Army Corps of Engineers (USACE) has

released for public review its list of Proposed Nationwide Permits that will renew 50-Nationwide

Permits for work in wetlands and other waters that are generally regulated by Section 4040 of

the Clean Water Act and/or Section 10of the Rivers and Harbors act of 1899. The USACE also

proposes to issue two Nationwide Permits including a proposed permit that specifically

addresses the construction and maintaining Living Shorelines.

Nationwide Permit B is the Corps’ first living shorelines permit. Living shoreline projects use

various structural and organic materials, such a plants, submerged aquatic vegetation, oyster

shells and stone. For years, permitting guidelines for living shorelines simply were folded into

other rules governing shoreline stabilization methods under Permit 13.

The Corps issues nationwide permits for a whole host of activities covered by the federal Clean

Water and Rivers and Harbors acts. The Corps streamlined review of applications for such

permits because the activities will have minimal effects on the environment.

The new living shoreline permit has been a long time coming, proponents say, as research has

mounted in support of the practical and environmental benefits of this shoreline erosion control

technique. Permit B further legitimizes living shorelines, raising awareness of this shore

stabilization alternative at the federal level.

More importantly, proponents say, the new permit will help speed up the permitting process for

living “vegetated” shorelines and should more evenly balance agency review times for living

shorelines and hardened erosion control structures, such as bulkheads.

The Corps cannot mandate one specific approach to shoreline stabilization, but the agency

does acknowledge the benefits of living shorelines. “We are trying to provide as much

▪ Permanent matting structure reinforces vegetation

▪ Fiber matrix provides immediate erosion control and assists in seed germination/growth

▪ Designed for severe slopes &

drainage channels

Composite Turf Reinforcement Mat (C-TRM)

High Strength Top

Net

3-D Corrugated Center

Net

Straw/Coconut Matrix

Material

High Strength Bottom

Net

Slopes Channels

Straw/coconut fibers provide 2 years of immediate erosion control and mulching

Permissible Shear Stress Values =

Phase 1: Un-vegetated

3.0 lbs/ft2 (144 Pa)

Phase 2: Partially Vegetated

8.0 lbs/ft2 (384 Pa)

Phase 3: Fully Vegetated

10.0 lbs/ft2 (480 Pa)

Comparable to 24 in Rock Rip Rap!

C-TRM Performance

C-TRM Ditches / Slopes

▪ 100% Coconut fiber matrix

▪ Field performance widely documented

▪ Protects soil, seed & root systems from flowing water

C-TRM

Super High Strength

Top Net

3-D Corrugated Center

Net

Coconut Fiber Matrix

Material

Super High Strength

Bottom Net

Slopes

Channels

Shorelines

▪ Coconut Fibers Provide 3 Years of Immediate Erosion Control and Mulching

C-TRM Performance


Phase 1 Un-Vegetated3.2 lbs/ft² (153 Pa)

Phase 2: Partially Vegetated10 lbs/ft² (480 Pa)

Phase 3: Fully Vegetated12 lbs/ft² (576 Pa)

Comparable to 30 in Rock Rip Rap!

C-TRM Slope / Channel

C-TRM Shore Line

Polypropylene Matrix Increases Permanent Vegetation Reinforcement

▪ Excellent for shorelines

▪ Replacement for rock and concreteUltra-High Strength

Top Net

3-D Corrugated

Center Net

Polypropylene

Matrix Material

Ultra-High Strength

Bottom Net

Slopes

Channels

Shorelines

Synthetic Composite TRM

Permanent erosion control and mulching, and extended unvegetatedprotection


Phase 1: Un-vegetated4.0 lbs/ft² (191 Pa)

Phase 2: Partially Vegetated12 lbs/ft² (574 Pa)

Phase 3: Fully Vegetated14 lbs/ft² (672 Pa)

Comparable to 30 in Rock Rip Rap and some concrete applications!

Synthetic C-TRM Performance

Synthetic Composite TRM Waterways

Synthetic C-TRM Bank Protection

TRM Shear Stress Comparisons

FHWA Specifications

Product FHWA Category

Performance

Requirements

SC-CTRM Type 5. A & B 6 lbs/ft² (288 Pa)

C-CTRM Type 5 A, B & C 8 lbs/ft² (384 Pa)

Synthetic

C-TRMType 5 A, B & C 10 lbs/ft² (480 Pa)

713.18 Permanent Rolled Erosion Control Products

2

3

▪ 60% - 80% Cost Savings vs Rock Riprap (@ $36/sy installed)

▪ One 40 sy roll of Vmax can replace approx 40 tons of rock!

▪ Reduced Long-Term Maintenance

▪ Less Hazardous along Roadways and Pedestrian Areas

▪ Increased stormwater infiltration (LID bioswales/filter strips)

▪ Environmentally Friendly

▪ Ecologically Functional

Why use TRM reinforced vegetation instead of rock?

▪ Up to 60% Savings over rock riprap

▪ Less expensive to install than soil in-filled TRMs

Economic Benefits

Vanderburgh Co Fairgrounds, Evansville IN

2

7 Veterans Park – Talladega, Alabama

Extended-Term Biodegradable

C700BN• 700 gram coir jute netting

• C125BN sewn to bottom

• Cotton thread stitch

Chavis Park Mixture of Bio Solutions

Chavis Park Vegetated

Total cost for a Channel Requiring 30 inch D50 Rock RiprapChannel is 3 ft x 16 ft x 1000 ft

C350 30 inch Rock

Materials $7,800-9,900 $32,000

Labor $6,400-7,900 $21,300

Total Installed

Cost

$14,200-17,800

($8-10/yd²)

$53,300

($30/yd²)

POTENTIAL SAVINGS = $39,100

*Costs will vary depending on location

Economic Benefits

▪ Tested to greater than 5000 lbs/ft tensile strength

▪ Increased geotechnical stability for shallow-slope failures when used in conjunction with percussion driven earth anchors

▪ High durability for damage resistance to equipment, debris-laden and

severe flow conditions▪ Compact profile minimizes need for infill while retaining vegetation

structural support ▪ May not need soil infill due to a more open structure and less thickness

▪ Large-scale 3rd party channel testing conducted with results greater than 15

lbs/sf once vegetated▪ Color woven design, increases tensile retention and UV stability

High Performance (HP-TRM)

Soil/Seed Filled Vegetated Channel Testing at TRI

HPTRM Performance Testing

Soil/Seed Filled Vegetated Channel Testing at TRI

(15 lbs/sf maximum vegetated shear stress)

HPTRM Performance Testing

High-Performance TRMs Properties

“Pyramid” Design

Corrugated netCorrugated “Pyramid”

Roll Size 10 x 90 ft

(100 sy)11.5 x 78 ft

(100 sy)

Vegetated Shear StressASTM D6460

16 psf 15 psf

Vegetated VelocityASTM D6460

25 fps 20-25 fps

Tensile StrengthASTM D6818

3600 x 3800

lbs/ft

3800 x 5000

lbs/ft

UV stabilityASTM D

4355

>80% >80%

(@3000 hr) (@3000 hr)

ThicknessASTM D6525

0.40 in 0.35

(10.2 mm) (8.6 mm)

Mass/Unit AreaASTM D6566

14.7 oz/sy 11.29 oz/sy

(495 g/m2) (380 g/m2)

✓ Sod Overlay to reduce concern of mower interference

✓ Structure of Matrix provides greater frictional surface as sod underlay to keep sod firmly in place until root establishment

✓High compression strength to maintain three dimensionality and maximum root interaction and reinforcement when seed/soil-filled or overlaid with sod

HPTRM Sod Overlay

▪ High Risk projects / Catastrophic events

▪ Geotechnical stability on slopes

▪ Areas with heavy maintenance equipment

▪ High- tensile applications

▪ Examples

▪ Levees

▪ Canals

▪ River banks

▪ Spillways

▪ Steep Slopes

▪ High flow channels

HPTRM Applications

HPTRM InstallationPercussion Driven Earth Anchors

Anchor Installation Demonstration

▪ Start by Placing

Anchor on Tip of Drive Rod

▪ Position Anchor to

Designation Location

▪ Place Gas Driver on

Rod and Set Anchor

to Design Depth

▪ Remove Gas Driver

and Pull Drive Rod

Out

▪ Slide Anchor Cap to

Soil Surface

▪ Tighten Cable and Set Anchor

▪ Clip Extra Cable

HP-TRM Louisiana Levee Protection

HP-TRM Installation

4 month vegetated

➢Unique armoring solution that dramatically elevates the performance against scour. When used with a TRM underlayment, it allows for vegetation use in high scour areas where hard-armor was once the only viable option.

➢ Applications: Shoreline transition zones, channel bottoms, pipe outlets, and more.

Erosion Control Systems

Transition Mats

Channel Scour / Shoreline Protection

Channel Scour Erosion by Wave Action

Tansisition Mat System Applications

Tranisition Mat with TRM for “head-to-tail” drainage protection

◆ Culvert outlets/ pipe outfalls

◆ Curb outfalls/ down chutes from parking lots / steep slope drains

◆ Can utilize earth anchors for added pull-out strength

◆ Transition Mat with TRM or geotextile, can incorporate coir log

toe, and earth anchors

◆ Pond, lake, levee, canal, stream shorelines

◆ Spillway stabilization

Flexible

▪ Easy installation for maximum performance

▪ Earth anchors NOT required – high specific gravity

▪ Will not “float”

Features & Benefits

“Soft” vegetative green solution

▪ Requires no heavy equipment to install

▪ Easier maintenance

▪ Greater safety for vehicles and pedestrians

▪ Increased water filtration compared to rock or concrete

Features & Benefits

➢Shoreline, Channel, Culvert installation guides available

➢ Typically installed with Transition Mat with Stakes, staples, or earth anchors

➢Culvert designs

▪ Width = 3-4 times the pipe diameter

▪ Length = 4-5 times the pipe diameter

Installation

Transition Mat should typically be used in conjunction with a TRM when

▪ Used in high scour, high shear areas

▪ Using seed to vegetate

▪ Most applications

Transition Mat should typically NOT be used with a TRM when

▪ Sod is specified

▪ Moderate areas where an ECB is being used

▪ When the product is submerged with no vegetation (use a geotextile underneath)

Installation

Typical Scour Apron Installation

Transition Mat culvert project, installation through 4 weeks

Installation over seeded TRM / Installation over existing vegetation

Transition Mat placed over seeded TRM

Transition Mat placed over established vegetation

Outfall Application

Transition Mat outfall project, Installed per California Fish and Wildlife

Pipeline Site Drainage

ShoreMax mat channel project,

Center Point Wellhead, Louisiana

Estimated Cost Analysis

Reinforced Vegetated Design

- TRM lining entire channel ($4.00/sy)

- 6 panels Transition Mat ($125 / panel)

- 2 Crew members installing 25 sy/hr each

Hard Armor Design

- 6 in Rock Rip Rap ($35.0/delivered ton)

- 2 Crew members installing 25 sy/hr each

Cost Analysis

Total cost for a Channel Requiring 6 inch D50 Rock Riprap vs Reinforced

Vegetation System with TRM and Transition Mat

Channel is 10 ft x 300 ft

TRM with Transition Mat

Outlet

6 inch Rock

Materials (& Equip) $2188 $7110

Labor $287 $533

Total Installed Cost $2475 $7643

POTENTIAL SAVINGS = $5168 or 68% savings

*Costs will vary depending on location

Wire Fasteners

❖ 6 inch Circle Top Pins

❖ 6 inch V-Top Staples

❖ 6, 8, 10, & 12 inch U-staples

BioStakes, biodegradable plastic T-Staples

❖ 4 inch BioStakes

❖ 6 inch BioStakes

EcoStakes, wooden stakes

❖ 6 inch EcoStakes

❖ 12 inch EcoStakes

❖ 18 & 24 inch EcoStakes (used with Sediment Devices)

Installation Tools

Fastening Devices

EcoStakes

BioStakes

Wire Staples

Rebar Staples

Earth Anchors

Installation Tools

o 300 lb pullout strength

o 1100 lb pullout strength

1. Prepare the seedbed by raking, seeding and applying fertilizer

2. Use trenching procedures to secure terminal edges

3. Keep material in contact with the soil

4. Place staples in appropriate locations using specified staple pattern

5. Secure all product overlaps

6. Ensure seams are shingled to prevent undermining

Installation Guidelines for RECPs

1. Prepare Soil Bed

2. Anchor in leading edge

3. Unroll product

4. Staple using the

correct staple pattern

5. Shingle

overlaps and secure

Typical Installation Guidelines for RECPs


Slopes


Channels

Shoreline


◆ Software designs for the following applications

◆ Channels

◆ Slopes

◆ Vegetation Selection

◆ Spillways

◆ User-Defined Channels

◆ Outlet

◆ Drop Structure

◆ Mattress Channel

Design Software

Assists in selection of:

Temporary Erosion Protection

➢Rolled Erosion Control Products (RECPs)

➢Hydraulic Erosion Control Products (HECPs)

Permanent Erosion Protection

➢ Vegetation

➢Reinforced Vegetation

➢ (TRMs, Transitions mats)

Hard Armor

➢ (Marine Mattresses, rock riprap, concrete)

Design Software Features

Designing with Software Erosion Control Systems

▪ Soil loss calculations based on Revised Universal Soil Loss Equation

(RUSLE)

▪ RUSLE factors rainfall, slope length and grade, soil types, and cover

type.

▪ Failure based on tolerable soil loss limits

▪ Examine temporary blankets, permanent vegetation, & permanent

reinforced vegetation

▪ Analysis for United States, Canada, Australia, Japan, Latin America

and other countries

Slope Module Features

▪ Failure criteria based on permissible shear

▪ Facilitates use of 3 phase design analysis

▪ Accounts for differing vegetation growth habits and densities

▪ Accounts for differing soil types

▪ Analyzes channel bends and composite linings

▪ Analyze product performance with a wide range of vegetation types

Channel Module Features

▪ Analyzes shear force applied to a given channel lining

▪ A single performance value defines each specific channel liner’s performance

▪ Design methods are applicable under a wide range of channel configurations (i.e., trapezoidal, V-shaped)

▪ Determination of increased erosive forces in channel bends

Maximum Permissible Shear Stress Approach


“Design of Roadside Channels with Flexible Linings”

▪ Based on permissible shear stress procedures

▪ More concise design methodology than permissible velocity

▪ Procedures for designing all flexible channel liners

▪ Outlines methodology for designing vegetated channels

Federal Highway Administration’s Hydraulic Engineering Circular #15


USDA’s Agriculture Handbook 667

▪ Improved definition of vegetative cover (e.g. growth habit and density)

▪ enhanced definition of effective roughness

▪ better definition of cover provided by vegetation

▪ Determination of shear force penetrating vegetation

▪ Calculates shear stress acting on underlying soil

Refining Vegetative Channel Liner Design


Erosion Control Technology Council

• https://www.ectc.org/

• Industry Organization comprised of manufacturing professionals

• Product application tutorials and videos

• Product performance categories

• Questions & Answers

https://www.ectc.org/

QUIZ TIME!

8/12/2019 74

Summary Questions

1. Which product would be a permanent mat:- Straw/excelsior mat- Turf Reinforcement Mat- Straw/coconut mat- Coconut mat

2. Which statement best describes a Turf Reinforcement Mat:- Provides immediate erosion protection- Traps soil particles

- Extends the permissible shear stress limits of vegetation- All of the above

3. Does the USACE recognize green soft armor solution alternatives? Y/N

4. Which design parameter is the best determining factor for addressing erosion protection in

a channel:- Velocity- Gradient- Permissible shear stress- Width

Summary Questions continued

5. Can permanent Turf Reinforcement Mats have biodegradable components? Y/N

6. Which practice would be the most cost effective solution for a 24” pipe outfall:

▪ Rock rip rap

▪ Concrete

▪ Flexible transition mat

7. Is it possible to increase geotechnical stability for shallow-slope failures using TRMs used

in conjunction with percussion driven earth anchors? Y/N

8. Federal Highway Administration uses what hydraulic calculation in their Hydraulic

Engineering Circular #15 guidelines for channels?

▪ Independent laboratory testing

▪ Permissible shear stress

▪ Product material composition

▪ USDA Revised Universal Soil Loss Equation (RUSLE)

Thank You

Questions?

rolled sediment revetment

Documents