advanced technology for cyclones storm damage risk

Advanced Technology for Cyclones Storm Damage Risk Reduction Systems and Flood

Protection Levees

Amir Shahkolahi

Global Synthetics, Brisbane, AustraliaE-mail: [email protected]

Drew Loizeaux

Propex, USAE-mail: [email protected]

mailto:[email protected]

Flood Protection Levees:

Flood Protection Levees:OVERTOPPING OF THE L-550 LEVEE IN ATCHISON COUNTY, MISSOURI, DURING A MISSOURI RIVER FLOOD, JUNE 2011 (SOURCE: USACE).

Flood Protection Levees Armouring:• Armouring will increase resiliency against severe wave overtopping caused by

hurricane storm surges.

• Armouring will help reduce scour and protect the integrity of the flood defence structure when confronted with severe wave overtopping.

What is the best Armouring technique?

Armouring Types:• · Grass

• · Soil Cement Treatments

• · Erosion Control Blankets

• · Turn Reinforcement Mat

• · Rock Riprap

• · Gabions

• · Concrete Slope Paving

• · Open Stone Asphalt

• · Fabric Formed Concrete

• · Articulated Concrete Block (ACB)

Research Background:• In 2005: Cyclone/Hurricane Katrina,

Southeast Louisiana, Category 5.

• Approximately 80% of New Orleans was flooded.

• Flood depths exceeding 15 feet in many areas.

• Surge and waves caused 50 major levee

breaches

• Thirty-four of the city's pumping stations were

damaged,

• Rainfall: 14 inches in a 24-hour period.

• More than 1,500 lives were lost.

Research Background:

Cyclone/Hurricane Katrina

Research Background• In 2006: US Army Corps of Engineers (USACE) started the $14.5 Billion program,

“Hurricane and Storm Damage Risk Reduction System (HSDRRS)”

Focus:

Strengthening levees, floodwalls, gated structures and pump stations

Goal:

What is the most cost effective, environmentally friendly and high performance solution

Research Background• In 2005-2006: USACE used ArmrMax® Engineered Earth Armouring Solution

(EEAS) on Penn flood levee as the armouring system as a trial.

•What is ArmorMax® EEAS?

ArmorMax® Engineered Earth Armouring Solution (EEAS):

• Combination of:

Engineered Earth Anchors (EEA)

High Performance Turf Reinforcement Mat (HPTRM)


• Installation process

ArmorMax® EEAS

Finished Installation 4 Years

pg 16

ArmorMax® EEAS

ArmorMax® on Penn Levee:

Research Background• In 2008:

Category 3 Cyclone, winds of 208 km/h

What happened to Penn levee

with ArmorMax® EEAS?

Research Background

• No damage and erosion occurred

• ArmorMax® EEAS could protect the levee

• As a results, USACE decided to investigate this system in details and in comparison to other systems

Research details:

Two phases:Phase 1: Full-scale field test: To investigate the requirements of HPTRMs to withstand installation and maintenance (e.g. mowing) loads

Phase 2: Full Scale Overtopping Test: To investigate the performance of these systems under real overtopping condition

Phase 1: Full-scale field test • 1.5km of levees were

used

Phase 1: Full-scale field test

Phase 1: Full-scale field test result• HPTRM minimum requirements:

Property Test Method Average Roll Value

Mass per unit area ASTM D6566 ≥ 288 g/m2

Thickness ASTM D6525 ≥ 7.6 mm

Light Penetration (% passing) ASTM D6567 ≤ 45%

Tensile Strength ASTM D6818 ≥ 45 kN/m

Elongation ASTM D6818 ≤ 65%

Resiliency ASTM D6524 ≥ 70%

UV Resistance @2500 hrs ASTM D4355 ≥ 80%

Phase 2: Full-scale Overtopping Test • Colorado State University (CSU)

• Can simulate average overtopping discharges as high as 370 l/s per m

Phase 2: Full-scale Overtopping Test

HPTRM Opening/Light Penetration

90% opening 35% opening 25% opening 10% opening

HPTRM Opening/Light Penetration

HPTRMs with smaller percent light penetration (to a minimum necessary value) improved vegetation performance in hydraulic testing

pg 30

ArmorMax® Armouring System for Levees – Installation phase

pg 31

ArmorMax® Armouring System for Levees – Vegetated

Conclusion:• HPTRM reinforced vegetation systems perform as well as if not better than the rock

armour protection layers for hydraulic applications such as storm water channels and flood protection levees.

• A HPTRM solution is a more cost effective and environmentally friendly solution than traditional hard armour solutions.

• Engineered Earth Armouring Solution (EEAS) which consist of a High Performance Turf Reinforcement Mat (HPTRM) and Engineered Earth Anchors (EEAs) can increase the safety factor of the armouring system against hydraulic forces and also provide slope surface stability.

Conclusion:• Tensile strength is the key component for durability and long-term performance of

HPTRMs, especially for storm water and flood protection applications.

• FHWA minimum requirement for tensile strength of HPTRMs is 45 kN/m.

• UV resistance is another key parameter for the durability of HPTRMs.

• HPTRMs with smaller percent light penetration, improves the vegetation performance in hydraulic testing whether established from seed or turf.

• Light penetration of 10% as minimum and 50% as maximum is suggested for HPTRMs to provide the required short term and long-term performance.

THANK YOU !

advanced technology for cyclones storm damage risk

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