New Orleans Levee Failure

Physical Modeling

Mateo ArimanyAlbert Bleakley

February 2010

Outline Background - Bleakley

• Geography• Outfall canals• Levees

Hurricane Katrina - Bleakley• Effects• Failures

Investigation - Arimany• Borings/CPT/soil testing• Centrifuge modeling

Lessons learned - Bleakley

Legend Federal Federal Non-COE

Non-Federal

5 Parishes350 Miles of Levee/Floodwall73 Pumping Stations (Fed & Non-Fed)4 Gated Outlets

Background – Geography Orleans Area

6

1878

17TH

St.

Cana

l

NEWORLEANS

A

B

Lake Ponchartrain

MISS. R

Hurricane Betsy 1965

City of New Orleans

Ground Elevations

From Canal St. at Mississippi River

to theLakefront

Miss

issipp

iRi

ver B

ank

LakePontchartrain

Shore

NEWORLEANS

A

B

Lake Ponchartrain

MISS. R A

Project designflowline (18 feet)

Der

bign

y At

I-10

Espl

anad

e At

St. C

laud

e

Cana

l St

At R

iver

St L

ouis

Cath

edra

l

Gen

tilly

Blv

dAt

Alle

nD

illar

d U

niv

Cam

pus

St A

ntho

ny A

tFi

lmor

e Av

e

WAI

NRI

GH

T D

RAT

L. C

. SIM

ON

Uno

Sid

e O

fW

ainw

righ

t D

r

London Avenue Canal floodwallHURRICANE LEVEE / FLOODWALL (14.0 FEET)

30

20

10

0

-10

-20

30

20

10

0

-10

-20Elev

atio

ns In

Feet

Ngv

d

Floodwall AlongMississippi River

23 FT

New Orleans Topography

B

Hurricane KatrinaAug, 2005

One of America’s largest natural disasters Cat 5 less than 12 hrs before landfall 127 MPH wind at Louisiana landfall Maximum surge of 28 to 30 feet along

Mississippi coast City of New Orleans flooded

Cat 4 less than 12 hrs before landfall 175 MPH max sustained winds in Gulf of

Mexico 120 MPH max sustained winds at landfall Cat 3 strength at landfall

9

Hurricane RitaSep 24, 2005

Hurricane RitaSep, 2005

10

8 to 15 feet

10 to 13 feet

12 to 15 feet

9 to 11 feet

High: 15 Ft.

Low: 0 Ft.

Design Failure Breach Locations

New OrleansMaximum Flooding Depth

As of 4 NOV 05

Investigation

Investigation

Investigation

Physical Modeling Team

Prof Tarek H. Abdoun, PhDProf Thomas F. Zimmie, PhD, PEInthuorn Sasanakul, PhDJavier Ubilla, MSMarcelo Gonzalez, MSHassan RadwanAlex SankovichDominic Moffitt

Michael K. Sharp, PhD, PEWipawi Vanadit-Ellis, MSWayne HodoHenry BlakeDavid DailyDave Carnell

R. Scott Steedman, PhD FREng FICEKevin Stone, PhD

Prof Dr Ir Frans BarendsPaul Schaminée , MScAdam Bezuijen, MSc

London North Model

London South Model

Orleans South Model

ERDC Centrifuge

RPI Centrifuge

Test Video

London South – sand foundation

Sand layer pile tip local shear failure

London South – sand foundation

limiting shear force on underside of peat

limiting passive resistance in sandPivot

hydrostatic force

Wall

Swampy Marsh

‘crumple zone’

rising water pressure decreases vertical effective stress

Typical cross section

London South – sand foundation

17th Street – clay foundation

17th Street – clay foundation

Top of clay layer general shear failure

Pivot

Key findings

2. The centrifuge models were consistent and useful to determine mechanisms in all cases studied.

1. Wall movement was in all cases sufficient to form a crack in front of the wall.

3. Performance of all levee sections studied 17th Street, London Avenue and Orleans was consistent with field observations and numerical models.

Swampy Marsh

4. Uplift of swampy marsh leads to unloading.

Lessons Learned - System Improvements:

62

Permanent Pump

Stations

Repair Correct Floodwall DeficienciesImprove

Storm Proof Pump

Stations

Surge Barrier

IHNC Lake Borgne

64

Summary Background - Bleakley

• Geography• Outfall canals• Levees

Hurricane Katrina - Bleakley• Effects• Failures

Investigation - Arimany• Borings/CPT/soil testing• Centrifuge modeling

Lessons learned - Bleakley

Questions?