Technical Update on EM 1110-2-1913, Design and Construction of

Upcoming Changes for EM 1110-2-1913
D i
Design,
Construction,
C
i
and
d Evaluation
E l
i off Levees
Scott E. Shewbridge, PhD, PE, GE
National Technical Specialist
p
– Risk & Geotechnical Engineering
g
g
Risk Management Center, Denver
Michael Navin, PhD, PE
US Army Corps of Engineers, St. Louis District
Neil Schwanz,, PE
US Army Corps of Engineers, St. Paul District
Noah Vroman, PE
US Army Corps of Engineers, MVD Dam and
Levee Safetyy Production Center, Vicksburg
g
ASDSO 2015 Annual Conference
16 September 2015
Objective
 To provide an overview of the updates
being proposed for EM 1110-2-1913
Design Construction
Design,
Construction, and Evaluation of
Levees
2/81
Contents
 Introduction and overview of some
regional design differences
 Review of Chapters
 Questions and Discussion
3/81
Complaint About Old EM
“It’s
It s great if you are from the Mississippi
Rivers and Tributaries Project, but
th ’ nothing
there’s
thi about
b t th
the types
t
off levee
l
designs we do here in _____________.”
4/81
Primary Objectives
To update the USACE EM for Design,
Construction and Evaluation of Levees
► Compile
information on regional design
approaches and performance expectations
including operations, maintenance, floodfighting efforts and associated documentation
► Use risk-based potential failure modes to
establish design objectives and approaches
► Assess adequacy of traditional design with risk
analysis
l i methods
th d
5/81
EM Revision Team
1
2
3
4
5
6
EM Revision PDT
Scott Shewbridge
RMC
Noah Vroman
MVD - Mississippi Valley Division MVK - Vicksburg
Ken Klaus - Emeritus
ERDC
Mike Navin
MVD - Mississippi Valley Division MVS - St. Louis
Neil Schwanz
MVD - Mississippi Valley Division MVP - St. Paul
Tom Brandon – Adjunct to ERDC
Virginia Tech
Regional Representatives “EM Collaborators”
Regional Levee Design PFMA Session / ATR
1
2
3
4
5
6
7
8
EM Collaborators / Regional Levee Design Contributors
Pat Conroy Geotech
MVD - Mississippi Valley Division - St. Louis
Doug Chitwood, PE GE Geotech
SPD - South Pacific Division - Los Angeles
Glen M Bellew, PE Geotech
NWD - Northwestern Division - Kansas City
Derek Morely PE, Geotech
SPD - South Pacific Division - Sacramento
Christina Neutz Geotech
LRD - Great Lakes and Ohio River Division - Louisville
Tom Mack Chief Geotech
MVD - Mississippi Valley Division - Rock Island
Mark Woodward Geotech
MVD - Mississippi Valley Division - New Orleans
James Snyder Geotech
NAD - North Atlantic Division - Baltimore
6/81
Example Case Histories
Mississippi Valley Division – New Orleans
7/81
Marchand Levee Failure 1983
8/81
Flow Slides in Sand
9/81
ACM provides the best level of protection along the rivers in the
New Orleans District’s jurisdiction due to the depth of water and
construction issues with using other materials in those depths.
10/81
Hurricane Protection – Stability
With Reinforcement Fabric
11/81
Geotextile Installation
12/81
Example Case Histories
Mississippi Valley Division – Rock Island
13/81
Design of Sand Levees
Design Philosophy
• The through seepage control must prevent the slope
failure and excessive erosion of the landside slope.
• The under seepage design criteria must control the
hydraulic gradients landward of the levee to prevent
piping and excessive uplift pressures on the landside
impervious stratum.
• Stability usually not an issue
14/81
Drury and Iowa River/Flint Creek Test
S ti
Sections
1962 and
d 1964
15/81
16
16/81
Results of Test Section:
Typical Sand Levee Cross Section
 4:1 Riverside slope
 10 foot crown
 5:1 Land side slope
► Steeper
slopes resulted in erosion due to throughseepage.
seepage
 10 h base width (The width at the base of the levee
is 10 time the height of the levee.)
► On
heights greater than 10 feet a berm is required
• 3 feet thick usually 20 feet wide.
• Design
g based on seepage
p g and stability
y analysis
y
((EM 1913)
9 3)
17/81
18/81
Example Case Histories
Northwestern Division – Kansas City
19/81
2011Missouri River Performance History
20/81
Example Case Histories
North Atlantic Division – Baltimore
21/81
Typical Levee Section
( i h MSE Wall)
(with
W ll)
NAB – Scranton
22/81
Example Case Histories
South Pacific Division – Los Angeles
23/81
Site Geology
24/81
Levee Embankment – Soil Cement
Original Levee
Typical
yp
Soil Cement
Embankment Section
Channel
Grade
Soil
Cement
Channel
Grade
Soil Cement
Soil Cement
Original Levee
Original Levee
Landside Slope
25/81
Example Case Histories
South Pacific Division – Sacramento
26/81
Design Concept: Deep Cutoff
levee
 Degrade
g
½ levee height
g
 Extend cutoff wall down
into low perm layer
 Regrade with clay core
blanket
high perm
layer
low perm
layer
27/81
Example
p Case Histories
Good Coverage for Entire Country
28/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual










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


Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
29/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
Significant Updates
30/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
31/81
Design Water Surface Elevation
 The top of barrier associated with the Design Water Surface
Elevation plus superiority plus over-wash height (or wave runup
overbuild) is termed the project (final) levee grade. Where
superiority and over-wash height are zero, the final levee grade
equals the DWSE.
 All standard geotechnical analyses (such as seepage, stability, and
erosion) shall use the DWSE with the standard design requirements
(such as effective stress/vertical gradient factor of safety, slope
stability
t bilit ffactor
t off safety,
f t etc.).
t )
32/81
Standards
 “in
in this engineering manual (EM)
(EM),
traditional design standards remain largely
unchanged from previous editions
editions, but a
risk-informed process for evaluating
required levee reliability for requesting
variances from the standards when
reliability is either too high (too expensive)
or too low (too much risk).”
33/81
Old Levee, Updated Standards?
 For existing
g levees,, all future evaluations will be based
on the same above risk-informed reliability evaluation
process regardless of the method for how it was
designed in the past
past. If the reliability of the existing levee
is too low for the current estimated consequences, then
the levee becomes a candidate for reevaluation within
the USACE
S C levee safety
f
program routine processes,
leading to further risk assessments and potential followon feasibilityy studies,, congressional
g
funding
g
authorizations, and improvement design and
construction.
34/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
35/81
ASTM Standard Tests
36/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
37/81
Geomorphology and Geophysics
38/81
TM 3-424 Mississippi River
Martis Creek Sierra Glacial
Texas Coast Littoral
39/81
Standardized
Sta
da d ed Material
ate a G
Graphics
ap cs a
and
d Co
Colors
os
40/81
Guidance On Interpretation Process
and
d Portrayal
P t
l off Supporting
S
ti Data
D t
41/81
Interpreted and Analyzed Sections
42/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
43/81
Analysis Methods
 Focus on modern FEM computer methods
while still considering “Blanket Theory”
44/81
Effective
ect e St
Stress
ess Heave/Uplift
ea e/Up t Design
es g C
Criteria
te a
45/81
Seepage Berm Design
Berm Crown
DWSE
FS = 1.6
River
Channel
FS = 1.0
Levee
Berm
Top
p Stratum
Berm Width
Pervious Substratum
Levee Toe
Berm Toe
 Use existing factor of safety criteria for critical vertical gradient /
effective stress factor of safety for uplift at end of berms.
 Iff end off berm FoS
S is less than 1.6,
1 6 then also assess likelihood off
progression of backwards erosion
46/81
Backwards Erosion / Piping Failure
C
Creep
R
Ratios
ti and/or
d/ C
Critical
iti l H
Horizontal
i
t lG
Gradients
di t
47/81
Example With Vertical and
H i
Horizontal
t lG
Gradient
di t C
Considerations
id
ti
Seepage Path Length No Berm
Creep Ratio Too Low
Seepage Path Length With Berm
Creep Ratio Sufficient (?)
Clay Blanket
Sand Aquifer
Landside Berm
Meets USACE Vertical Gradient/
Effective Stress Design Criteria
& Increases Seepage Path Length
Thin Blanket Does Not Meet
USACE Vertical Gradient/
Effective Stress Design Criteria
Vertical Boils Expected Here
48/81
Failure Modes & Event Trees
Flood Fighting Impacts
Traditional Creep Ratio or
Modern Horizontal Gradient
Computations
Traditional Vertical Gradient / Effective Stress Computations
49/81
Filtered Toe Drain (aka Trench) Design
50/81
Relief Wells
51/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
52/81
“Critical State” Soil Behavior Framework
53/81
Summary of Types of Clays, Relative Strengths, Loading
Conditions Conventional Names and Conditions Controlled
Conditions,
54/81
Selection of Strengths
Time for 99% Drainage
dense
“strength”
NC ““strength”
t
th”
Undrained Strengths
g
dense and NC “strength”
Drained Strengths
g
55/81
56/81
aka “Rapid Flood Loading” of Soft Materials
57/81
For more information see
2013 ASDSO C
Conference
f
P
Proceedings
di
58/81
Levee Seismic Risk
P tS
Post
Seismic
i i Warning
W
i / Response
R
Time
Ti
Scenarios
S
i
Earthquake
High Loss of Liffe / High Damage
Earthquake
Reduced Da
amage
Leveed Area
Elevation
No Loss of Life
WSE
Long
None
(evacuations and repairs)
Ti
Time
59/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
60/81
Analytical Framework
61/81
Typical Analysis Parameters
62/81
Design
es g o
of Overtopping
O e topp g - Resiliency
es e cy Measures
easu es
63/81
Design
es g o
of Overtopping
O e topp g - Resiliency
es e cy Measures
easu es
64/81
Transition Area Armoring
65/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Ri
Riskk
Based Decisions During Design and
Construction
Chapter 3. Field Investigations for Levees
Chapter 4
4. Laboratory Testing for Levees
Chapter 5. Borrow Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Ch t 8
Chapter
8. Sl
Slope Design
D i
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
66/81
USBR / USACE “Best
Best Practices”
Practices
67/81
Failure Modes & Event Trees
Flood Fighting Impacts
Traditional Creep Ratio or
Modern Horizontal Gradient
Computations
Traditional Vertical Gradient / Effective Stress Computations
68/81
Risk-Informed
Risk
Informed Design Progression
1
TRRL
Annu
ualized Prob
bability of F
Failure
0.1
Low Population Levee
High Population Levee
0.01
0
0
Existing Conditions
Existing Conditions
1E-3
Minimum Berm
Minimum Berm
Minimum
Mi
i
B
Berm
+ Flood Fighting
1E-4
Higher Standard Berm
Higher Standard Berm
+ Flood
Fl d Fi
Fighting
hti
1E-5
Higher Standard Berm
+ Flood Fighting
+ Improved Emergency Evacuation
1E-6
1E 7
1E-7
0.01
0.1
1
10
100
1,000
1E4
1E5
Life Loss
69/81
How “Reliable” Does the Levee Need to Be For Prior-toO t
Overtopping
i F
Failure
il
M
Modes
d When
Wh Overtopping
O t
i Controls?
C t l ?
1
TRRL
Annu
ualized Prob
bability of F
Failure
0.1
Low Population Levee
0.01
0
0
1E-3
Overtopping
1/300 years
High Population Levee
Existing Conditions
Existing Conditions
Minimum Berm
Minimum Berm
Minimum
Mi
i
B
Berm
+ Flood Fighting
1E-4
Higher Standard Berm
How
Far?
Higher Standard Berm
+ Flood
Fl d Fi
Fighting
hti
1E-5
Higher Standard Berm
+ Flood Fighting
+ Improved Emergency Evacuation
1E-6
1E 7
1E-7
0.01
0.1
1
10
100
1,000
1E4
1E5
Life Loss
70/81
Taylor Series Approximate Solution – First Order Second Moment
Can be used with virtually
y any
y limit state analysis.
y
Only Models Aleatory
•Vary each factor by +/1
sigma,
•Look
L k att variation
i ti iin response
function,
•Use that as estimate of
variance of response function
•Compare distance of “Limit State”
to “Expected” value and based on
variance estimated above,
calculate percentage of area under
lognormal curve for values greater
than the limit value.
71
Epistemic Uncertainty
“U k
“Unknown-Unknowns”
U k
”
For g
geotechnical engineering,
g
g, epistemic
p
uncertainty
y
(knowledge uncertainty) in many situations is more
important than aleatory (natural variability), because it
often cannot be estimated directly and can have
dramatic impact.
For geotechnical failure modes, both for design and
reliability assessments, the epistemic uncertainty
“unknown-unknown” challenge is common and wellknown to the profession and has been addressed
through a classic inductive-reasoning approach referred
to as the Terzaghi and Peck “Observational Method”
(P k 1969)
(Peck
1969).
Epistemic Uncertainty Risk Mitigation and
L
Levee
Safety
S f t P
Program Non-Routine
N
R ti A
Activities
ti iti
Recognizing that it is not possible to eliminate all “unknown-unknowns”
on levee systems, per current and past USACE practice,
performance monitoring and flood fighting will remain important
risk reduction measures to reduce epistemic uncertainty over time.
All ffailure
il
mode
d eventt ttree analyses
l
will
ill iinclude
l d eventt nodes
d ffor
Unsuccessful Detection and Unsuccessful Intervention.
As a part of the proposed levee safety program (Draft EC 1110-2-6072,
USACE 2014)
USACE,
2014), if performance
f
off a llevee iis d
deemed
d ttoo poor and
d
flood fighting activities too demanding and unreliable, a riskinformed process will be initiated to evaluate the needs for additional
actions If risk is high enough
actions.
enough, a variety of structural and non
nonstructural actions to increase levee reliability (i.e., change the
fragility curves) and/or decrease potential consequences will be
considered.
considered
Failure Modes & Event Trees
74/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
75/81
Explicit
p
Description
p
of Expected
p
“Flood Fighting”
g
g
76/81
Example Flood Fighting Evaluation
“More than expected
p
and, but for flood fighting,
g
g levee would have failed”
Ensley Berm, Memphis 2011
Levee did not fail, but internal erosion pipes projecting towards the river found in 2012.
77/81
Example Flood Fighting Evaluation
“Flood fighting
g
g occurred but levee failed”
L-575 Breach, NW Atchison County Levee District, Hamburg Iowa 2011
Possibly due to defects in riverside cap - fourth pipe formed and breached on June 13, 2011.
78/81
EM Chapters and Appendices














Chapter 1. Introduction
Ch t 2.
Chapter
2 Levee
L
Failure
F il
M
Modes
d and
d Risk-Based
Ri k B
d
Decisions During Design and Construction
Chapter 3. Field Investigations for Levees
Chapter 4. Laboratory Testing for Levees
Ch t 5
Chapter
5. B
Borrow A
Areas
Chapter 6. Subsurface Interpretation
Chapter 7. Seepage Evaluation and Control
Chapter 8. Slope Design
Chapter 9. Settlement
Chapter 10. Erosion Control
Chapter 11. Design and Bid Packages
Chapter 12. Levee Construction
Chapter 13. Special Features
Chapter 14. Development of Levee Operations
and Maintenance Manual














Appendix A. References
Appendix B.
B Typical Regional Designs and Typical
Design Documentation Report Contents
Appendix C. An Overview of Probabilistic Analysis
for Geotechnical Engineering Problems –
Methods to Assess of Levee Reliability
A
Appendix
di D.
D S
Subsurface
b f
I t
Interpretation
t ti Graphics
G hi
Appendix E. Levee Seepage Analysis using Blanket
Theory and Finite Element Methods
Appendix F. Analysis and Design of Seepage
Berms
Appendix G. Toe Drain Analysis and Design
Appendix H. Finite Element Method Seepage
Analysis for Relief Wells
Appendix I. Soil Behavior for Slope Stability
Appendix J. Geotextile Reinforced Embankment on
Soft Foundation
Appendix K. Use of soil cement for levee protection
Appendix L. Emergency flood protection
Appendix M. Notation
79/81
Schedule
 Independent External Peer Review (IEPR)
► Contract
in Negotiation
► Anticipated Completion December 2015
 More Review?
 Publication FY2016 Q3 or Q4
80/81
Questions / Discussion
81/81