Design of a Bridge Inspection System
(BIS) To Reduce Time & Cost
Ahsan Zulfiqar
Miryam Cabieses
Andrew Mikael
Namra Khan
Faculty Advisor:
Dr. Lance Sherry
Sponsor:
Dr. Lattanzi (GMU CEIE)
Department of Systems Engineering and Operations Research - 2014
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Context
❖ The FHWA administers 607,380 bridges
➢ Average age is 42 years.
❖ Manual inspection process
➢ Every two years
■ 1-3 days to inspect one bridge
■ $4,500 per inspection
➢ Bi-Annual inspection cost is $2.7
billion for the U.S.
❖ Bridges infrastructure is deteriorating
➢ Increasing maintenance cost
➢ Increasing inspection process cycle
T. J. Ryan, J. E. Mann, Z. Chill, and B. Ott, “Bridge Inspector’s Reference Manual.” Federal Highway Administration, Dec-2012.
http://www.infrastructurereportcard.org/a/#p/bridges/conditions-and-capacity
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Structurally Deficient Bridges
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Bridge Types & Components
Arch:
Beam Bridge
Beam:
Cantilever:
Beam bridge inspection process
Suspension:
T. J. Ryan, J. E. Mann, Z. Chill, and B. Ott, “Bridge Inspector’s
http://www.ikonet.com/en/visualdictionary/transport-and-machinery/road-transport/
Reference Manual.” Federal Highway Administration, Dec-2012.
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Main Components & Failure Types
Component
Deck
Material
Failure Types
Concrete Section loss
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Roadway
Primary member damage (ex: collision…)
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Side walk
Columns with spalling and rebar section loss
Substructure
Concrete Structure critical point (ex: Fracture
critical…)
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Abutments
Severe deterioration
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Piers
High stress area
Super-Structure
Metal
Cracking
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Floor beams
Fatigue (less stiff)
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Girders
Corrosion (Loss of mass)
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Stringers
Missing connection
Truss
Metal
Bending (due to high stress)
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Percentage to Failure Type
Material
Metal
Concrete
Failure Types
Inspection Method Percentage to cause
failure
Cracking
Visual/Physical
Fatigue (less stiff)
Physical
Corrosion (Loss of mass)
Visual/Physical 3.26%
Bending (over load)
Visual
Missing connection
Visual/Physical
Section loss
Visual/Physical 20.65%
High stress area
Visual/Physical
13.05%
2.17%
Structure crack at critical point (ex: Visual/Physical 16.3%
Fracture critical…)
Severe deterioration
Visual
Bridge Failure Rates, Consequences, and Predictive Trends by Wesley Cook
Utah State University
2.17%
Note: This is a Partial List of failure
percentages
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General Inspection Procedures
http://www.fhwa.dot.gov/bridge/nbis/pubs/nhi12049.pdf
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Beam Bridge Inspection Sequence
http://www.fhwa.dot.gov/bridge/nbis/pubs/nhi12049.pdf
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Human Inspector Rating Criteria
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Problem Statement
❖ The FHWA requires evaluation of all bridges
➢ Time consuming: 1-3 days for on-site inspection
➢ Requires closing lanes for the span of the inspection
■ Causing traffic congestion
➢ Bi-Annual inspection cost is $2.7 billion in the U.S.
➢ Hazardous for personnel
➢ Rating of inspection is subjective
❖ Increasing demand to inspect bridges
➢ Increase inspection cycle to 6 months - 1 year
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Stakeholder Analysis
Lane Shutdown Time and Cost
Hires a consulting engineering company to design a bridge
+
+
Bid
s
Pro the p
vide roje
s th ct to
eb
ridg contra
ed
esig ctors
n
ay
ble er p
w
/Lo
Lia
bs
Jo
Hires them for safety inspection
Designs the Bridge
se
Funds the bridge
DOT
Inspection
Team
-
/
In
e
sp
cts
dg
bri
ts
s
Win
-/
Construction
Team
and
c
stru
n
o
c
b
the
ridg
/
e
Bridge Users
Bridge
+
th
id
eb
le
b
Lia
Liable
e
Interactions
Primary
Secondary
Tensions
Design
Engineer
Lo
Funds part of the bridge and take partial ownership
FHWA
Support
Oppose
Neutral
+
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Need Statement
1. Reduce cost
a. Labor Cost
b. Traffic Control Cost
c. Equipment Cost
2. Increase the rate of inspection/detection/prevention of bridge
failures
3.
Remove safety risk for inspection personnel
4. Maintain/Increase Quality
a. Make inspection process objective
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Scope
● District Department of
Transportation (DDOT)
Total Bridges: 199
Structurally Deficient Bridges: 121
● Theodore Roosevelt Bridge Beam
Bridge
•3,143 ft
•5 spans
•6 supports
•concrete & metal
•6 Lanes
•50 years
Above Water Inspection
http://www.fhwa.dot.gov/bridge/deficient.cfm
Theodore Roosevelt Bridge
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Requirements
Mission Requirements
Design Goal
1.
BIS shall reduce cost
< $4,500
2.
BIS shall reduce time of inspection
4 hours
3.
BIS shall be safe for users
<16 failures (Range of 14 years)
4.
BIS shall be objective
Quantitative results
Functional Requirements
BIS shall Inspect all bridge components
BIS shall categorize the components according to the pass/fail criterion
The pass/fail criterion shall allow the components to be classified into a repaired, and/or
replaced category
BIS shall store the data acquired onto the ground base
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Operational Concept of the proposed
system
Material
Type of failure
Inspection
Method
Metal
Cracking
Visual/Physical
Fatigue (less stiff)
Physical
Percentage
to cause
failure
Proposed Detection
Method
13.05%
Vibration Analysis
Concrete
Corrosion (Loss of mass)
Visual/Physical
Bending
Visual
Missing connection
Visual/Physical
Section loss
Visual/Physical
3.26%
Image Capturing device
20.65%
Structure crack at critical
point (ex: Fracture
critical…)
Visual/Physical
16.3%
Severe deterioration
Visual
2.17%
Bridge Failure Rates, Consequences, and Predictive Trends by Wesley Cook
Utah State University
Vibration Analysis
Image Capturing device
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General Structure of Proposed
System
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Structural Vibration
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Vibration is repetitive motion that can be
measured and observed in a structure.
➢ Unavoidable but deciphers what changes in
vibration mean.
Vibration analysis:
➢ Free vibration
➢ Forced vibration
➢ Sinusoidal vibration
➢ random vibration
Helps characterize the behavior of the structure
Factors that affect vibration are characterized by
the following parameters:
➢ mass
➢ stiffness
➢ damping
knowing these values can predict how structure
will respond to vibration
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Functional Design for Structural
Vibration Analysis
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How Accelerometers
Work
❖ Structural vibrations can be measured by electronic sensors
that convert vibration motion into electrical signals.
❖ Motion Sensors/Accelerometers
❖ Based on Piezoelectric Effect
pcb.com
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BIS Design Alternatives
Time
Manual
Inspection
Cost
Safety
Reliability
Actual inspection (1-3 days)
$4500/inspection
Traffic,
Animals,
Poison Ivy,
Drowning
Mounted
Sensors with
cables
Total time to perform
Inspection (simulation)
Acquisition Cost: $51,000
Concurrent Cost: $450
Not
Hazards for
inspectors
≥ 95%
UAV + Mounted
Sensors with
low-power
communication
systems
Total time to perform
Inspection (simulation)
Acquisition Cost: $75,000
Not
Hazards for
inspectors
≥ 95%
Concurrent Cost: $1000/year
95%
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Design Alternatives
Design Alternatives
Manual
Pros
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Cons
Current
95% reliable
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Sensor + Cables
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UAV + Communication system + Sensors
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Easy
installation
Fast power
supply
Fast data
transmission
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Convenient
Safe
Quick-real
time data
Within Range
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Labor cost
Time
consuming
Not efficient
Subjective
Hazardous
Requires many
accessories
Acquiring new
skills
Complex
Security and
integrity of data
Acquiring new
skills
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Design Alternative 2: Sensor +
Cables
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Design Alternative 3: Sensors +
UAV + Communication System
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Antennas
Batteries
Memory
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Design Alternative 3: Sensors +
UAV + Communication System
•
•
•
Wireless Sensor Network
Monitor physical or environmental conditions
Pass their data to a main location.
•Built of nodes
–point to point network
–advanced multi hop wireless mesh network
•Components
–Radio transceiver with antenna
–Microcontroller
–Energy source
searchdatacenter.techtarget.com
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Method of Analysis
Forces
Vibration Analysis
Model
Number of
Accelerometers
Life -Cycle
Cost Model
Load Capacity
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Bridge Parameters
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Manual
Sensors +
Cables
Sensors +
UAV + Comm
Quality /
Performance
Utility
Utility
(weights)
Cost
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Vibration Analysis Model
Output
Input
●
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Number of Lanes
Mass/Velocity of Cars
Fluctuation in
Acceleration
External Vibration
Forces of Structure
Min/Max Load Capacity
Length
Time Span
Vibration
Analysis
Model
Characterize the
behavior and
performance of
structure
Natural frequency
Less stiffness
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Vibration Analysis Model (Cont.)
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DOE for Vibration Analysis
Input
Length
# of Lanes
4
3,200 ft
6
8
L : Length (3,200 ft)
l : # of lanes (4,6,8)
m : mass of car
Output
Value of
(m)
Value (v)
S
L, M, H
f(L,l,m,k,c)
M
L, M, H
f(L,l,m,k,c)
L
L, M, H
f(L,l,m,k,c)
S
L, M, H
f(L,l,m,k,c)
M
L, M, H
f(L,l,m,k,c)
L
L, M, H
f(L,l,m,k,c)
S
L, M, H
f(L,l,m,k,c)
M
L, M, H
f(L,l,m,k,c)
L
L, M, H
f(L,l,m,k,c)
Value of (k)
k : Stiffness
c : Damping effect
v : velocity
Value of (c)
Freq. Response
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Life-Cycle Cost Model
Manual
Mounted
Sensors with
cables
UAV + Mounted
Sensors with low
power com.
system
-
$51,000
$75,000
Concurrent Cost
$4,500/inspection
$450/year
$1000/year
Indirect Cost
-
$400/person
$800/person
Total Cost
(50 years)
$24.8 Million
$2.5 Million
$5.6 Million
Acquisition Cost
Assumptions:
Accelerometers use are specific for bridge vibrations (longer life span)
Maintenance (testing the equipment: giving known input are receiving predicted output)
Calculations were made having 6 lanes each direction
Total Cost of BI for DDOT [199 Bridges (SD -> inspected annually)]
Bridge Diagnostics, Inc.
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Multi-Attribute Utility Theory (MAUT)
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Agenda
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Context
Problem Statement
Stakeholder Analysis
Need Statement
Scope
CONOPS
Proposed Solution
Simulation
Project Plan/Budget
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Work Breakdown Structure
(WBS)
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Project Plan/Critical Path
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Project Budget
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Risk Assessment
Risk Description
Mitigation Strategy
Data collection:
● If we lack quantitative data, then we have to
make assumptions.
●
Supplement similar data from similar
studies.
Reliability:
● Not meeting the current reliability of bridge
inspection with the proposed solutions.
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Use the criteria currently used to be able to
meet the current reliability of the inspection
process.
Simulation:
● Critical task to measure if our alternative
designs are accurate.
● Failure to complete on time could delay the
whole project.
●
Start early and try to supplement more time
as necessary.
Work through winter break
Stakeholders:
● Unable to fully understand the objectives of
the stakeholders, and unable to arrange
further contact to obtain data.
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Initiate contact with our sponsor and
VDOT/FHWA until we obtain a response
with the requested information.
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Questions
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