1. Presented by Md. Imran Kabir Student No: 7664095 November 26 , 2014
Cost-Benefit Analysis on SHM Projects
Presented by
Md. Imran Kabir
Student No:
November 26 , 2014
Instructed By
Dr. Ashutosh Bagchi
Building, Civil and Environmental Engineering
Concordia University

2. Introduction (Background)
Structural Health Monitoring:
It is defined as a system that diagnose the “state” of the constituent materials of a structure at every moment during its life along with the monitoring, of the different parts and of the full assembly of these parts constituting the structure as a whole
This is partially true, but SHM is much more

3. Introduction (Background)
Structural Health Monitoring:
SHM is about
insuring safety
reducing risk
adding prestige to a structure
Reserving natural resource
Enabling remote management

4. Structural Health Monitoring
The relationship between the cost and the benefit, has become a major concept for the SHM industry

5. Defining Cost Total Cost Capital Investment SHM Design Cost
1.Integration with the structure’s design
2. Planning and project management
Hardware Costs
1. Sensors
2. Cables
3. Data acquisition and management hardware
4.Communication
Installation Costs
1.Integration with building schedule
2.Configuration
3.Commissioning
4.Reporting
Operational Cost
System Maintenance
1.Spare parts and consumables
2. Energy
3.Communication
Data Management
1. Publishing
2.Archiving
Data Analysis
1. Interpretation
2. Reporting

6. Identifying Benefits Total Benefit Hard Benefit 1.Capital Value
2. Discover Structural Reserves
3. Early Detection of Defects
4. Safe Life Time Extension etc.
Soft Benefit
1. Reduction of Risk
2. Increase Quality
3. Increase Safety
4. Image, prestige, public perception

7. Case Study Details The new St. Anthony Falls Bridge is 1,216-foot-long
10-lane concrete bridge with a 504-foot-long precast segmental main span
constructed with two parallel structures
over 500 sensors collect data regarding structural behavior and corrosion
total cost for the sensing system was about $1 million
Estimated life span 100 years

8. Overview of Sensors and Data Acquisition Systems Installed in the I-35W Bridge
Long-gauge SOFO fiber optic sensor
Vibrating Wire Strain Gauge
Concrete corrosion and Humidity sensors
Vibrating wire and temperature sensors
data logger
Accelerometer
SOFO Fiber Optic Sensor Data logger

9. Global Overview of Monitoring System of I-35 W St. Anthony Falls Bridge

10. Global Overview of Monitoring System of I-35 W St. Anthony Falls Bridge

11. Global Overview of Monitoring System of I-35 W St. Anthony Falls Bridge

12. Global Overview of Monitoring System of I-35 W St. Anthony Falls Bridge

13. Life Cycle Cost Analysis
What is Life Cycle Cost Analysis?
An economic analysis procedure that uses engineering inputs
Compares competing alternatives considering all significant costs
Expresses results in equivalent money (present value)

14. Life Cycle Cost Analysis
Cost Analysis Methods
Present Worth Method (PW)
Future Worth Method (FW)
Savings/Investment Ratio Method (SIR)

15. Life Cycle Cost Analysis
Cost Analysis Methods
Net Present Value (NPV) :
Converts all the costs to present values
Together with Internal Rate of Return (IRR)

16. Cost Considerations Life Cycle Analysis Costs Years Net Present Value
Salvage Costs
Capital Cost
Maintenance and
Inspection Cost
Rehabilitation Cost
Salvage Value

17. Life Cycle Cost Analysis for the I-35 W Bridge
Case 1 (w/o SHM)
Clifestyle = Ccapital + Coperational + CSHM
Case 2 (with SHM)

18. Life Cycle Cost Analysis for the I-35 W Bridge Case 1
Capital cost:
Ccapital = $ 234,000,000* (*Source: MnDot)
Operational Cost Calculation:
Assumption:
M & R of traffic control = $ 3,000/year
Concrete Repair = $ 5,000,000/25 year
Resurfacing= $ 150,000/25 year
Demolishing cost= $ 3,000,000
Crepair/maintenance = ($ 3,000x100+$ 5,150,000x4+$ 3,000,000)
= 23,900,000/100 = $ 239,000 / year
Reference: ISIS Educational Module 7

19. Life Cycle Cost Analysis for the I-35 W Bridge Case 1
Assumption of Manpower Cost:
No. of Inspector: 4 Engineer
Duration of Inspection: 7 days/2 months
Transportation fee: $500/engineer
Hotel fee: $100/(engineer·day)
Engineer fee: $500/(engineer·day)
Cmanpower =500x4x6+( )x4x7x6
=$ 112,800/year
Reference: MnDOT

20. Life Cycle Cost Analysis for the I-35 W Bridge
Case 1
Life Cycle Cost Analysis for the I-35 W Bridge
Additional equipment cost:
CAdE = $ 7,000/year
Total Operational Cost w/o SHM
Coperaional = Crepair/maintenance + Cmanpower + CAdE
= $ 239,000 + $ 112,800 + $ 7000
= $ 358,800/year = $ 360,000/year (say)

21. Life Cycle Cost Analysis for the I-35 W Bridge Case 1
End of Year
Capital Cost
($)
Operating Cost ($)
Increment factor (3.5%)
Total cost
Discount factor (2%)
Present Value($) 1
233000 2
360
1.04
372.60
0.980
365.29 3
1.07
385.64
0.961
370.67 4
1.11
399.14
0.942
376.12 5
1.15
413.11
0.924
381.65 … 45
4.54
0.418
684.34 46
4.70
0.410
694.40 47
4.87
0.402
704.61 48
5.04
0.394
714.98 49
5.21
0.387
725.49 50
5.40
0.379
736.16
Total Present Value without SHM ($) (in Thousand)

22. Life Cycle Cost Analysis for the I-35 W Bridge Case 2
Total Capital Cost for SHM system:
Ccapital = $1,000,000*
(*Source: MnDOT)

23. Life Cycle Cost Analysis for the I-35 W Bridge
Case 2
Operational Cost of SHM System:
Assumption of Manpower Cost:
No. of Inspector: 4 Engineer
Duration of Inspection: 7 days/4 months
Transportation fee: $500/engineer
Hotel fee: $100/(engineer·day)
Engineer fee: $500/(engineer·day)
Cmanpower = 500x4x3+( )x4x7x3
= $ 56,400/year
Sensors updating and replacing:
Csensor = $2,000/year

24. Life Cycle Cost Analysis for the I-35 W Bridge Case 2
Additional Cost in SHM System:
CAdditional = CData management + CData analysis = $ 40,000/year
Total Operational Cost in SHM System
Coperational = $ 98,400/year = $ 100,000/year (say)

25. Life Cycle Cost Analysis for the I-35 W Bridge Case 2
End of Year
Capital Cost ($)
Operating Cost ($)
Increment Factor
Total Cost ($)
Discount Factor
Present Value($) 1
234000 2
460
1.04
476.10
0.980
466.76 3
1.07
492.76
0.961
473.63 4
1.11
510.01
0.942
480.59 5
1.15
527.86
0.924
487.66 … 70
10.74
0.255 71
11.11
0.250 72
11.50
0.245 73
11.90
0.240 74
12.32
0.236 75
12.75
0.231
Total Present Value with SHM ($) (in Thousand)

26. Benefit Analysis for the New I-35 W Bridge
Impacts Bridge Failure on Economy:
Carried more than 140,000 veh/day (60,000 veh/day, 1967)
Increased commuter expenses,
Created a burden on surrounding roads creating congestion costs many switching departure times, modes, or destinations to avoid traffic
Approximately $400,000 per day in lost revenue*.
So,
Cuser = CVHT/VKT + Cadditional
= $ 400,000/day
*Source: MnDOT & FLATIRON

27. Benefit Analysis for the New I-35 W Bridge
Feng Xie et al. (2009):
Before Bridge Collapse
Time Change & Route Change
Time Fixed & Route Fixed
Time Change & Route Fixed
Time Fixed & Route Change
Daily VHT (10^6 veh. hrs)
1.427
1.432 (0.35%)
1.442 (1.09%)
1.431 (0.31%)
1.441 (1.00%)
Daily VKT (10^6 veh. kms)
86.53
86.27
(-0.31%)
86.58 (0.05%)
(-0.30%)
86.58 (0.06%)
Daily economic loss (US$) NA
71,466
220,198
62,408
203,409

28. Benefit Analysis for the New I-35 W Bridge
So,
Cuser = CVHT/VKT + Cadditional
= $ 242,210/day
= $ /year
= $ 88.5 million/year

29. Benefit Analysis for the New I-35 W Bridge Case 1
End of Year
User Benefit ($)
Increment factor (1.5%)
Total Benefit ($)
Discount Factor (3.5%)
Present Value ($) 1
88500
1.02
1.000 2
1.03
0.980 3
1.05
0.961 4
1.06
0.942 5
1.08
0.924 … 45
1.95
0.418 46
1.98
0.410 47
2.01
0.402 48
2.04
0.394 49
2.07
0.387 50
0.379
Total Benefit w/o SHM ($) (in Thousand) 3,

30. Benefit Analysis for the New I-35 W Bridge Case 2
End of Year
Operating Benefit($)
Increment Factor (1.5%)
Total Cost($)
Discount Factor (3.5%)
Present Value($) 1
88500
1.00
1.000 2
1.02
0.980 3
1.03
0.961 4
1.05
0.942 5
1.06
0.924 … 70
2.79
0.255 71
2.84
0.250 72
2.88
0.245 73
2.92
0.240 74
2.96
0.236 75
3.01
0.231
Total Benefit with SHM ($) (in Thousand)
5,565,

31. Benefit-Cost Analysis for the New I-35 W Bridge
CASE CASE2
NO SHM SHM
BCR <
Difference of BCR = 4
CASE 2 (WITH SHM) IS ACCEPTABLE!

32. Data Analysis and Results....
Personal Details of Motorcycle Rider
66% at
Range of
25-40 yrs.
2% age
Below 20 yrs.
*Source: FHWA

33. Saving from SHM 31% savings Bridge Candidate for Replacement:
Is possible
From SHM
Bridge Candidate for Replacement:
Cost of Replacement, no SHM: 100%
Cost of SHM: 3%
Bridges found to be OK: 20%
Bridges needing rehabilitation: 20%
Cost of rehabilitation: 30%
Bridges needing replacement: 60%
Cost with SHM: 3%+20%x30%+60%=69%
Saving from SHM: 31%!!!

34. Recommendations
Compared to the conventional methods, Wireless Sensor Networks (WSN) provide comparable functionality at a much lower price (Sukun Kim et al. 2007)
Benefit-Cost analysis of new I-35 W bridge using WSN should be evaluated in future studies.

35. Thank You