This document discusses the implementation of a structural health monitoring system for a cable-stayed bridge in Barddhaman, India. The monitoring system measures forces on six critical bridge cables using electromagnetic sensors. It provides real-time data on cable forces and temperatures. The system was load tested and found to accurately monitor cable forces. It will allow engineers to safely monitor the bridge's structural integrity over its lifespan.

1. By
Rajesh Prasad
Executive Director (Metro)
Rail Vikas Nigam Limited
Implementation of Structural Health Monitoring
System for live Monitoring of the Cable Forces
at Barddhaman ROB

2. Good Physique
Regular Check ups
Preventive Measures &
Medicines
Proper & Timely Cure &
Restoration
A KEY TO LONG HEALTH LIFE OF MAN/STRUCTURE
Good Construction
Regular Inspections
Preventive Measures &
Materials
Proper & Timely Repairs
& Restoration

3. SCOPE
• Why Structural Health Monitoring (SHM)
required?
• How Structural Health Monitoring (SHM)
function in this case?
• Methodology and Monitoring
• Output and Report generation

4. SHM Consists of :-
• Design, Installation, Commissioning of SHMS
• Operation, Maintenance, Data Recording,
Analysing and Reporting
• Sensors to measure environmental and
structural response factors (F&T).
• Signal acquisition solution, signal verification
and temperature adjustment, conversion of
signal to digital format etc.

5. • LARSA 4D model for design
• Wind tunnel test
• Use of precast RCC slabs to avoid scaffolding on deck
• Composite structures for easier construction
• Monolithic Back Span
• Durable painting by epoxy based paint of Akzonobel
• Erection scheme
• LUSAS model for Construction Stage Analysis
• Geometry Control during execution.
• ROBO Control (Monitoring System) by M/s Mageba
FEATURES

6. • For monitoring of the structural health of the bridge during its service
life, 6 nos. of sensors have been installed on the stay cables
subjected to maximum loads.
• The structural monitoring system issues alarm notification based on
measurements by the on-structure instrumentation when pre-
defined threshold values of structural loads are passed. Alarm criteria
can be configured based on the structural design of the bridge
MONITORING SYSTEM (ROBO-CONTROL)

7. • Long term monitoring system.
• Measurement of forces on stay cables.
• Compact Monitoring System.
• System sustenance to extreme conditions.
• Graphical data output in web interface
with redundant data storage.
MAJOR COMPONENTS OF THE MONITORING SYSTEM

8. SENSOR SCHEME
6(six) Nos. of sensors have been provided on the central pylon and
extreme cables to monitor the forces on these critical cables which are
subjected to maximum load. (10% of the total Cables need to be
instrumented)

9. Sensors Used
SENSOR SCHEME
Electromagnetic Sensors

10. Login Window

11. First screen after login

12. Cockpit display

13. Cable Force and Temperature variation

14. Live Force on Cable 7001

15. Month wise variation

16. • Placed inside
protected box
• Round the clock
running
• Data redundancy
• Internet connection
required
• Uninterrupted power
supply required
SYSTEM INSIDE THE PYLON

17. Sensor tied up on the required strand Sensor on strand inside the AV tube
INSTALLATION
Onsite calibration Cabling left inside for future connections

18. LOAD TEST
Cable
No.
Observed Value Reference range
Reading during
load test on
30.08.2016 (KN)
Lower limit
(KN)
Upper limit
(KN)
7001 55.7 33.39 77.28
7002 89.4 72.22 112.95
7003 75.4 69.71 109.44
7016 99.8 84.97 117.01
7017 78.1 50.99 91.21
7018 75.8 41.70 82.26

19. LIVE MONITORING
Cable
No.
Observed Value Reference range
Reading on
04.01.2017 (KN)
Lower limit
(KN)
Upper limit
(KN)
7001 55.6 33.39 77.28
7002 84.8 72.22 112.95
7003 83.4 69.71 109.44
7016 96.8 84.97 117.01
7017 73.5 50.99 91.21
7018 67.8 41.70 82.26

20. LOAD TEST AND LIVE MONITORING SAMPLE
Cable
No.
Observed Value Reference range
Reading during
load test on
30.08.2016 (KN)
Reading on
07.01.2017
(KN)
Lower
limit
(KN)
Upper
limit (KN)
7001 55.7 55.4 33.39 77.28
7002 89.4 84.6 72.22 112.95
7003 75.4 83.1 69.71 109.44
7016 99.8 96.8 84.97 117.01
7017 78.1 73.3 50.99 91.21
7018 75.8 67.3 41.70 82.26

21. Main benefits of Structural
Health Monitoring:
• Design Confirmation.
• Safety of the structure.
• Understanding behaviour
of structures at certain
environmental
conditions.
• Load Validation
• Generation of time
dependent record of
structure’s behaviour for
further studies/decision.
CONCLUSION