Structural health monitoring and concept of sustainability in engineering

1. Structural health monitoring and concept of sustainability in engineering Princeton University, Supélec, Ecole Centrale Paris and Alcatel-Lucent Bell Labs Workshop on Information, Energy and Environment, June 23-24, 2008 Presented by Branko GlišićSMARTEC SA, Switzerland

2. Outline • Challenges of modern world • Concept of sustainability in civil engineering • Structural health monitoring as a support to concept of sustainability • Examples from practice • Closing remarks

3. Challenges of modern world • Protection of natural environment • Maintenance of built environment • Approaching the lifetime limits of civil infrastructure • Mitigation risks from natural or human-made disasters • Shortage of fresh water • Shortage of energy • …

4. Concept of sustainability • New construction materials and new structural systems to be developed and applied • New structures to be performance oriented and old structures rehabilitated or recycled • Long-term maintenance programs are to be implemented • Implementation of structural health monitoring as a tool providing objective and reliable real-time information on structural performance and condition

5. Monitoring and monitored parameters Periodical or continuous record of parameters over a certain periods (long-term, short-term or comb.) MONITORING = Mechanical (strain, curvature,…) Physical (temperature, humidity,…) Chemical (PH, CL-, SO3-, …) Other PARAMETERS = Material Local structural Global structural LEVEL =

6. Monitoring Inspection Repair Diagnosis SHM – nervous system of structure Pain Exams Diagnosis Cure

7. Why monitoring? • Increase safety  preserve human lives, environment and goods • Management based on objective and reliable data  decrease of economic losses due to repair, maintenance, reconstruction and for users • Better exploitation of traditional materials, better exploitation of existing structures  reducing of construction and exploitation costs

8. Why monitoring (continued)? • New materials, new construction technologies, new structural systems are used  increase of knowledge, control of design, verification of performance, creation and calibration of models • Plan and reduce life-cycle operation costs • Limit social, economical, environmental and aesthetical impact in case of deficiency • Supports concept of sustainable engineering

9. SHM Methods - Challenge / Motivation Best monitored structure Concept of nervous system directly applicable to the structures? Sensors everywhere Complex, complicated and expensive!  Fiber Optic methods for SHM, FESHM and Integrity Monitoring

10. “Parallel” and “triangular” topologies “Parallel” and “crossed” topologies “Parallel” topology “Simple” topology Finite Element SHM concept Tilt meter • Structure is divided into parts called cells • Each cell is equipped with long-gagefiber optic sensor combination, called a topology, which in the best manner corresponds to the expected strain field in the cell • Results obtained from each cell are linked, using appropriate algorithms, in order to retrieve the global structural behavior

11. FESHM, different types of structures

12. Distributed deformation sensors for integrity monitoring Event detection and localization Expected average strain without damage Integrity monitoring • Distributed fiber optic sensing provides for integrity monitoring – event (e.g. damage) detection and localization Event that generate local strain change Average strain [me]

13. Overflow Seepage Slow local movement in slope Integrity monitoring applications Distributed deformation sensor for integrity monitoring Distributed deformation and temperature sensor Distributed sensors in sections, along vaults, in boreholes

14. SHM example – I10 bridge (US) High performance pre-stressed concrete (new material) Model? Performance? Performance from monitoring Different models vs. monitoring

15. C.M.P. SHM example – Swiss Expo ‘02 Recycled pipes as piles Performance? Safety?

16. SHM example – Gota bridge (SE) Old structure (1939) – fatigue cracks in steel Maintenance, in-time repair – lifetime extension until 2020 Integrity monitoring over 5 main girders

17. SHM example – Pļaviņu hes (LV) The largest hydropower plant in Latvia Risk of shortage of energy in case of structural failure Disastrous impact to environment Early warning, in-time maintenance

18. SHM example – Prezzo (IT) Village built on landslide – risk for population and goods Land sliding accelerated with rain and snow melting Monitoring for mitigation risk

19. SHM example – ZEM (EU) Composite onboard storage tank for gas powered vehicles Low weight/consumption/emissions Safety/periodic controls/maintenance

20. SHM example – Vienna water supply City’s 2nd water supply line, aged (built in 1900) Cracks present in tunnel, important losses of water Monitoring to improve water management

21. SHM example – Brine pipeline (DE) Gas tank construction in a salt mine near Berlin Cleaning of salt mine with hot water, evacuation of the brine using 55 km pipeline Risk of structural failure / 3rd party interference / leakage Safety, ecological consequences, interruption of construction process, delay and economical losses Source: GESO, Jena, Germany

22. Acknowledgements • New Mexico State University (US) • Swiss Expo ’02 (CH) • Norwegian Geotechnical Institute (NO) • Trafikkontoret (SE) • Latvenergo, VND2 and Aigers (LV) • EU Commission and ZEM partners (EU) • Vienna Water Supply and RISS (AT) • GESO (DE)

23. Instead of conclusions • Butterflies and dinosaurs date from the same epoch… • Recent research leads scientists to the conclusion that butterflies have survived because they have been equipped with better sensors than dinosaurs, and thus are able to adapt to environmental changes. • Should we build structures with a butterfly or dinosaur destiny?