Using Structural Health Monitoring to Reduce Risks for Historical Buildings

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3 Using Structural Health Monitoring to Reduce Risks for Historical Buildings Gianluca Bacchiega - IRS srl R&D bacchiega@irsweb.it

4 an Engineering Company 4

5 Qtub Minar New Delhi (India) San Marco Church L Aquila (Italy) 5 Ponte del mare Pescara (Italy)

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7 PROBLEM STATEMENT Damage detection and assessment, Structural design or assessment, Maintenance and retrofitting of existing structures Structural behavior and control during earthquakes STRUCTURAL HEALTH MONITORING (SHM) Continuous or short term monitoring of structural behavior connected to the evaluation of structural evolution with the passing of time 7

8 APPLICATION TO HISTORICAL BUILDINGS On-site testing and monitoring can be considered key activities for a conscious knowledgebased approach in the conservation of the architectural heritage. INVESTIGATIONS Structural behaviour definition (ex: validation of behavioural models) MONITORING Permanent structural controls (continuous on site inspections) MONITORING TECHNIQUES STATIC MONITORING DYNAMIC MONITORING 8

9 IRS Platform for SHM Automated system for structural and environmental parameters monitoring and analysis 1. Wired and wireless National Instruments based measurement Hardware 9

10 IRS Platform for SHM Automated system for structural and environmental parameters monitoring and analysis 1. Wired and wireless National Instruments based measurement Hardware 2. Custom or Third party components integration (routers, enclosures, industrial PC, sensors) 10

11 IRS Platform for SHM Automated system for structural and environmental parameters monitoring and analysis 1. Wired and wireless National Instruments based measurement Hardware 2. Third party component integration (routers, enclosures, industrial PC, sensors) 3. LabVIEW software application developed by IRS for channels configuration, data acquisition and visualization, calculations, log and UMTS/3G data transfer 11

12 Structural monitoring solutions for ancient and new structures. 12

13 Roman amphitheater: Arena di Verona SHM IS AN ALTERNATIVE TO STRENGTHENING GEOMETRIC AND STRUCTURAL FEATURES Ellipse (152.43m x m) Two annular galleries and 73 radial masonry walls Inner masonry: multi-leaf with inner core Wing - Ala : freestanding structure remaining four arches of the outer ring, h=30.75 m 13 HISTORICAL NOTES - PAST INTERVENTIONS I century: construction of the amphitheater XII century: collapse of the outer ring 1939: First intervention on the Wing : buttresses construction before WWII

14 Architecture of an Integrated Measurement System NI CompactDAQ hardware combines a 1-, 4-, or 8-slot chassis with over 50 measurement-specific NI C Series I/O modules and can operate stand-alone with a built-in controller or connect to a host computer over USB, Ethernet, or Wi-Fi. Sensor Measurement Device Software 14

15 Where and what to measure? DYNAMIC MONITORING 16 SINGLE-AXIS ACCELEROMETERS SENSITIVITY: MV/(M/S²) FREQUENCY RANGE (± 10 %): HZ RESOLUTION(DA 10,000 HZ): M/S² OPERATING TEMPERATURE : C STATIC MONITORING 20 DISPLACEMENT TRANSDUCERS VOLTAGE: 0 10 V MEASUREMENT RANGE: 10 CM HYSTERESIS: < 0.01 MM OPERATING TEMPERATURE: C 8 PZ inner gallery 12 PZ «Arcovoli» of the first level ENVIRONMENTAL MONITORING 4 TEMPERATURE/RH VOLTAGE: 0 10 V PRECISION: +/- 2 % RH +/- 0.2 C MEASUREMENT RANGE: 0 100% RH - 20/0 50 C 15

16 CRACK OPENING VS. TEMERATURE CRACK OPENING VS. TIME SHM UNDER OPERATIONAL CONDITIONS: STATIC MONITORING RESULTS 18

17 SEISMIC MONITORING : EARTHQUAKE EVENTS MAIN SHOCK: 25 JANUARY 2012 Prealpi Venete (VR) :54:46 Magnitude: 4.2 Depth 10.3 Km Distance: 11,5 Km MAIN SHOCK: 29 MAY 2012 Pianura Padana-Emiliana (MO) :00:03 Magnitude: 5.8 Depth 10.2 Km Distance: 75 Km [m/s^2] Max. Acc. Base = 0,62 m/s 2 Max Acc. Wing = 1,93 m/s acc7 0.5 acc8 Max. Acc. Base = 0,08 m/s 2 Max Acc. Wing = 0,98 m/s acc Amplif. factor = 3, tempo [s] Amplif. factor = 12,56 COMPARISON: MAX. ACCELERATIONS, AMPLIFICATION FACTORS AND ELASTIC RESPONSE SPECTRA Seismic event BASE TOP WING TOP AMPHITHEATER PGA [m/s 2 ] Max. Acc. [m/s 2 ] Amplif. factor Max Acc. [m/s 2 ] Amplif. factor 25/01/2012 0,619 1,93 3,11 1,251 2,02 29/05/2012 0,078 0,98 12,56 0,40 5,13 19

18 A TOOL TO HELP CONSERVATION : MODELING AND NUMERICAL SIMULATION. MODE n EXP FREQ [Hz] FEM FREQ [Hz] 1 1,92 1,68 2 2,61 2,42 3 4,83 4,91 4 5,87 5,89 5 6,10 6,20 6 7,10 7,18 20

19 A network of ancient monuments and civil structure in Verona (Italy) 21

20 Do not understimate hardware configuration and sensor placement 22

21 Do take advantage of platform flexibility Customer asked for non intrusive fissuration monitoring: We developed a brand new image acquisition application to monitor ancient frescos in Conegliano 23

22 Do work with partners Civil structure department Padua University 24

23 Do not forget Human Machine Interface 25

24 4. Development Conclusion and perspective: SHM, smart city and IoT CLOUD COMPUTING INVESTIGATION PHASE INTERVENTION PHASE EVALUATION PHASE MAINTENANCE PHASE 26

25 Thank you 27

26 Before you go, take the survey. 28

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