1. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Monitoring of the dynamic behaviour of a building at Parque das Nações Lisboa Instituto Superior de Engenharia de Lisboa Maria Ana Baptista

2. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Project funded by the Portuguese Science Foundation (FCT) DYNASEIS - DYNAMIC BEHAVIOUR OF A RE–INFORCED CONCRETE STRUCTURE UNDER SEIMIC LOAD MAIN OBJECTIVES Study of dynamic response of a re-inforced concrete structure using ambient vibrations (output only) Experimental study of natural frequencies Implementation of numerical modelling of the structure

3. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 The Building of Portugal Telecom Offices Located at the newly residential and office area of Lisboa, called Parque das Nações (Expo98) Built in 1998 Area 11 000 m2 TARGET

4. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 The Tower has 12 floors above ground and four basement levels, and is responsible for the entire telecommunications network in the Parque das Nações complex (Expo 98). Two floors are entirely occupied by the telecom central, being the remaining floors used by Marconi (PT subsidiary) as their head-office. TARGET

5. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 TARGET

6. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 1.Forced-vibration tests are more difficult to perform and require heavy equipment and logistics; 2.State-of-the-art vibration generators do not have the capability to excite to resonance all significant modes of all structures (Çelebi,2000); 3.Different vibrational modes can be detected from a single measurement; 4.Forced vibrations can damage the structure. However, 1. Modal characteristics corresponding to low amplitude vibrations may be different from large higher levels of shaking (Ventura & Schuster, 1996). WHY AMBIENT VIBRATION TEST ?

7. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 The Telecom Tower is located close to the Gare do Oriente railway station (designed by Santiago Calatrava) and is one source of ambient noise). AMBIENT VIBRATION TEST Others are urban traffic, wind, etc...

8. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 DYNAMIC MODELLING Dynamic analysis was performed by the designers of the structure but the information available is scarce. The building is a reinforced concrete structure consisting of boat shape flat plate slabs. floor slabs are 0.25 m thick (floors 5 to 11), 0.30 m (floors 1 to 4) and 0.40 m (ground floor); floor slabs are directly support by columns; analysis were conducted up to 8 modes but only the first 6 were considered relevant; fundamental frequency: 0.55 Hz; Exterior Support beam For lifts and windows

9. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 INSTRUMENTS - SENSORS Dynamic Range155 dB Frequency BandDC to 200 Hz Scale Amplitude0,25g a 4,00g Dynamic Range140 dB Frequency BandDC to 200 Hz Scale Amplitude0,25g a 4,00g Uniaxial Acelerometer Episensor FBA ES-U: Triaxial Acelerometer Episensor FBA ES-T: 1 6

10. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 INSTRUMENTS - ACQUISITION Dynamic Range> 114 dB Sampling Rate20 a 200 Hz Output24 bit Acquisition ModeContínuous/Trigger ClockGPS (accuracy 0,5 ms) Acquisition System: Kinemetrics Altus K2 Digital Recorder:

11. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 FIRST TEST Field Operations: 30 December 2002 Triaxial: Top Floor (fixed) Continuous 10 min observations in all even floors with the following geometry: Reference Sensors Roving Sensors

12. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Sampling Rate – 250 Hz Channels 1,2,3 – (x,y,z) triaxial reference acelerometer 4 – y direction south tower 5 – x direction south tower 7 – x direction north tower Time base – TU (sinal GPS) Scale 2,5 V/1g FIRST TEST

13. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 FIRST TEST Cables were deployed along the floors...

14. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Successive setups (30.12.2002): Floor_10 Floor_08 Floor_06 Floor_04 Floor_02 FIRST TEST To maintain a good quality control the sensor layout was kept the same when moving from setup to setup.

15. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 FIRST TEST Example of event record from setup 6.

16. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 ESD obtained by FFT Triaxial record on the top floor y direction x direction z direction (vertical)

17. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Event recorded at the 6th floor: A – transversal B – longitudinal C – longitudinal ESD obtained by FFT A B C

18. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Successive setups 24.012003: Floor_11 Floor_07 Floor_05 Floor_03 Floor_01 - closed FIRST TEST Field Operations: 24 January 2003 Triaxial: Top Floor (fixed) Continuous 10 min observations in all uneven floors with the following geometry:

19. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 free-field station: it is impossible to locate a free-field station at a distance greater than 1.5 - 2 times the height of the nearest/tallest building (Çelebi, 2000); 6 HOUR CONTINUOUS ACQUISITION 10 February 2003 and 11 February 2003

20. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 continuous observation can be achieved only in the following places: 11 th, 6 th, 0 th floors triaxial accelerometer at floor – 4 (foundation level) 6 HOUR CONTINUOUS ACQUISITION 10 February 2003 and 11 February 2003 Data Acquisition – 6 hours Sampling rate 100Hz Data is stored in a PCMCIA 64 MB

21. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Data acquisition system K2 was installed at 6th floor Connection of the transverse and logintudinal sensors to the junction box that is connected to k2 and after that The sensors were oriented parallel to the tranverse (x) and longitudinal (y) axes of the building 6 HOUR CONTINUOUS ACQUISITION 10 February 2003 and 11 February 2003

22. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 Conclusion of the Finite Element Modeling (FEM) of the building – SAP2000 in order to avoid definitive installation at nodal points of the structure; Experimental data analysis: Modal analysis – ArteMis; Validation of dynamical analysis Improvement of the methodology: - in earthquake prone areas - different building typology NEXT ACTIVITIES

23. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 ACKNOWLEDGMENTS The author wish to thank the Portuguese Telecom Board of Administration and LNEC (Laboratório Nacional de Engenharia Civil) for all support. DYNASEIS TEAM: M. A. Baptista, A. Campos Costa, A. Afilhado, C. S. Oliveira, P. Mendes, M. Vasques This project was funded by Portuguese Science Foundation (FCT) project POCTI-36071-ECM

24. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 REFERENCES Çelebi M., 2000 Seismic Instrumentation of bulidings, USGS OF report 00157 Ventura & Schuster, 1996 d Structural dynamic properties of a re inforced high rise building during construction. Can. J. Civil Eng 23,950-970.

25. The Dynaseis experiment ELSA, JRC Ispra Italy 2003 STRUCTURAL RESPONSE Vibration Excitation Frequency range Hz Displ. range µm Velocity Range mm/s Accel. Range µg Traffic: road, rail1 - 801 - 2000.2 - 502 - 100 Wind0.1 - 1010 - 10 5 Earthquakes0.1 - 3010 -10 5 0.2 - 4002 - 200 Acoustic: traffic and machinery outside 10 - 2501 - 1000.2 - 302 - 100 Machinery inside1 - 10001 - 1000.2 - 302 - 100 Adapted from ANSI: S247 - 1990