Advertisement

Structural Assessment of a School Building in Sankhu, Nepal Damaged Due to Torsional Response During the 2015 Gorkha Earthquake

  • Supratik Bose
  • Amin Nozari
  • Mohammad Ebrahim Mohammadi
  • Andreas Stavridis
  • Moaveni Babak
  • Richard Wood
  • Dan Gillins
  • Andre Barbosa
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

This paper discusses the structural assessment of a red-tagged four-story school building in Sankhu, Nepal. The building had a masonry-infilled reinforced concrete frame which was severely damaged during the 2015 Gorkha Earthquake. The concentration of damage in the west end of the first story indicates that the frame exhibited torsional response to the ground excitation. The authors visited the structure 2 months after the earthquake, collected LiDAR scans, and recorded the ambient vibrations of the damaged structure. The LiDAR data has been used to create a three-dimensional point cloud of the building which has allowed the identification of the locations and geometry of the major cracks but also the measurement of the permanent deformations of the building. The structure was also instrumented with four unidirectional accelerometers on every floor; two at opposite corners, to capture the translational and torsional motion. The translational and torsional modes have been identified with an operational modal analysis method and have been used to validate a finite element model of the structure. The comparison indicates that the model can capture the modal properties of the structure utilizing the strut modeling approach for the infill panels.

Keywords

Infilled RC frame 2015 Nepal Earthquake LiDAR scan Stochastic subspace identification method Finite element model 

Notes

Acknowledgements

The researchers from the University at Buffalo and Oregon State University were supported by NSF Awards #1545595 and #1545632, respectively. The authors would also like to acknowledge the support of National Society of Earthquake Technology (NSET) in Nepal, through the support of Ramesh Guragain and Dev Kumar Maharjan. The collaboration of other researchers including Patrick Burns, Matt Gillins, Michael Olsen, Giuseppe Brando, Davide Rapone, Enrico Spacone, Rajendra Soti, Humberto Varum, António Arêde, Nelson Vila-Pouca, André Furtado, João Oliveira, Hugo Rodrigues, Marco Faggella and Rosario Gigliotti during the reconnaissance trip and in the collection of data is greatly appreciated as well. However, the opinions expressed in this paper are those of the authors and do not necessarily represent those of the sponsor or the collaborators.

References

  1. 1.
    Rai, D.C., Singhal, V., Raj, B.S., Sagar, L.: Reconnaissance of the effects of the M7.8 Gorkha (Nepal) earthquake of April 25, 2015. J. Geomatics Nat. Hazards Risk 7(1), 1–17 (2015). Taylor and FrancisCrossRefGoogle Scholar
  2. 2.
  3. 3.
    United State Geological Survey (USGS). http://earthquake.usgs.gov/hazard/apps/vs30 (2015)
  4. 4.
    Brando, G., Rapone, D., Spacone, E., Barbosa, A., Olsen, M., Gillins, D., Soti, R., Varum, H., Arede, A., Vila-Pouca, N., Furtado, A., Oliveira, J., Rodriges, H., Stavridis, A., Bose, S., Faggella, M., Gigliotti, R., Wood, R.L.: Reconnaissance report on the 2015 Gorkha earthquake effects in Nepal. XVI Congegno ANIDIS, L’AQUILA (2015)Google Scholar
  5. 5.
    Chaulagain, H., Rodrigues, H., Spacone, E., Varum, H.: Seismic assessment of RC structures with infill masonry panels in Nepal—Sensitivity analysis. In: Second European Conference on Earthquake Engineering and Seismology, Istanbul, Aug 2014Google Scholar
  6. 6.
    Pradhan, P.L.: Composite actions of brick infill wall in RC frame under in-plane lateral load. Ph.D. Dissertation, Tribhuvan University, Pulchowk Campus (2009)Google Scholar
  7. 7.
    Guldur, B., Hajjar, J.F.: Laser-based structural sensing and surface damage detection, Report No. NEU-CEE-2014-03, Department of Civil and Environmental Engineering, Northeastern University, Boston (2014)Google Scholar
  8. 8.
    Wood, R.L.: Methods of structural damage characterization for infrastructure. 34th Annual Structural Congress, Structural Engineer (2014)Google Scholar
  9. 9.
    Olsen, M.J., Kuester, F., Chang, B., Hutchinson, T.: Terrestrial laser scanning based structural damage assessment. J. Comput. Civ. Eng. 24(3), 264–272 (2010)CrossRefGoogle Scholar
  10. 10.
    Olsen, M.J., Cheung, K.F., Yamazaki, Y., Butcher, S., Garlock, M., Yim, S., Piaskowy, S., Robertson, I., Burgos, L., Young, Y.L.: Damage assessment of the 2010 Chile earthquake and tsunami using terrestrial laser scanning. Earthq. Spectra 28(S1), S179–S197 (2012)CrossRefGoogle Scholar
  11. 11.
    Riegl, Riegl VZ-400 Datasheet, Riegl Laser Measuring Systems GmbH, Austria (2014)Google Scholar
  12. 12.
    Trimble, Faro Focus3D × 130 high-speed 3d laser scanner datasheet. Trimble Navigation Limited, Westminster (2015)Google Scholar
  13. 13.
    Leica, Leica Cyclone SURVEY 9.1, Processing laser scans into civil/survey deliverables. Leica Geosystems AG, Heerbrugg (2014)Google Scholar
  14. 14.
    Junag, J.N., Pappa, R.S.: An eigensystem realization algorithm for modal parameter identification and model reduction. J. Guid. Control. Dyn. 8(5), 620–627 (1985)CrossRefzbMATHGoogle Scholar
  15. 15.
    Farrar, C., James III, G.: System identification from ambient vibration measurements on a bridge. J. Sound Vib. 205(1), 1–18 (1997)CrossRefGoogle Scholar
  16. 16.
    Moaveni, B., He, X., Conte, J.P., Restrepo, J.I., Panagiotou, M.: System identification study of a 7-story full-scale building slice tested on the UCSD-NEES shake table. J. Struct. Eng. 137(6), 705–717 (2010)CrossRefGoogle Scholar
  17. 17.
    Welch, P.D.: The use of fast Fourier transform for the estimation of power spectra: a method based on time averaging over short, modified period programs. IEEE Trans. Audio Electroacoust. 15(2), 70–73 (1967)MathSciNetCrossRefGoogle Scholar
  18. 18.
    Verboven, P., Parloo, E., Guillaume, P., Van Overmeire, M.: Autonomous structural health monitoring—part I: modal parameter estimation and tracking. J. Mech. Syst. Signal Process. 16(4), 637–657 (2002)CrossRefGoogle Scholar
  19. 19.
    McKenna, F., Fenves, G.L., Scott, M.H., Jeremic, B.: Open system for earthquake engineering simulation (opensees). Pacific Earthquake Engineering Research Center, University of California, Berkeley (2000)Google Scholar
  20. 20.
    Stavridis, A.: Analytical and experimental study of seismic performance of reinforced concrete frames infilled with masonry walls. Ph.D. Dissertation, University of California, San Diego (2009)Google Scholar
  21. 21.
    Stavridis, A., Shing, P.B.: Finite element modeling of nonlinear behavior of masonry-infilled RC frames. J. Struct. Eng. 136(3), 285–296 (2010)CrossRefGoogle Scholar

Copyright information

© The Society for Experimental Mechanics, Inc. 2016

Authors and Affiliations

  • Supratik Bose
    • 1
  • Amin Nozari
    • 2
  • Mohammad Ebrahim Mohammadi
    • 3
  • Andreas Stavridis
    • 1
  • Moaveni Babak
    • 2
  • Richard Wood
    • 3
  • Dan Gillins
    • 4
  • Andre Barbosa
    • 4
  1. 1.Department of Civil, Structural and Environmental EngineeringUniversity at BuffaloBuffaloUSA
  2. 2.Department of Civil and Environmental EngineeringTufts UniversityMedfordUSA
  3. 3.Department of Civil EngineeringUniversity of Nebraska LincolnLincolnUSA
  4. 4.Department of Civil and Construction EngineeringOregon State UniversityCorvallisUSA

Personalised recommendations