Effects of consecutive earthquakes on increased damage and response of reinforced concrete structures

다국어 초록 (Multilingual Abstract)

A large main shock may consist of numerous aftershocks with a short period. The aftershocks induced by a large main shock can cause the collapse of a structure that has been already damaged by the preceding main shock. These aftershocks are important factors in structural damages. Furthermore, despite what is often assumed in seismic design codes, earthquakes do not usually occur as a single event, but as a series of strong aftershocks and even fore shocks. For this reason, this study investigates the effect and potential of consecutive earthquakes on the response and behavior of concrete structures. At first, six moment resisting concrete frames with 3, 5, 7, 10, 12 and 15 stories are designed and analyzed under two different records with seismic sequences from real and artificial cases. The damage states of the model frames were then measured by the Park and Ang\'s damage index. From the results of this investigation, it is observed that the sequences of ground motions can almost double the accumulated damage and increased response of structures. Therefore, it is certainly insufficient to ignore this effect in the design procedure of structures. Also, the use of artificial seismic sequences as design earthquake can lead to non-conservative prediction of behavior and damage of structures under real seismic sequences.

참고문헌 (Reference)

1 Matrix laboratory (MATLAB),

2 Charney, F.A., "Unintended consequence of modeling damping in structures: Rayleigh damping, PEER/ATC-72-1" American Society of Civil Engineers 2006

3 Dreger, D., "The large aftershocks of the Northridge earthquake and their relationship to mainshock slip and faultzone complexity" 87 (87): 1259-1266, 1997

4 Amadio, C., "The effects of repeated earthquake ground motions on the non-linear response of SDOF systems" 32 (32): 291-308, 2003

5 Computers., "Structural and Earthquake Engineering Software" 2016

6 Fragiacomo, M., "Seismic response of steel frames under repeated earthquake ground motions" 26 : 2021-2035, 2004

7 Moustafa, A., "Response of nonlinear single-degree-of freedom structures to random acceleration sequences" 33 : 1251-1258, 2011

8 Erochko, J., "Residual drift response of SMRFs and BRB frames in steel buildings designed according to ASCE 7-05" 137 : 589-599, 2011

9 Scott, M.H., "Plastic hinge integration methods for force- based beam- column elements" 132 (132): 244-252, 2006

10 Li, Q., "Performance evaluation and damage assessment of steel frame buildings under main shockaftershock sequences" 36 : 405-427, 2007

11 PEER, "PEER NGA Database" Pacific Earthquake Engineering Research Center, University of California

12 Opensees, "Open System for Earthquake Engineering Simulation (OpenSees)" Pacific Earthquake Engineering Research Center, University of California

13 Hancock, J., "Numbers of scaled and matched accelerograms required for inelastic dynamic analyses" 37 (37): 1585-1607, 2008

14 Hatzigeorgiou, G.D., "Nonlinear behaviour of RC frames under repeated strong ground motions" 30 : 1010-1025, 2010

15 Moustafa, A., "Modeling critical groundmotion sequences for inelastic structures" 13 (13): 665-679, 2010

16 "Minimum Design Loads for Buildings and Other Structures, ASCE/SEI 7-05"

17 Park, Y.J., "Mechanistic seismic damage model for reinforced concrete" ASCE 111 (111): 722-739, 1985

18 Permanent Committee for Revising the Iranian Code of Practice for Seismic Resistant Design of Buildings, "Iranian Code of Practice for Seismic Resistant Design of Buildings, Standard No. 2800, 3rd Edition"

19 Faisal, A., "Investigation of story ductility demands of inelastic concrete frames subjected to repeated earthquakes" 44 : 42-53, 2013

20 Hatzigeorgiou, G.D., "Inelastic displacement ratios for SDOF structures subjected to repeated earthquakes" 31 : 2744-2755, 2009

21 Park, Y.J., "IDARC: Inelastic damage analysis of frame shear-wall structures, Technical Report NCEER-87-0008" National Center for Earthquake Engineering Research, State University of NewYork at Buffalo 1987

22 Petrini, L., "Experimental verification of viscous damping modeling for inelastic time history analyses" 12 (12): 125-145, 2008

23 Garcia, J.R., "Effect of seismic sequences in reinforced concrete frame buildings located in soft-soil sites" 63 : 56-68, 2014

24 Atkinson, G.M., "Earthquake time histories compatible with the 2005 NBCC uniform hazard spectrum" 2009

25 Luco, N., "Dynamic versus static computation of the residual capacity of a mainshockdamaged building to withstand an aftershock" 2004

26 Nagae, T., "Design implications of large-scale shake-table test on four-story reinforced concrete building" 112 (112): 135-146, 2015

27 Park, Y.J., "Damage-limiting aseismic design of buildings" 3 (3): 1-26, 1987

28 Huang, W., "Damage assessment of RC frame structures under Mainshock-Aftershock seismic sequences" 2012

29 Kunnath, S.K., "Cumulative seismic damage of reinforced concrete bridge piers, Technical Report, NCEER 97-0006" State Univ. of New York 1997-, 1997

30 Moustafa, A., "Characterization of earthquake ground motion of multiple sequences" 3 (3): 629-647, 2012

31 Hatzigeorgiou, G.D., "Behavior factors for nonlinear structures subjected to multiple near-fault earthquakes" 88 : 309-321, 2010

32 Haselton, C.B.S., "Beam-column element model calibrated for predicting flexural response leading to global collapse of RC frame buildings" Berkeley Pacific Earthquake Engineering Research Center College of Engineering University of California 2007