Torsion Effect on the RC Structures using Fragility Curves Considering with Soil-Structure Interaction

Document Type : Regular Paper


1 Department of civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Civil Engineering Department, Sharif University of Technology, Tehran, Iran

3 Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran


The existence of torsion, as well as consideration of the Soil-Structure Interaction (SSI), increase the natural periods of the structure resulting from a subsequent decrease in the seismic demand of the system. This paper summarizes the probabilistic assessment in order to evaluate the collapse fragility curves in concrete moment resisting structure with different mass center eccentricities. A 12-story, 3-D, moment resisting concrete structure with fixed-base and deliberating SSI, both types of one- and two-way eccentricities is employed to estimate the collapse fragility curve by the IM-based approach. In consonance with the obtained results, increasing the torsion as a result of shifting the mass centers decreases the median of the collapse fragility curve. In addition, it was observed that the SSI consideration for soil type D with shear wave velocity of 180m/s to 360m/s leads to reduction of the median of collapse capacity by  in the presence of torsion effect due to one- and two-way mass center eccentricities in range of 0-20% of the building's plan dimensions respectively. Put it differently, the fixed-base assumption overestimates the median of collapse capacity and leads to unsafe design. Moreover, shifting the mass centers of all the stories up to 20% of the building's plan dimensions, with or without the consideration of the SSI, decreases the median of collapse capacities and increases the seismic vulnerability of the building. Accordingly, the fixed-base assumption can be underestimated the dispersion range of the collapse fragility curve. The result reveals that the mentioned differences cannot be neglected.


Main Subjects

[1] Jalayer, F., & Cornell, C. A. (2003). “A technical framework for probability-based demand and capacity factor (DCFD) seismic formats.” RMS.
[2] Cornell, C. A., Jalayer, F., Hamburger, R. O., Foutch, D. A. (2002). “Probabilistic basis for 2000 SAC federal emergency management agency steel moment frame guidelines.” Journal of structural engineering, Vol. 128 no.4, pp. 526-533.
[3] Ibarra, L. F., Krawinkler, H. (2005). “Global collapse of frame structures under seismic excitations.” Berkeley, CA: Pacific Earthquake Engineering Research Center, pp. 29-51.
[4] Haselton, C. B., Liel, A. B., Dean, B. S., Chou, J. H., Deierlein, G. G. (2007). “Seismic collapse safety and behavior of modern reinforced concrete moment frame buildings.” In Structural engineering research frontiers, pp. 1-14.
[5] Zareian, F., Krawinkler, H. (2007). “Assessment of probability of collapse and design for collapse safety.” Earthquake Engineering & Structural Dynamics, Vol. 36(13), pp. 1901-1914.
[6] Vamvatsikos, D., Cornell, C. A. (2002). “Incremental dynamic analysis.” Earthquake Engineering & Structural Dynamics, Vol. 31(3), pp. 491-514.
[7] Stoica, M., Medina, R. A., McCuen, R. H. (2007). “Improved probabilistic quantification of drift demands for seismic evaluation.” Structural Safety, Vol. 29(2), pp. 132-145.
[8] Kappos, A. J., Panagopoulos, G. (2010). “Fragility curves for reinforced concrete buildings in Greece.” Structure and Infrastructure Engineering, Vol. 6(1-2), pp. 39-53.
[9] Haselton, C. B., Liel, A. B., Deierlein, G. G., Dean, B. S., Chou, J. H. (2010). “Seismic collapse safety of reinforced concrete buildings. I: Assessment of ductile moment frames.” Journal of Structural Engineering, Vol. 137(4), pp. 481-491.
[10] Lignos, D. G., Hikino, T., Matsuoka, Y., Nakashima, M. (2012). “Collapse assessment of steel moment frames based on E-Defense full-scale shake table collapse tests.” Journal of Structural Engineering, Vol. 139(1), pp. 120-132.
[11] Palermo, M., Hernandez, R. R., Mazzoni, S., Trombetti, T. (2014). “On the seismic behavior of a reinforced concrete building with masonry infills collapsed during the 2009 L'Aquila earthquake.” Earthquake and Structures, Vol. 6(1), pp. 45-69.
[12] Bolisetti, C. (2014). “Site response, soil-structure interaction and structure-soil-structure interaction for performance assessment of buildings and nuclear structures.” (Doctoral dissertation, State University of New York at Buffalo).
[13] ATC-3-06 (1978). “Amended tentative provisions for the development of seismic regulations for buildings.” ATC publications ATC 3-06, NBS Special Publication 510, NSF Publication 78-8, Applied Technology Council. US Government Printing Office: Washington DC.
[14] NEHRP Consultants Joint Venture. (2012). Soil-Structure Interaction for Building Structures. NIST GCR.
[15] NIST GCR 12-917-21 (2012). “Soil-Structure Interaction for Building Structures”. U.S. Department of Commerce National Institute of Standards and Technology Engineering Laboratory Gaithersburg, MD 20899, September 2012.
[16] Renzi, S., Madiai, C., Vannucchi, G. (2013). “A simplified empirical method for assessing seismic soil-structure interaction effects on ordinary shear-type buildings.” Soil Dynamics and Earthquake Engineering, Vol. 55, pp. 100-107.
[17] Saouma, V., Miura, F., Lebon, G., Yagome, Y. (2011). “A simplified 3D model for soil-structure interaction with radiation damping and free field input.” Bulletin of Earthquake Engineering, Vol. 9(5), pp. 1387.
[18] Rayhani, M. T., El Naggar, M. H. (2012). “Physical and numerical modeling of seismic soil-structure interaction in layered soils.” Geotechnical and Geological Engineering, Vol. 30(2), pp. 331-342.
[19] Pecker, A., Paolucci, R., Chatzigogos, C., Correia, A. A., & Figini, R. (2014). “The role of non-linear dynamic soil-foundation interaction on the seismic response of structures.” Bulletin of Earthquake Engineering, Vol. 12(3), pp. 1157-1176.
[20] Sáez, E., Lopez-Caballero, F., Modaressi-Farahmand-Razavi, A. (2013). “Inelastic dynamic soil–structure interaction effects on moment-resisting frame buildings.” Engineering structures, Vol. 51, pp. 166-177.
[21] Figini, R., Paolucci, R. (2017). “Integrated foundation–structure seismic assessment through non‐linear dynamic analyses.” Earthquake Engineering & Structural Dynamics, Vol. 46(3), pp. 349-367.
[22] Raychowdhury, P. (2011). “Seismic response of low-rise steel moment-resisting frame (SMRF) buildings incorporating nonlinear soil–structure interaction (SSI).” Engineering Structures, 33(3), 958-967.
[23] Khoshnoudian, F., Ahmadi, E., Kiani, M., Tehrani, M. H. (2015). “Dynamic instability of Soil-SDOF structure systems under far-fault earthquakes.” Earthquake Spectra, Vol. 31(4), pp. 2419-2441.
[24] Ghandil, M., & Behnamfar, F. (2015). “The near-field method for dynamic analysis of structures on soft soils including inelastic soil–structure interaction.” Soil Dynamics and Earthquake Engineering, Vol. 75, pp. 1-17.
[25] Ghandil, M., Behnamfar, F., Vafaeian, M. (2016). “Dynamic responses of structure–soil–structure systems with an extension of the equivalent linear soil modeling.” Soil Dynamics and Earthquake Engineering, Vol. 80, pp. 149-162.
[26] Anvarsamarin, A., Rofooei, F. R., Nekooei, M. (2018). “Soil-Structure Interaction Effect on Fragility Curve of 3D Models of Concrete Moment-Resisting Buildings.” Shock and Vibration, Vol. 2018.
[27] Shakib, H., Homaei, F. (2017). “Probabilistic seismic performance assessment of the soil-structure interaction effect on seismic response of mid-rise setback steel buildings.” Bulletin of Earthquake Engineering, Vol. 15(7), pp. 2827-2851.
[28] Behnamfar, F., Banizadeh, M. (2016). “Effects of soil–structure interaction on distribution of seismic vulnerability in RC structures.” Soil Dynamics and Earthquake Engineering, Vol. 80, pp. 73-86.
[29] Ghandil M., Behnamfar F. (2017). “Ductility demands of MRF structures on soft soils considering soil-structure interaction”, Soil Dynamics and Earthquake Engineering Vol. 92, pp. 203–214.
[30] Karapetrou, S. T., Fotopoulou, S. D., Pitilakis, K. D. (2015). “Seismic vulnerability assessment of high-rise non-ductile RC buildings considering soil–structure interaction effects.” Soil Dynamics and Earthquake Engineering, Vol. 73, pp. 42-57.
[31] Pitilakis, K., Crowley, H., Kaynia, A. M. (2014). “SYNER-G: typology definition and fragility functions for physical elements at seismic risk.” Geotechnical, Geological and Earthquake Engineering, Vol, 27.
[32] ACI Committee, American Concrete Institute, International Organization for Standardization. (2008). “Building code requirements for structural concrete (ACI 318-08) and commentary”. American Concrete Institute.
[33] ASCE 7-10. (2010). “Minimum Design Loads for Buildings and Other Structures.” American Society of Civil Engineers, Reston, VA, USA.
[34] ETABS, Structural Analysis Program, Computers and Structures Inc. (2013). Berkeley, CA, USA.
[35] OpenSees (2011). “Open System for Earthquake Engineering Simulation.” University of Berkeley, Berkeley, CA, USA.
[36] Terzic, V. (2011). “Force-based element vs. Displacement-based element.” University of Berkeley, OpenSees, NEES, & NEEScomm.
[37] Spacone, E., Filippou, F. C., Taucer, F. F. (1996). “Fibre beam–column model for non‐linear analysis of R/C frames: Part I. Formulation.” Earthquake Engineering & Structural Dynamics, Vol. 25, no. 7, pp. 711-725.
[38] Spacone, E., Filippou, F. C., Taucer, F. F. (1996). “Fibre beam–column model for non‐linear analysis of R/C frames: part II. Applications.” Earthquake engineering and structural dynamics, Vol. 25, no. 7, pp. 727-742.
[39] Mander J B., Priestley M J N., Park R. (1988). “Observed stressstrain behavior of confined concrete.” Journal of Structural Engineering, Vol. 114, no. 8, pp. 1827–1849.
[40] KSU-RC. (2007). “KSU-RC: Moment-Curvature, Force and Interaction Analysis of Reinforced Concrete Member, V 1.0.11, Inc.” Kansas State University, Kansas, USA.
[41] Wolf, J. P. (1995). “Cone models as a strength-of-materials approach to foundation vibration.” In Proceedings 10th European Conference on Earthquake Engineering (No. LCH-CONF-1995-004, pp. 583-592).
[42] Schnabel, P.B., Lysmer, J., Seed, H.B. (1972). “SHAKE: A Computer Program for Earthquake Response Analysis of Horizontally Layered Sites,” Report, UCB/EERC-72/12, Univ. of California at Berkeley.
[43] EduPro Civil System, Inc. (1998). ProShake Users Manual – Ground Response Analysis Program, EduPro Civil System, Inc., Redmond, Washington.
[44] ASCE/SEI Seismic Rehabilitation Standards Committee. (2007). “Seismic rehabilitation of existing buildings (ASCE/SEI 41-06).” American Society of Civil Engineers, Reston, VA.
[45] Pacific Earthquake Engineering Research Center (PEER), PEER Next Generation Attenuation (NGA) Database. (2013). https://
[46] Federal Emergency Management Agency. (2005). “Improvement of nonlinear static seismic analysis procedures.” FEMA 440, prepared by Applied Technology Council (ATC-55 Project).
[47] Shome, N. (1999). “Probabilistic seismic demand analysis of nonlinear structures.” Stanford University.
[48] Ibarra, L. F., Krawinkler, H. (2005). “Global collapse of frame structures under seismic excitations.” Berkeley, CA: Pacific Earthquake Engineering Research Center, pp. 29-51.
[49] Zareian, F., Krawinkler, H., Ibarra, L., Lignos, D. (2010). “Basic concepts and performance measures in prediction of collapse of buildings under earthquake ground motions.” The Structural Design of Tall and Special Buildings, Vol. 19(1‐2), pp. 167-181.