An Investigation into Effect of Soil-Structure Interaction on Seismic Behavior of Strong Back Bracing System under Near and Far-Field Earthquakes

Document Type : Original Research

Authors
M. taghizadeh 1
M. Gholhaki 2
O. Rezaifar 2
1 MSc, civil faculty, Semnan university, Semnan, iran
2 Associate professor, civil faculty, Semnan university, Semnan, iran.
DOI: 10.22034/22.3.177
Abstract
During the past years, researchers have developed ideas to thoroughly investigated into the behavior of structural bracing systems. Accordingly, one of these emerging systems is the Strong Back Bracing System (SBBS) by which the inter-storey drifts are maintained constant to prevent occurrence of failure. This system is comprised of the components of conventional concentrically braced frames together with a strong truss whose presence is aimed at uniform distribution of drifts along height of the building. This truss precludes concentration of damages in one or several stories in the concentrically braced frames. On the other hand, the near-filed earthquakes differ from the far-field ones in terms of both amplitude and frequency content. Thus, it is required to study the effects of such earthquakes on behavior of the SBBS. In addition to earthquake, the soil underlying the structure can affect the structural responses especially in cases when structure rests on soft soils. This system is comprised of the components of conventional concentrically braced frames together with a strong truss whose presence is aimed at uniform distribution of drifts along height of the building. This truss precludes concentration of damages in one or several stories in the concentrically braced frames. On the other hand, the near-filed earthquakes differ from the far-field ones in terms of both amplitude and frequency content. Thus, it is required to study the effects of such earthquakes on behavior of the SBBS. In addition to earthquake, the soil underlying the structure can affect the structural responses especially in cases when structure rests on soft soils. Typically, the codes provide methods for structural analysis assuming that the structure is located on a rigid base whereas in reality, this assumption does not always hold true highlighting the need for inclusion of soil-structure interaction into the analyses. Accordingly, this paper deals with seismic behavior of the structures equipped with the SBBS considering the soil-structure interaction under near and far-field earthquakes. In this respect, 3, 6 and 12-storey structures resting on stiff and loose soil (soil type II and IV according to classification of Standard 2800) have been analyzed. To this end, nonlinear time-history analyses using seven far and near-field earthquakes for both cases of rigid and flexible base, have been carried out. The results indicate that maximum roof displacement of 3, 6 and 12-storey structures founded on stiff soils (soil type II) vary insignificantly under the far and near-field earthquakes. Conversely, in the case of soft soils (soil type IV), displacements have increased by 2.93 to 18.22%. Moreover, it was found that drift ratios for the structures on stiff soil, in the case of 3 and 6-storey structures, increases slightly and reduced by 6.75% for the 12-storey structure. In the case of soft soil, all structures under the near-field motion, incurred increase in drift ratios by 11.67% and in the case of far-field, 3 and 6-storey structures experienced 4.86% decrease and conversely, the 12-storey structure encountered 7.7% increase. In addition, ratio of residual drift of the 3, 6 and 12-storey structures under average of near-field earthquakes, has decreased and increased by 8.52 and 36.02 in the case of stiff and soft soils, respectively.

Keywords

Subjects

[1] Khatib I.F., Mahin S.A., Pister K.S. 1988 Seismic behavior of concentrically braced frames, Earthquake Engineering Research Center, University of California, Berkeley, CA, Rept. No. UCB/EERC-88/01.
[2] Chen C.C., Chen S.Y., Liaw J.J. 2001 Application of low yield strength steel on controlled plasticfication ductile concentrically braced frames, Canadian J. Civil Eng., 28(5): 823-836.
[3] Mahin S.A., Uriz P., Aiken I.D., Field C., Ko E. 2004 Seismic performance of buckling restrained braced frame systems, Proceedings, 13th World Conference on Earthquake Engineering, Paper No. 1681, Vancouver, B.C., Canada.
[4] Lai J.W., Tsai K.C., Lin S.L., Hsiao P.C. 2004 Large scale buckling restrained brace research in Taiwan, Proceedings,1st Asia Conference on Earthquake Engineering, Manila, Philippines.
[5] Aiken I.D, Nims D.K., Kelly J.M. 1992 Comparative study of four passive energy dissipation systems, Bull. NewZealand Nat. Soc. Earthq. Eng., 25 (3): 175-192.
[6] McCormick J., DesRoches R., Fugazza D., Auricchio F. 2007 Seismic assessment of concentrically braced steel frames with shape memory alloy braces, ASCE J. Struct. Eng., 133(6): 862-870.
[7] Christopoulos C., Tremblay R., Kim H.J., Lacerte M. 2008 Self-centering energy dissipative bracing system for the seismic resistance of structures: development and validation, J. Struct. Eng., 134(1): 96-107.
[8] Tremblay R., Haddad M., Martinez G., Richard J., Moffatt K. 2008 Inelastic cyclic testing of large size steel bracing members. Proceedings, 14th World Conference on Earthquake Engineering, Beijing, China.
[9] Yang C.S., DesRoches R., Leon R.T. 2010 Design and analysis of braced frames with shape memory alloy and energy-absorbing hybrid devices. Eng. Struct., 32: 498-507.
[10] Kiggins S., Uang C.M. 2006 Reducing residual drift of buckling-restrained braced frames as a dual system. Eng. Struct., 28: 1525-1532.
[11] Sabelli R. 2001 Research on Improving the Design and Analysis of Earthquake-Resistant Steel-Braced Frames. Earthquake Engineering Research Institute, the 2000 NEHRP Professional Fellowship Report, PF2000-9, Oakland, CA.
[12] Tremblay, R. and Tirca, L. 2003 Behavior and Design of multi-story zipper concentrically braced steel frames for the mitigation of soft-story response. Proceedings of the conference on behavior of steel structures in seismic areas, P.471-477.
[13] Yang C.S., DesRoches R., Leon R.T. 2010 Design and analysis of braced frames with shape memory alloy and energy-absorbing hybrid devices. Eng. Struct., 32: 498-507.
[14] Lai, J. and Mahin, S. 2014 Strongback System: A Way to Reduce Damage Concentration in Steel-Braced Frames. J. Struct. Eng., 10.1061/ (ASCE) ST.1943-541X.0001198, 04014223.
[15] Barbara G. Simpson and Stephen A. Mahin, M. 2018 Experimental and Numerical Investigation of Strongback Braced Frame System to Mitigate Weak Story Behavior. J. Struct. Eng., 2018, 144(2): 04017211.
[16] Toorani A., Gholhaki M., & Vahdani R. 2020 The investigation into the effect of consecutive earthquakes on the strongback bracing system. In Structures (Vol. 24, pp. 477-488)
[17] Trifunac M. D., Stewart J. P., Fenves G. L., & Seed R. B. 2000 Seismic Soil-Structure Interaction in Buildings. I: Analytical Methods; Seismic Soil-Structure Interaction in Buildings. II: Empirical Findings. Journal of Geotechnical and Geoenvironmental Engineering, 126(7), 668-672.
[18] El Ganainy H., & El Naggar M. H. 2009 Seismic performance of three-dimensional frame structures with underground stories. Soil Dynamics and Earthquake Engineering, 29(9), 1249-1261.
[19] Kim Y. S., & Roesset J. M. 2004 Effect of nonlinear soil behavior on inelastic seismic response of a structure. International Journal of Geomechanics, 4(2), 104-114.
[20] Forooghi H., Behnamfar F., and Madani B. 2016 Case Study for Evaluation of Dynamic Characteristics of Adjacent Buildings. Journal AJSR Civil and Enviromental Engineering, 48 (3), pp.111-115.
[21] Mirzaie F., Mahsuli M., & Ghannad M. A. 2017 Probabilistic analysis of soil‐structure interaction effects on the seismic performance of structures. Earthquake Engineering & Structural Dynamics, 46(4), 641-660.
[22] Balool S., Gholhaki M., & Rezayfar O. 2018 Study Behavior of Thin Steel Plate Shear Wall System by Effect of the Soil - Structure Interaction under Away from the Fault and Near the Fault Earthquakes. Civil Engineering, 35.2 (2.2), 81-95. (In Persian)
[23] Gerami M., & Abdollahzadeh D. 2012 Estimation of forward directivity effect on design spectra in near field of fault. Journal of Basic and Applied Scientific Research, 2(9), 8670-8686.
[24] Hassani N., Bararnia M., & Amiri G. G. 2018 Effect of soil-structure interaction on inelastic displacement ratios of degrading structures. Soil Dynamics and Earthquake Engineering, 104, 75-87.
[25] Earthquake Resistant Design of building Regulations, 2800, 4th edition. Building and housing Reseach Center (2015).
[26] AISC (American Institute of Steel Construction). (2005). Seismic Provisions for Structural Steel Buildings, Chicago.
[27] Iranian National Building Code. (2013). Part 10, Design of Steel Building.
[28] Peer berkeley center. Peer ground motion database. https://ngawest2.berkeley.edu/users/sign_in?unauthenticated=true.
Modares Civil Engineering journal
Volume 22, Issue 3
May and June 2022
Pages 177-192