Advance Researches in Civil Engineering

Advance Researches in Civil Engineering

Strength Reduction Factor of Soil-Structure Systems in Comparison to Fixed-Base Structures

Document Type : Original Article

Authors
Morvarid Hajian 1
Reza Attarnejad 2
1 PhD. candidate, School of civil Engineering, University of Tehran
2 Professor, School of civil Engineering, University of Tehran
10.30469/arce.2024.224606
Abstract
In this research, a proposed correlation was suggested to predict the strength reduction factor of soil-structure systems when compared to structures with rigid bases. In recent years, several studies have focused on how structural dynamic parameters evolve, taking into account the flexibility of the substrate. The strength reduction factor is a crucial parameter in seismic design, and it is calculated as the ratio of elastic strength demand to inelastic strength demand to ensure that the displacement ductility demand does not exceed a specific target ductility ratio. This study utilized various non-linear and two-dimensional time-history analyses on shear building models with 3, 5, 10, and 15 stories, fixed-base periods ranging from 0.1 to 3 seconds, and target ductility ratios of 2, 4, and 6, placed on the soil. 22 far-field seismic accelerometers were utilized to expose the structures. To account for soil-structure interaction, class D and E soils were utilized. Observing the results showed that the strength reduction factor of structures was decreased by soil-structure interaction. The softer the soil, the greater the soil-structure interaction effects, thus the smaller the strength reduction factor. In the three-story building, the change from type D soil to type E soil resulted in a 7% decrease in the strength reduction factor. However, this difference was not significant in the ten-story building when comparing the two types of soil. Using the results obtained, a correlation was established to determine the structural strength reduction factor based on the strength reduction factor of the rigid base case.
Keywords
Soil-structure interaction
Strength reduction factor
Ductility ratio
Modeling soil
Inelastic strength demand
1-Ali, T., Eldin, M.N. and Haider, W., 2023. The effect of soil-structure interaction on the seismic response of structures using machine learning, finite element modeling and ASCE 7-16 methods. Sensors, 23(4), p.2047.
2-Shi, Y., Wang, D., Qin, H., Chen, X., Han, J. and Zhang, Z., 2023. Strength reduction factor spectra for SDOF systems with structural fuses. Soil Dynamics and Earthquake Engineering, 169, p.107895.
3-Requena-Garcia-Cruz, M.V., Bento, R., Durand-Neyra, P. and Morales-Esteban, A., 2022, April. Analysis of the soil structure-interaction effects on the seismic vulnerability of mid-rise RC buildings in Lisbon. In Structures (Vol. 38, pp. 599-617). Elsevier.
4-Maharjan, S. and Bahadur, K., 2021, March. Study of Soil-Structure Interaction Effects on Seismic Analysis. In Proceedings of 9th IOE Graduate Conference (Vol. 12).
5-Waqas, M., (2018). “Identification of an Efficient Method for Practicing Designers to Incorporate Soil-Structure Interaction Effects”, Doctoral dissertation, CAPITAL UNIVERSITY.
6-Tahghighi, H. and Rabiee, M., (2015). “Nonlinear Soil-Structure Interaction Effects on Building Frames: A Discussion on the Seismic Codes”. Journal of Seismology and Earthquake Engineering, 17(2), pp.141-151.
7-Kanwal, F., (2017). “Evaluation of Response Modification Factor in Consideration of Soil-Structure Interaction”, Master Thesis.  
8-Tabatabaiefar, S.H.R., 2012. “Determining seismic response of mid-rise building frames considering dynamic soil-structure interaction”, Doctoral dissertation.
9-Karimzada, N.A., (2015). “Performance-Based Seismic Design of reinforced concrete frame buildings: A direct displacement-based approach”, Master's thesis, İzmir Institute of Technology.
10-Folic, R. (2015). “Performance Based Seismic Design of Concrete Buildings Structures - Bases”, International conference, Contemporary achievements in civil engineering 24. April. Subotica, SERBIA, pp. 207-215. 
11-Tabatabaiefar, H.R. and Massumi, A., 2010. “A simplified method to determine seismic responses of reinforced concrete moment resisting building frames under influence of soil–structure interaction”. Soil Dynamics and Earthquake Engineering, 30(11), pp.1259-1267.
12-Nguyen, H.D. and Shin, M., 2021. Effects of soil–structure interaction on seismic performance of a low-rise R/C moment frame considering material uncertainties. Journal of Building Engineering, 44, p.102713.
13-Ghannad, M.A. and Jahankhah, H., 2007. Site-dependent strength reduction factors for soil-structure systems. Soil Dynamics and Earthquake Engineering, 27(2), pp.99-110.
14-Avilés, J. and Pérez‐Rocha, L.E., 2003. “Soil–structure interaction in yielding systems”. Earthquake engineering & structural dynamics, 32(11), pp.1749-1771.
15-Ahmadi, E., 2019. Concurrent effects of inertial and kinematic soil-structure interactions on strength-ductility-period relationship. Soil Dynamics and Earthquake Engineering, 117, pp.174-189.
16-Miranda, E., 1997, January. Strength reduction factors in performance-based design. In Proceedings of EERC-CUREe Symposium, Berkeley, CA.
17-Miranda, E., 1993. Site-dependent strength-reduction factors. Journal of Structural Engineering, 119(12), pp.3503-3519.
18-Veda, A.V. and Manchalwar, A., 2021, July. Response reduction factor based on geometric variation with soil structure interaction. In AIP Conference Proceedings (Vol. 2358, No. 1). AIP Publishing.
19-GARCIA, M.F., Bazan, J.L. and Fernandez-Davila, V.I., 2024 Parametric Evaluation of the Response Modification Factor R Considering Bidirectional Ground Motions. Available at SSRN 4770563.
20-El Janous, S.O.U.M.A.Y.A. and El Ghoulbzouri, A., 2024. Seismic Vulnerability of Irregular Reinforced Concrete Buildings Considering the Soil-structure Interaction. International Journal of Engineering, 37(1), pp.104-114.
21-Aydemir, M.E. and Ekiz, I., 2013. Soil–structure interaction effects on seismic behaviour of multistorey structures. European Journal of Environmental and Civil Engineering, 17(8), pp.635-653.
22-Ganjavi, B. and Hao, H., 2014. Strength reduction factor for MDOF soil–structure systems. The Structural Design of Tall and Special Buildings, 23(3), pp.161-180.
23-Eser, M., Aydemir, C. and Ekiz, I., 2011. Effects of soil structure interaction on strength reduction factors. Procedia engineering, 14, pp.1696-1704.
24-Lu, Y., Hajirasouliha, I. and Marshall, A.M., 2016. Performance-based seismic design of flexible-base multi-storey buildings considering soil–structure interaction. Engineering Structures, 108, pp.90-103.
25-ASCE7-16. 2022. Minimum Design Loads for Buildings and Other Structures. American Society of Civil Engineers.
26-Lysmer, J. and Kuhlemeyer, R.L., 1969. Finite dynamic model for infinite media. Journal of the engineering mechanics division, 95(4), pp.859-877.
27-FEMA, 2009, Quantification of Building Seismic Performance Factors, FEMA P-695, prepared by Applied Technology Council for the Federal Emergency Management Agency, Washington, D.C.
28-Ganjavi, B. and Hao, H., 2014. Strength reduction factor for MDOF soil–structure systems. The Structural Design of Tall and Special Buildings, 23(3), pp.161-18.
Advance Researches in Civil Engineering
Volume 6, Issue 2
Spring 2024
Pages 27-38