Effect of frequency dependency of impedance functions on seismic damage index of soil-structure systems

Document Type : Original Research

Authors
H. Zahedi 1
B. Ganjavi 2
M. Bararnia 3
1 University of Mazandaran
2 Associate Professor, Department of Civil Engineering, Mazandaran University, Babolsar
3 PhD, Department of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran
10.22034/24.6.69
Abstract
In seismic analysis and design of conventional structures, it is generally assumed that the soil beneath the foundation is rigid and, thus, its flexibility is not taken into account. Soil flexibility can affect the response of structures through complex phenomenon of dynamics soil-structure interaction (SSI) effect. It is believed that effective soil and structural parameters could in some case significantly influence seismic response of structures in different manners and conditions. In this study, through an intensive parametric study, the effect of frequency dependency of impedance functions on constant-ductility damage index parameter of soil-structure SDOF systems subjected to ordinary strong ground motions were investigated. To this end, the soil-structure system was modeled by sub-structure method and the foundation was modeled as a homogeneous elastic half-space using the concept of the cone model. The soil-structure systems with shallow foundation were modeled based on various SSI key parameters, and were then analyzed under 15 earthquake ground motions recorded on soft soils.  Results of this study show that, in average, the maximum effect of excitation frequency dependency on seismic damage index is referred to the intensive SSI models, slender structures and with low level of inelastic behavior, which, in critical case, will occur in one or limited values of fundamental period. The maximum mean value is about 13.56% which cannot be considered as a criterion for practical application. Therefore, to have a logical criterion for practical purpose, the average values of entire periodic region in 15 earthquake ground motions were computed and, then, the maximum value, i.e., 5.76, was considered to make a decision. Overall, the results indicate that for soil-structure SDOF systems with shallow foundation, frequency dependency of impedance functions on damage index of structures subjected to earthquake ground motions would not have a remarkable effect and thus can be practically ignored in seismic analysis and design of soil-structures systems with shallow foundations. This finding being debated by researchers can lead to using a simple soil-structure system with less computational time and effort.

 

Keywords

Subjects

[1] Nakhaei M, Ghannad MA. The effect of soil–structure interaction on damage index of buildings. Engineering Structures. 2008 Jun 1;30(6):1491-9.
[2] Moghaddasi M, Cubrinovski M, Chase JG, Pampanin S, Carr A. Probabilistic evaluation of soil–foundation–structure interaction effects on seismic structural response. Earthquake engineering & structural dynamics. 2011 Feb;40(2):135-54.
[3] Ganjavi B, Hao H. Strength reduction factor for MDOF soil–structure systems. The Structural Design of Tall and Special Buildings. 2014 Feb 25;23(3):161-80.
[4] Ahmadi E, Khoshnoudian F. Near-fault effects on strength reduction factors of soil-MDOF structure systems. Soils and Foundations. 2015 Aug 1;55(4):841-56.
[5] Mirzaie F, Mahsuli M, Ghannad MA. Probabilistic analysis of soil‐structure interaction effects on the seismic performance of structures. Earthquake Engineering & Structural Dynamics. 2017 Apr 10;46(4):641-60.
[6] Khosravikia F, Mahsuli M, Ghannad MA. The effect of soil–structure interaction on the seismic risk to buildings. Bulletin of Earthquake Engineering. 2018 Sep;16:3653-73.
[7] Bararnia M, Hassani N, Ganjavi B, Amiri GG. Estimation of inelastic displacement ratios for soil-structure systems with embedded foundation considering kinematic and inertial interaction effects. Engineering Structures. 2018 Mar 15;159:252-64.
[8] Ganjavi B, Gholamrezatabar A, Hajirasouliha I. Effects of soil‐structure interaction and lateral design load pattern on performance‐based plastic design of steel moment resisting frames. The Structural Design of Tall and Special Buildings. 2019 Aug 10;28(11):e1624.
[9] Ahmadi E. On the structural energy distribution and cumulative damage in soil-embedded foundation-structure interaction systems. Engineering Structures. 2019 Mar 1;182:487-500.
[10] Eser M, Aydemir C, Ekiz I. Inelastic displacement ratios for structures with foundation flexibility. KSCE Journal of Civil Engineering. 2012 Jan;16(1):155-62.
[11] Lu Y, Hajirasouliha I, Marshall AM. Performance-based seismic design of flexible-base multi-storey buildings considering soil–structure interaction. Engineering Structures. 2016 Feb 1;108:90-103.
[12] Moghaddasi M, Cubrinovski M, Chase JG, Pampanin S, Carr A. Probabilistic evaluation of soil–foundation–structure interaction effects on seismic structural response. Earthquake engineering & structural dynamics. 2011 Feb;40(2):135-54.
[13] Lesgidis N, Kwon OS, Sextos A. A time‐domain seismic SSI analysis method for inelastic bridge structures through the use of a frequency‐dependent lumped parameter model. Earthquake Engineering & Structural Dynamics. 2015 Oct 25;44(13):2137-56.
[14] Tileylioglu S, Stewart JP, Nigbor RL. Dynamic stiffness and damping of a shallow foundation from forced vibration of a field test structure. Journal of Geotechnical and Geoenvironmental Engineering. 2011 Apr 1;137(4):344-53.
[15] Duarte Laudon A, Kwon OS, Ghaemmaghami AR. Stability of the time‐domain analysis method including a frequency‐dependent soil–foundation system. Earthquake Engineering & Structural Dynamics. 2015 Dec;44(15):2737-54.
[16] hyeon Chai S, Ghaemmaghami AR, Kwon OS. Numerical modelling method for inelastic and frequency-dependent behavior of shallow foundations. Soil Dynamics and Earthquake Engineering. 2017 Jan 1;92:377-87.
[17] Wang J, Lo SH, Zhou D, Xu BQ. Frequency-dependent impedance of a strip foundation group and its representation in time domain. Applied Mathematical Modelling. 2015 Jun 1;39(10-11):2861-81.
[18] Carbonari S, Morici M, Dezi F, Leoni G. A lumped parameter model for time‐domain inertial soil‐structure interaction analysis of structures on pile foundations. Earthquake Engineering & Structural Dynamics. 2018 Sep;47(11):2147-71.
[19] Ganjavi B, Mousavi SR. Influence of frequency-dependent dynamic soil stiffness and interacting parameters on elastic and inelastic response of soil-structure systems. Journal of Structural and Construction Engineering. 2019 Feb 20;5(4):57-75.
[20] Park YJ, Ang AH. Mechanistic seismic damage model for reinforced concrete. Journal of structural engineering. 1985 Apr;111(4):722-39.
[21] Jiang H, Fu B, Lu X, Chen L. Seismic damage assessment of RC members by a modified Park-Ang model. Advances in Structural Engineering. 2015 Mar;18(3):353-64.
[22] Diaz SA, Pujades LG, Barbat AH, Vargas YF, Hidalgo-Leiva DA. Energy damage index based on capacity and response spectra. Engineering Structures. 2017 Dec 1;152:424-36.
[23] Meek JW, Wolf JP. Cone models for homogeneous soil. I. Journal of geotechnical engineering. 1992 May;118(5):667-85.
[24] Mahsuli M, Ghannad MA. The effect of foundation embedment on inelastic response of structures. Earthquake Engineering & Structural Dynamics. 2009 Apr 10;38(4):423-37.
[25] Ghodrati Amiri G, Ganjavi B, Gholamrezatabar A. Evaluation of Drift Distribution in Steel Moment Frames Designed Based on Performance-Based Plastic design Approach Considering Soil-Structure Interaction Effects. Modares Civil Engineering journal. 2018 Sep 10;18(3):221-36.
[26] Pekelnicky R, Engineers SD, Chris Poland SE, Engineers ND. ASCE 41-13: Seismic evaluation and retrofit rehabilitation of existing buildings. Proceedings of the SEAOC. 2012 Sep.
[27] ICC. International building code. International Code Council, USA. 2015.
[28] OpenSees. Open System for Earthquake Engineering Simulation, Pacific Earthquake Engineering Research Center, Berkeley, Calif. 2016.
Modares Civil Engineering journal
Volume 24, Issue 6
November and December 2024
Pages 69-80