Civil Insight: A Technical Magazine Volume 3 | Page 43

Dongol N. et al.
Civil Insight (2019) 37-44
3000.00
Reaction
2500.00
2000.00
1500.00
1000.00
FB
500.00
SM
0.00
0
100
200
300
Displacement (mm)
400
500
Fig. 7. Capacity Spectrum along the y-axis
4) Conclusions
The findings from this study demonstrate that the strategies for SSI modeling include spring-base modeling
and direct modeling for more realistic representation. It is observed that the base stiffness is decreasing due
to the consideration of soil parameters that reflect directly on the overall stiffness of the whole structure.
The following can be the major conclusions of this research:
x
x
x
x
Considering SSI, structures produce larger displacement, greater time period, and lesser base shear
in both directions.
Under pushover loadings on building, considering SSI, the base shear values are small as compared
to fixed-base system, which experiences an increase in roof displacement.
The effects of SSI are more pronounced in direct modeling in comparison to spring modeling
system of the building. However, the parameters may show different results according to their soil
conditions.
Taking SSI into account, there is more deflection of structures and hence structures undergo more
in tension. To counteract this, more reinforcement is needed, which is not presented in fixed-base
case. The SSI foresees the future damages in contrary to the fixed-base system; thus, the application
of SSI is quite advantageous for the long-term effects.
References
ATC-40 (1996). Seismic Evaluation and Retrofit of Concrete Buildings. Redwood City, CA: Applied
Technology Council
FEMA-356 (2000). Prestandard and Commentary for Seismic Rehabilitation of Buildings. Washington,
D.C: Federal Emergency Management Agency
Gerardo, B.G.L. (2017). Soil-Structure Interaction Effects on the Seismic Response of Low-Rise
Eccentrically Braced Frames (Masters Thesis). Retrieved from http://scholarworks.uark.edu/etd/2398
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