| Title |
Seismic Load Evaluation and Design Spectrum Enhancement for Steel Structures Considering Soil Dynamics |
| Authors |
김동관(Kim, Dong-Kwan) ; 김동욱(Kim, Dong-Wook) |
| DOI |
https://doi.org/10.5659/JAIK.2024.40.9.209 |
| Keywords |
Seismic Load;Design Response Spectrum;Site Amplification Factors;Seismic Design Codes;Site Response Analysis;Steel Structures |
| Abstract |
This study evaluates seismic loads on various steel structures, taking into account amplified ground motions due to different soil conditions.
Seismic design codes define ground motions that induce inertial forces during earthquakes through the design response acceleration spectrum.
The 1985 Mexico earthquake highlighted the significant impact of soft soil amplification on seismic loads, leading to severe damage in midand
high-rise buildings and prompting the introduction of site amplification factors. However, the current Korean seismic design code (KDS
17 10 00: 2024) classifies ground without considering dynamic characteristics, resulting in discrepancies between actual and design response
spectra. This research analyzes three soil conditions with different dynamic properties, conducting site response analyses to derive surface
ground motions. Twelve steel structures of varying shapes (R-shaped, L-shaped, T-shaped) and heights (4, 8, 12, 16 stories) were examined.
By comparing seismic loads from amplified ground motions with those from the design spectrum, the study suggests improvements to the
seismic design spectrum. The findings indicated that the proposed spectra (PS-1, PS-2, PS-3), which account for dynamic site characteristics,
more accurately predict structural responses than the current KDS-S4 spectrum. Seismic base shear varied by up to 55% depending on site
conditions. The proposed spectra enhance design efficiency for structures on short-period (Site-1) and intermediate-period (Site-2) sites. For
long-period sites (Site-3), the amplification between modes was less pronounced, underscoring the need for comprehensive ground response
analyses to ensure safe designs. The study highlights the importance of revising the design response spectrum to reflect diverse ground
conditions, improving structural safety and performance predictions. |