| Title |
Nonlinear Time History Analysis of High-Rise Buildings Considering the Backstay Effect due to Basement Podium Structures |
| Authors |
황지우(Hwang, Ji-Woo) ; 김경태(Kim, Kyungtae) ; 김종호(Kim, Jong-Ho) |
| DOI |
https://doi.org/10.5659/JAIK.2025.41.10.301 |
| Keywords |
Slab Diaphragm; Backstay Effect; Nonlinear Time History Analysis; High-Rise Building |
| Abstract |
This study investigated the influence of basement podium slab diaphragm modeling on the Backstay Effect in tall buildings. Nonlinear time
history analyses were conducted with Rigid Diaphragm (RD) and Semi-Rigid Diaphragm (SRD) models. The investigation included
fundamental period, mode shapes, interstory drift ratios, shear forces in vertical members, diaphragm forces, and the distribution of seismic
loads among lateral force-resisting elements. Results indicated that the RD model caused significant local shear discontinuities in vertical
members at the Main Backstay Diaphragm level, which could lead to overly conservative designs. In contrast, the SRD model mitigated shear
force variations and produced smoother distributions. The SRD model also increased in-plane deformation of the podium slab, resulting in
longer fundamental periods and higher basement story drifts. The slab contributed substantially to lateral resistance, with diaphragm forces
accounting for 71.7% in the X-direction and 45.9% in the Y-direction. These findings highlight the importance of considering diaphragm
flexibility and accurately evaluating axial and shear forces in slabs and collectors during podium-tower structural design. |