# Parametric Analysis of Outrigger Systems for High-Rise Buildings with Different Geometric Shapes
## 4 Conclusions  
This study provides a systematic investigation into the effectiveness of outrigger systems for enhancing the structural performance of tall buildings with both conventional and complex geometries. The findings clearly demonstrated the significant improvement in lateral stiffness achieved through outrigger implementation, evidenced by substantial reductions in fundamental periods, lateral displacements, and core base bending moments under wind-induced loads. The effectiveness of these systems was found to be highly dependent on the critical interplay between the building configuration, outrigger location, and relative flexural stiffness. While regular and tilted geometries showed significant performance gains with increasing outrigger-to-core stiffness ratios (up to 3%), twisted geometries experienced diminishing returns and reduced overall effectiveness beyond a 2\({}^{\circ}\) twist per floor. Notably, the benefits of increased outrigger stiffness plateaued beyond a ratio of 6%. Moreover, the results confirm that optimal outrigger placement is contingent on the specific design objective, with mid-height locations often providing a good compromise. Finally, the comparative analysis between the simplified and refined models underscored the importance of accurate belt-truss modeling. Refined models exhibited higher outrigger efficiency ratios, reflecting a more accurate representation of the overall structural behavior, especially regarding torsional stiffness. In general, the results confirmed the efficacy of outrigger systems for regular and moderately irregular buildings. However, the study also revealed that the inherent challenges of highly twisted geometries necessitate careful consideration of alternative or supplementary lateral load-resisting systems to ensure adequate structural performance. While this preliminary research provides a comprehensive parametric analysis of outrigger systems in tall buildings with varying geometric shapes under static wind loading, it is important to acknowledge certain inherent limitations. Firstly, the study primarily utilized simplified and linear elastic models to establish fundamental behavioral trends. Future investigations could explore the influence of non-linear material behavior and geometric non-linearities under extreme lateral loads. Secondly, while the impact of building geometry and outrigger configuration was extensively investigated within this initial scope, other relevant design factors such as core typology, variations in building height, and tapering of the core and column sections were not considered and warrant future research. Finally, the present parametric study aimed to establish the fundamental behavioral trends of outrigger systems using a simplified, uniformly distributed lateral load. Therefore, a formal sensitivity analysis examining the effects of non-uniform wind and seismic load distributions was not included within the scope of this initial investigation. Future work should address this limitation by exploring the response of outrigger systems under more complex and realistic loading conditions. Conceptualization, G.A. and E.C. ; methodology, G.A. and F.M. ; software, E.C. ; validation, G.A. and F.M. ; formal analysis, G.A. ; investigation, G.A. and E.C. ; resources, F.M. ; data curation, E.C. ; writing--original draft preparation, G.A. and E.C. ; writing--review and editing, G.A. and F.M. ; visualization, G.A. and E.C. ; supervision, G.A. and F.M. ; project administration, F.M. ; funding acquisition, F.M. All authors have read and agreed to the published version of the manuscript. [PERSON] and [PERSON] gratefully acknowledge the PNRR (Piano Nazionale di Ripresa e Resilenza) funding scheme as part of the National Research Centre CN1 on \"High-Performance Computing, Big Data and Quan-tum Computing\"--Spoke 5--Environment and Natural Disaster: Framework and methodologies for impact evaluation and risk mitigation\", Research Project No.CN1221844D08208F (Directional Decreation no. 1031 of 17 June 2022). Not applicable.