Seismic Retrofitting of a Building using Steel Bracing and Concrete Jacketing (with Case Study: A 5 Storey Building at Ibadan, Nigeria)
Downloads
Seismic retrofitting is a crucial intervention for enhancing the resilience of existing buildings in seismically active regions. This study focuses on the retrofitting of a three-storey commercial building in Ibadan, Nigeria, utilizing steel bracing and concrete jacketing techniques. Although Ibadan is not traditionally classified as a high-seismic zone, recent global and regional studies highlight the need to evaluate the potential impact of seismic loads on structures. This paper methodology entails retrofitting design, including assessment of existing structural conditions, selection of appropriate retrofitting techniques, numerical modelling using ETABS software, and a comparative analysis of retrofitted and unretrofitted models, also key structural response parameters such as base shear capacity, inter-storey drift, lateral displacement, and stiffness degradation were evaluated. The study further considers soil-structure interaction (SSI) effects, given the implications of seismic loading on foundation bearing capacity and ground settlement. The results expressed that retrofitting significantly enhances the structural integrity of the building, reducing lateral displacements and improving seismic resistance, and reveals that while the soil’s bearing capacity is sufficient under normal conditions, seismic loading could induce reductions in soil strength, emphasizing the importance of long-term ground improvement measures. The study concludes that steel bracing and concrete jacketing provide effective solutions for improving seismic resilience. Recommendations include implementing regular structural health monitoring, adopting performance-based design approaches, and considering soil stabilization techniques to ensure sustained structural stability under potential seismic events.
Afefy H M (2020), Seismic Retrofitting of RC coupled Shear Walls, A Review. Practice Periodical on structural Design and Construction, Vol 25 (3), Pp 1-12
Ayininuola g and Olalusi ) (2005), Assessment of Building Failures in Nigeria, Lagos and ibadan Case study. African journal of Science and Technology, vol 5 (1)
Badoux B M and Jirsa J O (1990), Steel bracing of RC Frames for Seismic Retrofitting. Journal of Structural Engineering, Vol 116 (1), Pp 55-74
Bansal J (2018), Structural Retrofitting in Historic Buildings the case of Hearst Greek Theatre, California. International Journal of Engineering and Technology, Vol 7 (1), Pp 1-7
Caterin N, Iervolino L, Manfredi G and Cosenza E (2009), Comparative Analysis of Multiple cretaria Decision-Making methods for Seismic Structural Retrofitting. Computer-Aided Civil and Infrastructure Engineering, Vol 24 (6), Pp 432-455
Chan C M, Ning F and Mickleborough N C (2000), lateral Stiffness Characteristics of Tall Reinforced Concrete Buildings under Service Loads. Structural Design of Tall Buildings, Vol 9 (5) Pp 365-383
Ercan C (2018), Assessing the Impact of Retrofitting on Structural safety in historical Buildings via Ambient Vibration Tests. Construction and Building Materials, Vol 164. Pp 337-349
Ferraioli M and Mandara A (2017), Base Isolation for Seismic Retrofitting of a Multiple Building Structure. Design, Construction and assessment. Mathematical Problems in Engineering, Vol 1, Pp 1-24
Geetha M and Chaitra D M (2021), Seismic Analysis and Retrofitting of an Existing Structure. International Journal of Research in Engineering and Science (IJRES), Vol 9 (8), Pp 29-39
Haikal C and Muca M (2018), Seismic Analysis and Retrofitting of an Existing Multi-Storey Building in Stockholm. KTH Royal Institute of Technology, Stockholm, Sweden
Kesner K and Billimgton S L 92005), Investigation of Infill Panels made from Engineered cementitious Composites for Seismic Strengthening and Retrofit. Journal of Structural Engineering. Vol 131 (11), Pp 1712-1720
Manisekar R (2018), Effect of External Post-tensioning in Retrofitting of rc beams. Journal of the Institution o engineers, India, Series A. vol 99 (3), Pp 495-501
Mayar K, Carmicheal D G, and Shen X (2023), Resilience and Systems – A Building Structure case example. Journal of Buildings, Vol 13 (6)
Miani A, Sezen H, Jalayer F and Prota A (2019), Performance-based Assessment Methodology for Retrofits of Buildings. Journal of Structural Engineering, Vol 145 (12).
Okagbue H I, Iroham C O, Peter N J, Owolabi J D, Adamu P I and Opanuga A A (2018), Systematic Review of Building failure and Collapse in Nigeria. International Journal of Civil engineering and Technology, vol 9 (10), Pp 1391-1401
Silva M J F, Almeida N M, Savado A F and Rodrigues H (2020), Modelling Structural Performance and Risk for Enhanced Building Resilience and Reliability. Journal of Innovative Infrastructure Solutions, Vol5 (1)
