International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 11 Issue: 06 | Jun 2024
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p-ISSN: 2395-0072
Study on Steel & Concrete structure’s seismic performance with and without BRB (Buckling-Restrained Frame) Ankit Ladhani1, Milli Sankhla2 1M. E student, L.J university
2Professor, Dept. of Civil Engineering, L.J university, Gujarat, India
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Abstract – Steel & concrete constructions exhibit varying
robust vertical load strength and lateral force resistance. Buckling Restrained Braces (BRBs) are crucial for preventing compression-induced buckling. They exhibit balanced hysteresis loops, providing yielding behavior in compression and tension, thereby enhancing seismic resilience and protecting structures during earthquakes.
responses to earthquake forces depending on their design, which can range from minor cracks to complete collapse under severe shaking. In regions prone to seismic activity, many existing structures may not meet the current seismic code requirements for strength. The collapse of steel-concrete composite structures could jeopardize the safety and lives of occupants. Therefore, improving design to enhance seismic resistance is crucial, leveraging the inherent strengths of composite construction and effective methodologies. The design should prioritize energy dissipation, which plays a critical role in structural performance. Buckling-Restrained Braces (BRBs) are highly effective seismic resistance systems due to their ability to dissipate significant energy, making them suitable for both new lateral seismic loads and retrofitting existing structures. Linear and non-linear analyses using ETABS were conducted to evaluate the seismic performance optimization of a 10& 20-story steel and concrete structure incorporating single diagonal buckling restrained braces.
1.1 Buckling Restrain Brace The evaluation of the building's performance for this project will adhere to the guidelines specified in ASCE 41-06. Specifically, the focus will be on assessing the efficacy of Buckling Restrained Braced Frames (BRBFs) as the primary lateral force resisting system in both new construction and seismic retrofit projects. BRBFs represent a specialized form of concentrically braced frames distinguished by the incorporation of Buckling Restrained Braces (BRBs). These braces are engineered with a mechanism that prevents buckling, which is separate from the load-resisting steel core. This design effectively eliminates the potential for buckling failure modes by reducing the un-braced length of the compression member to zero. The core feature of BRBs is their ability to yield in both compression and tension, ensuring relatively uniform compressive strains compared to tensile strains. This characteristic significantly enhances the seismic resilience of the structure by facilitating controlled energy dissipation during seismic events while preserving structural integrity.
Key Words: BRB- Buckling Restrained Brace, Earthquake, ETABS.
1.Intoduction Earthquakes cause significant loss of life and property by collapsing buildings, especially impacting structural elements like beams and columns during intense seismic waves. Traditional lateral load resisting systems often fail under medium to severe earthquakes, prompting the introduction of buckling restrained braces (BRBs). These structural steel frames prevent buckling during seismic activity. BRBs comprise a steel core, bond-preventing layer, and outer casing. The core restrains axial forces with central yielding and rigid non-yielding parts at both ends. A bondpreventing layer allows core expansion and contraction during tension and compression, while the casing prevents buckling. Earthquakes result from sudden energy releases, such as geological faults, volcanic activities, landslides, or human-induced events like mine blasts. Dynamic seismic loads can swiftly collapse structures, causing significant harm. To withstand lateral forces from earthquakes and wind, buildings require bracing systems like shear walls that uniformly transfer these forces without compromising structural stability. Such lateral loads induce stresses, sway movements, and vibrations, necessitating structures with
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2. Problem Formulation This chapter outlines the building data used in this study, emphasizing the installation of Buckling Restrained Braces (BRBs) at the four corners of buildings to enhance seismic force control during earthquakes. The study examines various building structures, specifically 10 and 20-floor buildings located in Gujarat. DYNAMIC ANALYSIS OF BUILDING
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To Prepare 10 storey and 20 storey without BRB in RCC and Steel. To Prepare 10 storey and 20 storey with BRB in RCC and Steel. Analysis is performed by response spectrum Seismic Zone IV and V with Medium and Hard soil. RCC and Steel Structure without BRB
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