International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 05 | May -2017
p-ISSN: 2395-0072
www.irjet.net
Performance Analysis of Different Concentric Braced Frame Systems on an Irregular RCC Structure Imperiled to Wind Load Rahul Krishna K.R1, Avinash Kumar Sharma2, Ankush Kumar Jain3 1,2,3M.Tech
Student, Structural Engineering, Poornima University, Jaipur, INDIA ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract – With the upsurge in the tallness of the structure
2. Eccentric Braced Frame System- Entails braces positioned in the plane of the frame where one or both ends of the brace beams does not connects at the end points of other framing members.
surges the intensity & effects of Lateral loads comprising of seismic & wind loads. Wind load resistance becomes a governing factor once the structure achieves the description of tall structure due to the inefficiency of rigid or semi rigid frames to control the displacement & deflection thus reducing the strength & stiffness of the structure. Braced frame system is a highly competent & cost-effective method to control the deflections arising due to the fluctuating wind loads. In the present investigation three different types of concentric braced frame systems were analyzed in terms Shear force, bending moment, nodal displacement & reactions by using STAAD.Pro V8i software as per Equivalent static analysis method. An (G+11) irregular high-rise structure was assumed to be situated in Bhuj with Basic wind speed 50m/s
1.1 Building Description
For the analytical purpose a twelve storied (G+11) high-rise irregular RCC Structure with 6 bays of 4.2m along x direction & 4 bays of 4.2m along z direction was selected. The storey height of ground floor was taken as 6.48m while all other storeys were designed for 3.15m. The no bays along z direction first reduced after 8th storey & then after 10th storey. The structure was assumed to be located in Bhuj with Basic wind speed 50m/s.
Key Words: X type bracing, V type bracing, K type bracing, Shear force & node displacement etc. 1.INTRODUCTION
With the incessant growth in urban sprawl & desire to gain maximum profit with minimum investment has enthused the investor to look towards the sky. But with the rise in the height of the structure increases the surface area of the structure exposed to fluctuating wind load which persuades an extensive variety of comebacks in the structure as well as for the inhabitants residing inside it. Different types of lateral load resisting systems are accessible to control the deflections sourced by these wind loads. Braced frame system verified to be highly capable & cost-efficient compared to other wind load resisting systems as the bracing members are connected to form a vertical cantilever truss system which works in axial stress therefore necessitate minimum members to provide lateral stiffness & strength to the structure. Braced frame systems carries all the lateral loads thus, beams & columns are subjected to dead & live load only hence reduces the size & participation of beams & columns in load resisting exertion. Braced frame systems are broadly classified in two categories. 1) Concentric Braced Frame Systems 2) Eccentric Braced Frame Systems
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Impact Factor value: 5.181
OMRF
Number of Storeys
12
Type of Building
Residential
Location
Bhuj, Gujrat, India
No of Bays
x-6, z-4
Total Height
41.13
Basic wind speed
50m/s
Terrain Category
2
Class of Structure
B
Bracing Member
ISA 110x110x12
Size of Beam
230x420mm
Size of Column
300x450mm
Grade of Concrete
M-25
Grade of Steel
Fe-415
Table -1: Building Description
2. STRUCTURAL MODELLING & ANALYSIS
A twelve storey high rise irregular RCC structure subjected to wind load is analyzed with & without various braced frame system as per equivalent static analysis method by using STAAD.Pro V8i software. The braced frames analyzed are X type, V type & K type. The results are obtained in terms of Shear force, bending moment, node displacement & reactions. The bracings are provided along both x & y direction. Building is designed as per IS 456-2008 & wind load is
1. Concentric Braced Frame systems – Entails bracing members positioned in the plane of the frame. Both ends of the brace beams connects at the end points of other framing members to form a truss, creating a stir frame.
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