- Open Access
- Authors : Jerin Mathew Jose, Kesiya Josy V, Likhith Koruthe Varghese, Nayana P P, Adithya Viswambaran
- Paper ID : IJERTCONV9IS09025
- Volume & Issue : ICART – 2021 (Volume 09 – Issue 09)
- Published (First Online): 24-06-2021
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
Review of Analysis of Irregular Building
Jerin Mathew Jose1, Kesiya Josy V2, Likhith Koruthe Varghese3, Nayana P P4
1,2,3,4UG Students, Department of Civil Engineering Mangalam College of Engineering, Kottayam,India
5Assistant Professor, Department of Civil Engineering Mangalam College of Engineering,
AbstractThis paper deals with the review of structural behavior of irregular building for different plans like rectangular,C,L and I shape. Modeling of 15- stories RCCframed building to be a done on the ETABS software for analyze. maximum shear forces, bending moments, and maximum story displacement are computed and then compared for all the analyzed structure.
Keywords: – Irregular building, ETABS software, shear force, story displacement,story drift.
ETABS provides both static and dynamic analysis for a wide range of gravity, thermal and lateral loads. Dynamic analysis may include seismic response spectrum or accelerogram time history. This analysis mainly deals with the study of a rectangular, L, C and I shaped plan using ETABS.
The behaviour of any building depends on the arrangement of structures present in it.Irregularity in structures is alack of symmetry or eccentricity between geometry,mass,stiffness etc.Irregularities are introduced in real design for both aesthetic and utility.Irregularities in the distribution of mass, stiffness, and geometry along the height of the building grouped as vertical irregularities.The system having physical discontinuityis termed as irregular building.
A 32m x 24m 15- stories structure having 4m x 4m bays are modeled using ETABS. The height of each story is taken as 3m, making the total height of the structure 45m. Loads considered are accepted by the IS-875(Part1, Part2), IS- 1893(2002) code,and combinations are acc. to IS-875(Part5). Analysis of the structure, maximum shear forces, bending moments, story drift, and maximum story displacement, are computed and then compared for all the analyzed system.
Abhay guleria studied the structural analysis of multi-storey irregular building with different plans. It emphasizes on the structural behavior of multi-storey buildings for different plan configurationslikerectangular, C, L, and I shape. Help to give an idea about the story overturning moment varies inversely with storey height. Dynamic analysis, mode shapes are generated, and it can be asymmetrical plans undergo more deformation thansymmetricalplans. Modeling is to be done by using this journal.
SIVA NAVEEN E (2018) also studied the dynamic analysis of irregular buildings under earthquake loads.The structural behavior of multi -story frames with single and combination of irregularities.Help incorporating abnormalities in structures without compromising their performance the regular and irregular models. The Idea about the response spectrum analysis was conducted to clarify these models by taking the results of maximum displacement, inter-story drift, and story shear to compared. Response spectrum method allows a clear understanding of the contribution of different modes of plans.It is also useful for approximate evaluation of seismic reliability of structures.
From the above papers the problem, was learnt, analyzed and solved. Thispaper, focused on the dynamic analysis of an irregular buildings using grid slabs for different plan configurations. The topic which we are doing has very few articlespublished
A. Modelling of RCC frames
An RCC framed structure is an assembly of slabs, beams, columns, and foundations inter-connected to each other, as a unit. The load transfer mechanism in these structures is from slabs to rays, from beams to columns, and then,ultimately, from columns to the foundation, which in turnpasses the load to the soil. In this study, we have adopted four cases:
L-shape Plan c)I-shape Plan
Fig. 1: Plans of buildings
The building is 32m x 24m in plan with columns spaced at 4mfrom center to center. A floor-to-floor height of 3m is assumed.
Length x Width
No. of stories
Column 1-5 stories dimensions
Column 6-12 stories dimensions
Thickness ofthe main wall
Thickness of the parapet wall
Grade of Concrete
M30 fck= 30N/mm2
Grade of Steel
Response reduction factor
IS 875 (part 1)
IS 875 (part 2)
IS 875 (part 5)
The above table shows that the story displacement increaseswith the increase in story.
Fig.2 Displacement diagram
The above graph, it represents the graphical representation of the story displacement with different stories.
Fig. 3 shear force diagram
As per the above figure it has been concluded that the story shear decreases with the increase in story height.
Fig.4 story drift diagram
The above graph, it represents the graphical representation of story drift with various heights. It increases initially and decreases with increasing the height.
The above results show that, the displacement of building is increased with increasing the height but the shear force is decreased with increasing height and the story drift increasing
with increasing the height and reach the maximum point and slowly decreased with increasing the height.
Dynamic analysis, mode shapes are generated and it can be concluded that asymmetrical plans.
Validation of the software has been done by selecting suitable journal
Comparison of modal mass participation ratios was done usingETABS software. A very less variation was found
Comparison of story displacement values resultedin
The comparison of story drift value resulted in the difference of 1.27mm
The story shear results we obtained were nearly 2800kN.
COMPARISON OF RESULTS
The above table shows that the difference between journal structure and analytical structure.
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