IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 09, 2015 | ISSN (online): 2321-0613
Seismic Analysis of a Multi-Storeyed Building with Irregular Plan Configuration Using ETABS N. Mohan Reddy1 Dr. E. Arunakanthi2 1 PG Student 2Associate Professor 2 Department of Civil Engineering 1,2 JNTU College of Engineering, Anantapur, Andhra Pradesh, India Abstract— It is an attempt to investigate the effect of Irregular plan configuration for multistoried reinforced concrete building model.This paper mainly emphasizes on analysis of a multi-storey building (G+25) which is irregular both in plan and elevation. Modelling of 25 storeyed R.C.C. framed building is done on the ETABS v13.2.0 software for analysis. Post analyses of the structure such as Maximum Storey Displacement, Base Shear, Storey Drift, Maximum base reactions, Torsion and Over-turning moments are computed and then compared for all the analysed cases. ETABS is an engineering software product that caters to multi-story building analysis and design. ETABS stands for Extended Three dimensional Analysis of Building Systems. Basic or advanced systems under static or dynamic conditions may be evaluated using ETABS. Design of steel and concrete frames (with automated optimization), composite beams, composite columns, steel joists, and concrete and masonry shear walls is included, as is the capacity check for steel connections and base plates. ETABS provides an unequaled suite of tools for Structural Engineers designing buildings, whether they are working on one-story industrial structures or the tallest commercial high-rises. Key words: ETABS, G+25, R.C.C I. INTRODUCTION Earthquakes are the most undesirable and distressing of all natural calamities. From this, it is very difficult to save the structural properties and life. To overcome these concerns, we need to find the seismic performance of the built environment by developing various analytical procedures, which safeguard the structures to withstand during numerous minor earthquakes and also provide enough caution at the time of major earthquake. The behavior of a building during an earthquake depends on several factors such as stiffness, adequate lateral strength, ductility, configuration etc... During an earthquake, buildings with regular geometry and uniformly distributed mass and stiffness in plan as well as in elevation suffer much less damage compared to irregular configurations. But in present days, need and demand of the latest generation according to growing population has made the architects or engineers inescapable towards planning of irregular configurations. II. OBJECTIVE OF THE STUDY To obtain the Seismic performance of an irregular building located in various earthquake zones and in different types of soils of India. III. SCOPE OF THE STUDY The Present work is focused on the study of Seismic demands of an irregular R.C building for various seismic zones and different types of soils in India. The configuration
involves plan irregularities such as diaphragm discontinuity, re-entrant corners and vertical irregularities such as geometrical irregularity, buildings resting on sloping ground. The performance was studied in terms of time period, base shear, lateral displacements, storey drifts and eccentricity in linear analysis using the code – IS1893 (Part 1):2002 . The entire modelling, analysis and design was carried out by using ETABS 13.2.0 version software. IV. IRREGULARITY The system of components of the building, which are able to resist the seismic forces, is known as lateral force resisting system (L.F.R.S). They are of different types. The most familiar forms of these systems used in a structure are special moment resisting frames (SMRF), shear walls and frame-shear wall dual systems. Generally, the damage in a structure initiates at a location where the weak planes are present in the building systems. These weaknesses activate further structural deteriorations, which leads to the structural collapse. These weaknesses often occur due to the presence of structural irregularities in stiffness, strength and mass in a building system. As per IS 1893:2002(part I), the structural irregularity can be broadly classified as, 1) Vertical irregularity and 2) Plan irregularity
(a) Classification of Structural Irregularity Here, we just focus on Plan irregularity and study the structural behavior of the structure with irregular Plan configuration. V. MODELING OF THE BUILDING In this study, entire analysis for all the 3D models has been done using ETABS 13.2.0 version software. The results are tabulated in order to focus the parameters such as Lateral Displacement, Base shear, Storey drift, Torsion and Base reactions acting on the building. Here, the entire analysis process is carried out by linear analysis.
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