Comparative Study on Wind Analysis of Multi-story RCC and Composite Structure for Different Plan Configuration

Abstract

The multi story high rise RCC structures are more bulky and less ductile in nature as compare to composite structures. This study investigates the comparison between RCC and composite structure under the effect of wind, additional to it composite structure also includes different plan configurations. In this study total fifteen number of building model are prepared and analysis for wind load by using ETABS 2015. The wind analysis is performed for different heights such 20m, 50m and 80m. In addition, the comparative study concludes that the composite structure are larger ductile in nature and more susceptible as compare to RCC structure and the composite option is better than RCC for multi story buildings. In addition, the comparison of different plan configuration shows that the response of parameter such as story displacement, story stiffness, base reaction and time period under effect of wind. The purpose of this analysis is to determine the most effective shape of structure in prone zone. The reinforced concrete structures are mostly used from many decades because of its stiffness, most convenience, high durability and ease to construct. The RCC structures are more suitable for low rise structure but for medium to high rise structures it is no longer economical because of large dead load, less susceptible, span restriction and complex formwork. So that, Structural designer is facing the problem of less susceptibility to lateral loads and also the problem of economy. The population of India is increasing day by day and they required land for living, for that multi story structures are best option for construction in metropolis cities where less land is available. Because multi story structure provides large floor area in small land area. Therefore, it is essential to construct high rise buildings. If high rise buildings are constructed than many structural problems arise, such as lateral load effect, lateral displacement and stiffness etc. Generally for high rise structure wind and earth quake load effects are dominant. Therefore for high rise buildings it is essential to have knowledge of various loads and its effect on buildings. The effect of lateral load is very important to consider such as earthquake and wind loads. In some cases the wind load is dominant than earthquake load which depends on area and zone factor defined by codes. Defining wind there are two aspects first one is beneficial which is to generate power and gives relief in hot and humid atmosphere and second one is parasitic which comes out to be factor consider for engineers. This wind effect will cause and produce wind induced motion in the structure. As high rise buildings push the envelope to greater heights, the structural designers are not only faced with problem to choosing a structural elements to carry the lateral load such as wind load and earthquake load but also insuring the design criteria that meets stability and serviceability requirement under complex wind environment. In addition, the high rise structures should meet more stiffness under lateral loads. Wind load act as lateral load on buildings which is act as along and across wind. In IS Code 875(Part 3)-1987, the basic wind speed are given in map and categorized by zones. The shape of buildings is very important in wind analysis, because the wind pressure is mainly depends on the exposed area of building against wind.