EFFECT OF PROXIMITY ON WIND LOADS ON RECTANGULAR PLAN TALL BUILDINGS

Abstract

Evaluation of wind induced loads is an important stage in the design of high-rise buildings and other structures. Efficient and economical structural system design for wind induced forces and deilections is required to ensure safety, serviceability and occupant comfort. If sufficient information is not available in wind loading codes to calculate wind forces, then these are obtained from the wind tunnel tests. Response of the structures are then calculated using the results of wind tunnel tests. Most of the standards on wind loads give the data (based on wind tunnel tests) for the isolated buildings. But due to modernization, scarcity and heavy cost of land, large number of high-rise structures are being constructed in groups. Wind flow gets disturbed due to shielding effect of these building constructed in the vicinity of each other. Wind induced pressure have considerable effect due to presence of any other structure in the proximity. There are little guidelines for wind load affected by building in proximity in standards on wind engineering, which a designer follows for assessment of wind loads. Although many studies have been done in the area of interference on wind loads on tall buildings, the researcher are yet not in a state to give generalized guidelines for the effect of proximity. The experimental study presented in this report gives a small contribution to this work. Number of interference setups are considered for force study. where base forces on building model are recoded for different spacing and compared with base forces on isolated building. Some of these forces are found to be reduced due to proximity effect and some of them get amplified. In some case forces are found to be reversed in nature. One of these case is studied further for pressure measurements for three spacings and three wind incident angles. To study pattern of loading contours of pressure coefficients on all sides are observed. Variation of pressure on all four sides is also studied for all cases and compared with isolated case to check the effect of proximity. The building considered in experimental study is modelled and analysed using STAAD PRO software for total twelve cases of wind loading obtained from pressure measurement study. The response of the building obtained for every interference case is compared with isolated case.