Wind effects on rectangular plan building located in a hilly terrain: A wind tunnel investigation

This paper presents a wind tunnel investigation of flow over symmetrical sinusoidal two-dimensional hills. A total of three hill models are tested which extend fully across the width of the wind tunnel in the direction perpendicular to the wind flow. The three hills have slopes equal to 15° (S1 hill), 30° (S2 hill), and 45° (S3 hill). Two independent studies are carried out: Wind flow characteristics study and Force measurement study. Wind flow characteristics study is carried out on the three hills and the results measured include mean wind velocity and turbulence intensity profiles. It is followed by a force measurement study carried out on a rectangular plan rigid building model which is placed near and on top of all the three hills at a total of 17 locations for each hill. Results measured include along-wind base shear forces and base moments. It is observed that the steeper hills (S2 and S3) have regions of high turbulence intensities extending beyond the crest region to a distance of 4H and 6H (where H is the hill height) respectively. The maximum average amplification factor for all the three hills is observed at the crest. The maximum along-wind base shear force for the building is reported to be highest for the shallowest hill (S1 hill) just upstream of the crest. Increased along-wind base moment for the building up to a factor of 5.5 is observed at the crest for S1 hill. This paper is expected to be of great help to structural engineers designing buildings in hilly terrains.