Wind loading on structure (1)

[35] Effects of Sealing Degree of a Building on Difference Pressure Force Caused by a Steep Decline of Atomospheric Pressure

○Tomohiro Izumi¹, Shunsuke Takahashi², Eriko Tomokiyo³, Junji Maeda⁴ (1.Kyoto University Graduate School of Enginering, 2.The Chugoku Electric Power Corporation, 3.Kumamoto Univirsity Graduate School of Science and Technology, 4.Kyushu University)

Keywords:Steep Decline in Atmospheric Pressure, Sealing of Building, Tornadic Load

A steep decline of atmospheric pressure by a tornado causes differential pressure force to a building and it is thought that the sealing degree of the building affects the intensity of the force strongly. Two mathematical procedures are known to estimate the differential pressure force. However their accuracy is not confirmed experimentally in a case of a strongly unsteady state such as a steep decline of pressure because of the difficulty of making it in a calm condition. This paper introduced the device of generating a sudden change of pressure acting to a building in a calm condition and studied the effects of the building sealing on the differential pressure force and the accuracy of the numerical results. Finally we showed the estimated wind speed of a tornado based on the damage situation is strongly affected by a rapid atmospheric-pressure descent as well as a tornadic wind speed.