Determination of wind speed and associated loads over the sports facility collapsed during the severe windstorm of 24 January 2009 in Sant Boi de Llobregat (Barcelona)

he severe windstorm of 24 January 2009, caused by an explosive cyclogenesis, affected coastaland precoastal areas of the northeast of the Iberian Peninsula, where damages were numerousand significant, both in urban areas and in forests. One of the most important effects was thecollapse of a sports facility in Sant Boi de Llobregat (10 km southwest of Barcelona), killingfour children. The objective of this study is to estimate the wind speed over the sports facilityand calculate the suction of the wind on the roof of the building, and the consequent collapse ofthe walls. To get a first approximation, a simulation of the episode around the time of maximumwind gust was inspected using the mesoscale model MM5. In the second part, the damage aroundthe collapsed facility was analyzed, with which we note the fact that a truck was dragged andknocked over by the wind. This analysis allows for the conclusion that, in conjunction with themaximum wind gust, there was a sudden and very local shift in the wind, which caused the gustto hit the building head on. Based on this observation, the wind speed on surface and at 7 m(roof of the building) was estimated, and the suction of the wind was calculated.