In this study, the structure of fluctuating surface pressure acting on a single fixed circular cylinder and a downstream circular cylinder of tandem circular cylinders were investigated by wind tunnel tests. Effects of the distance between the tandem circular cylinders on fluctuating surface pressure acting on a downstream circular cylinder of fixed tandem circular cylinders were investigated. As results of this study, it was found that the spatial correlation of fluctuating pressure on a downstream circular cylinder was affected by distance between the tandem circular cylinders. Furthermore, POD Analysis indicated that the structure of fluctuating surface pressure acting on a single fixed circular cylinder and downstream circular cylinder were different.
In Japan, criteria of Murakami et al and Wind Engineering Institute have been applied to the assessment in pedestrian wind comfort around buildings. However, these criteria do not considered wind danger conditions in which people can be blown over. Most foreign guidelines categorize wind comfort as well as wind danger. This paper examines various foreign guidelines regarding criteria for wind danger and discusses their applicability for assessment in a domestic project. Wind velocity observation records are re-examined and eighteen accidents near an observation site are discussed in relation to these records. It is thus shown that existing guidelines do not completely represent these eighteen cases. Thus, this study proposes new criteria related to blow-down accidents and wind observation records. For blow-down accidents, wind pressure against people is a better index than the wind velocity, and the new proposed criteria adopt a squared wind velocity value.