Hirokazu MATSUOKA

A Study on Environment of Wind including Marine Salts around Bridge

Eiji IWASAKI, Masatsugu NAGAI

The amount of marine salts is measured to use the Weathering Steel, and it is assumed that it should be 0.05mdd(mg/dm2/day) or less. However, because the amount of marine salts changes through year, a large amount of labor and time are needed for the measurement. Therefore, the measurement of the amount of marine salts can be omitted in the region where the distance from seashore is seemed to be enough. In Niigata, the distance from seashore is 20km or more, so most of plain this prefecture become the research zones. It is important to forecast the amount of marine salts because this is hindrance to construct Weathering Steel Bridge. And, it is thought that it is useful to clarify the relationship between wind and geography, as well as marine salts.
This study aims to develop of a new technique of the forecast of the amount of marine salts.
The result of obtaining is described as follows.
1)It decides the direction of the prevailing wind with the observation point.
2)Because error of the forecast value and the observation value of the amount of marine salts is small, this forecast technique is advisability.
3)The flow of the wind changes by for the space under girder and the depth of girder and wind direction.