Title |
A Study on the Estimation of Wind-duration under Strong Wind in Korea |
Abstract |
The wind resistant design of buildings generally used up to date has been based on the value of an extreme speed. The extreme speed is normally estimated from wind data observed for the return periods of 50 years or 100 years on the basis of the importance of building to be constructed. However, it is essential to consider the time variance of wind action because strong winds originated by Typhoon or others are occasionally coming for attack.This study is to examine the origin of occurence and the action time of strong wind, and to understand the time variance characteristics. Strong winds are divided into 3 parts such as the regional condition of Korea, namely Typhoon, Frontal system storm, and Monsoon. The areas reflecting the orgin of 3 kinds of the strong winds are also devided into 3 regions such as Seoul-Kyongki, Jungbu, and South-seashore. The representative cities are selected as Seoul for, Uljin and Kunsan for, and Busan and Yeosu for. Observed wind data of past 20 years will beemployed to estimate duration and propabillity of wind velocity.The observed wind data are recorded with duration of 96 hours at the center that annual extreme wind speed takes place, and with the mean value of wind velocity during 10 minutes at 1 hour interval.Based on these investigations, the duration and probability of wind velocity should be estimated. Generalized probability distribution function of wind velocity will be proposed. Duration of strong winds presented as a function of its maximum wind velocity. From these results, multipling generalized distribution function by generalized number of (wind velocity) samples, approximate equation of wind-duration will be derived. Approximate equation of wind-duration proposed in this study should be useful for analysing fatigue damage of structures and time dependent analysis of structure under strong wind in Korea. |