Studies on the relationships between the local topography and the damages of buildings hit by Typhoon - Model test of topography used boundary layer wind tunnel -

我们已经分析了多年来风力对地形的影响。运用统计方法，分析了台风对建筑物的破坏分布与风速、风向等气象观测数据的关系。为了获得基础数据，我们在千叶县富措市的Myogane海角进行了风洞试验、有限元数值模拟和现场气象观测。在本研究中，我们得到了以下结论：1.简化地形模型的风洞试验。(1)阐明了不同坡度(坡度为10、15、30、45、60)上的风流分布规律，提出了风速增量系数S(X/Le，H/Le)的分布图(其中括号表示上风向坡长Le对山顶X和离地面高度H的函数依赖关系)。(2)分析了风速比(V/Vo；Vo为入射平均风速)与距山顶距离(Lx)或高度比(H/Ho：Ho为丘陵高度)之间的关系。(3)利用有限元方法，给出了不同坡度下的旋涡发展、转移和压裂条件。将现场气象观测数据与Myogane海角的模型风洞试验数据进行了对比。(1)明确了北风和东南风时风向和风速的分布情况。(2)提出了地形模型实验的CATHEN方法。

We have analyzed the topographical effects of wind forces for many years. Using statistic meghod,we analyzed the relationship between the damage distribution of buildings resulting from typhoon and it's meteorological observation data such as wind velocity and direction. However these methods are limited and obtaining available design data concerning the topographic effects is difficult.To obtain the basic data,we carried out wind tunnel tests,unmerical simulations on the finite element method and site meteorological observations at Myogane Promontory,Futtsu City,Chiba Pregecture. In this study, we obtained the following conclusions.1.Wind tunnel tests on the simplified topographic model. (1) We clarified the wind flow pattern over the various angles of the inclination of hills (slope angles ; 10 ,15 ,30 ,45 ,60 ) and proposed a distribution map of wind speed increment coefficient S(X/Le,H/Le)(where the brackets denote functional dependence on the position frow the crest X and the heigh above ground H in terms of the upwinf slope length Le). (2) We also analyzed the relationship between the wind speed ratio (V/Vo;Vo is the incident mean wind speed) and the distance from the crest of hills(Lx)or the height ratio (H/Ho:Ho is the height of hill). (3) Using the finite element method, we showed the growth and transfer of vortex and belamination condition over the various angles of the inclination of hills.2. Comparing the site meteorological observation data with the model wind tunnel test data at Myogane Promontory. (1) We clarified the distribution condition of wind direction and wind velocity when winds blew in northerly and southeasterly directions. (2) We proposed cartain methodology regarding topography model experiments.