横风作用下坝体与心墙填筑高差的防风结构研究

Study on wind-proof structure with filling height difference between dam body and core wall under crosswind

为降低碾压式沥青混凝土心墙在强风下填筑时心墙施工区风速,使风力等级达到规范要求,提出了利用坝体与心墙填筑高差形成防风结构的方法对心墙处近地面风速进行消减,并通过现场试验和数值模拟的方法对横风下不同设计形式的防风结构风力消减效果进行了评估。结果表明:增加防风结构高差和减小设置距离有利于心墙处近地面风速的消减;8级风(风速20.7 m/s)条件下,防风结构设置距离为9.08 m时,高差为10 m和12 m的心墙处近地面风力可消减至4级风(风速5.5 m/s)以下;设置距离和达到防风要求的最小高差呈线性关系;风速和达到防风要求的最小高差符合二次多项式关系。

In order to reduce the wind speed to satisfy code requirement for the core wall construction area under strong wind,the method of wind-proof structure formed by height difference between dam body and core wall was proposed to reduce the wind velocity near the surface of the core wall.The effects of wind-proof structure with different arrangements were studied by field test and numerical simulation.The results show that increasing the height difference of the wind-proof structure and decreasing the setting distance are propitious to reduce the wind speed near the core wall.When the distance of wind-proof structure is set to be 9.08 m and the height difference is between 10 m and 12 m,the wind level 8(wind speed 20.7 m/s)can be reduced to less than level 4(wind speed 5.5 m/s)near the core wall ground.There is a linear relationship between the distance of the wind-proof structure and the minimum height difference to meet the wind-proof requirement.The fitting between the wind speed and the minimum height difference to meet the wind-proof requirement has a quadratic polynomial relationship.