温室基本风压取值方法探讨

Method for calculating basic wind pressure of greenhouse

风荷载作为温室主要活荷载,直接影响着温室结构的安全性和经济性.基本风压是计算风荷载的基础,在温室设计中,基本风压的取值长期以来沿用工业与民用建筑的荷载规范,存在许多不合理因素.2002年发布的<温室结构荷载规范>中对基本风压的规定与1987年的建筑规范完全相同,仍然未能体现温室这种特殊建筑的特征.该文根据温室特点对基本风压的取值方法进行了探讨,对<温室结构荷载规范>中基本风压所规定的重现期、风速测量高度、风速平均时距值进行了修正:将重现期由原来的30年改为5～30年,时距由10min改为瞬时～10 min,高度由10 m改为3～7 m,并根据部分地区的风速资料采用统计学中的极限概率模型--极值Ⅰ型分布模型计算出这些地区温室基本风压的修正值.

As the major load of greenhouse, the wind load directly influences the safety and economy of greenhouse structure. The basic wind pressure is the foundation for calculating the wind loads. However, before standard on greenhouse loads established in China, basic wind pressure was calculated by using industrial and civil buildings standards for a long time, and this was unreasonable. Regulation on the basic wind pressure in Greenhouse structure design load issued in 2002 is completely identical with industrial and civil buildings standards in 1987, and still fails to show this kind of characteristic of special building in the greenhouse. Based on the near two industrial and civil building load standards, the research on calculating method of basic wind pressure that fits the characteristic of greenhouse was carried out, and return period of basic wind pressure, time interval and measuring height of wind velocity in Greenhouse structure design load which is revised in 2002 were modified, and a few results were obtained by extreme value type Ⅰ function in statistics according to wind speed data of parts of cities.