基于结构全寿命设计需求的冻融作用谱模型与参数

Model and parameters of freeze-thaw action spectrum for the needs of structural life-cycle design

冻融作用谱模型应由年平均冻融循环次数和不同冻结温度的冻融循环发生概率分布两者组成。从结构全寿命设计需求考虑,依据全国130余个气象站点1951-2010年的温度数据,对我国冻融循环的发生概率分布进行分析。以日最高温度高于0℃,最低温度低于-3℃为冻融循环发生条件,选用(左)半边正态分布对哈尔滨地区温度数据进行分析,编制该地区的冻融作用谱,同时利用北京、呼和浩特、伊宁和郑州等典型地区的气象数据检验半边正态分布的适用性;最后给出我国主要地区的冻融作用谱参数,并对混凝土结构的冻融损伤预测进行举例分析。结果表明:我国绝大多数地区的冻融作用谱都能用半边正态分布表示;所提方法能够清楚描述我国各地区冻融作用的实际强弱情况,也可直接为进行结构全寿命期的性能退化预测提供所需的冻融作用参数。

The model of freeze-thaw action spectrum should include the annual average number of freeze-thaw cycle and the occurrence probability distribution of freeze-thaw cycle at different frozen temperatures. Due to the structural life-cycle design requirements, the probability of freeze-thaw cycle in China were analyzed employing the temperature data of more than 130 meteorological stations from 1951 to 2010. The freeze-thaw action spectrum of Harbin was drawn through data fitting with the （left） half normal distribution, under the freeze-thaw cycle occurrence condition of daily maximum temperature higher than 0℃ and the minimum temperature lower than -3 ℃. The weather data of Beijing, Hohhot, Yining and Zhengzhou were investigated as well to verify the applicability of the half-normal distribution. At last, the parameters of freeze-thaw action spectrum of the main regions of China were given, and an express of freeze-thaw damage prediction of concrete structures were also given. Results show that the half normal distribution is suitable to method proposed herein could describe the compile freeze-thaw action spectrum for most areas of China. The strength of freeze-thaw action clearly, and could provide modelparameters directly for the need of prediction of structural life-cycle design.