大跨悬索桥主缆温湿度长期监测与分布规律

Distribution and Long-term Monitoring of Temperature and Humidity of Xihoumen Bridge Main Cable

长期处于潮湿易腐蚀环境中的悬索桥主缆受到太阳辐射和空气对流的影响,很可能生锈断裂而影响大桥的安全。以西堠门大桥主缆系统为研究对象,为数值研究其温湿度变化机理提供物性参数,设计主缆室外温湿度监测试验。根据太阳运行轨迹提出了一种主缆太阳辐射模型,计算了不同工况日的年概率统计分布并对典型工况日的气温日变化函数曲线进行了拟合。研究结果表明:锚室内温湿度变化平稳,不易受外界环境影响,鞍座内温湿度变化剧烈,受外界环境影响较大;晴天工况下主缆温度受太阳辐射影响显著,而降雨/雪会使气温下降进而影响其太阳辐射规律。

The main cable of suspension bridge is exposed to highly humid and easily corrosive environment.Thus , corrosion defects are normally found developed on the main cable, which w o u l d e n d a n g e r t h e b r i d g efunctionality during its lifespan. The environment influence on the main cable system of the Xihoumen suspensionbridge was investigated. An in-situ long term monitoring of temperature and humidity of tlie main cable system isconducted to provide the physical parameters for the numerical study on the temperature and humidity variationpattern of the main cable. A solar radiation model of the main cable is established based on the trajectory of the sun. The temperature daily variation function is obtained for typical weatlier day based on yearly probability distribution. The results show that time t e m p e r a t u r e and h u m i d i t y in t h e a n c h o r ag e environment,while it is the opposite for the saddle room ; d u r i n g s u n n y time the main cable temperature is h i g h l y affected by the solar radiation, which could be changed by temperature drop due to rainy and snowy weather.