基于路基湿度预估的综合湿度指数

Prediction based Subgrade Moisture Thornthwaite Moisture Index

摘要:

不同土组的路基湿度对路基路面结构工作性状与使用寿命均有显著影响，合理选取表征指标是路基湿度预估的关键.将路基湿度影响因素归并为气候与地下水位，引入气候因素表征指标——综合湿度指数，给出综合湿度指数定义，其计算分为潜在蒸发蒸腾总量计算、湿度平衡计算、年度湿度指数值计算，并给出具体算例.对计算得到的全国400个气象站点综合湿度指数值按照公路自然区划进行归并，认为所提出的综合湿度指数可作为公路自然区域划分的新指标.

Abstract:

Subgrade moisture has critical effect on performance of pavement structure and life of highway. Selection of indexes appropriately suggests influence factors are important for prediction of moisture. First, the factors of subgrade moisture were merged into climate condition and groundwater. Furthermore, thornthwaite moisture index(TMI), which comprehensively reflects influence of climate and latitude was introduced. Then, the calculation process of TMI was divided into three steps including calculation of potential evapotranspiration, moisture balance and calculating annual value of TMI. Moreover, example was presented to validate calculation procedure of TMI. Finally, values of TMI calculated on the basis of the meteorological data collected from 400 weather stations of China were tabled according to climatic zoning of highway. The results show that TMI can be used as new criterion to classify climatic zoning for highway.