Subgrade moisture content forecast based on probability of precipitation

The correlation between subgrade water content and precipitation in Tacheng and Altay was analyzed, to determine the range of subgrade water content with different precipitation probabilities. According to the statistical analysis of historical data of precipitation, precipitation intervals with different reliabilities were calculated by interval estimation method. Humidity sensors were buried to observed the subgrade water content and precipitation in the same period, then the subgrade water content with different precipitation probabilities were obtained by establishing the functional relationship between subgrade moisture content and precipitation. The results showed that, there was a good correlation between subgrade moisture content and precipitation. The precipitation interval were [14.8,19.6], [15.2,19.2] and [15.4 , 19.0] when reliability were 95%, 90%, 85% The subgrade water content intervals were [3.97,4.31], [4.01,4.28] and [4.02,4.27] with precipitation probability of 95% 90% 85%.