Based on Stefan improved formula calculate the freezing depth of the standard field
This study is based on 600 meteorological stations distributed in seasonally frozen ground regions of China,the annual maximum freezing depth and temperature observation data were measured in the past 50 years from 1971 to 2020. In the 600 stations,the annual variation trends of temperature and freezing index were dis-cussed respectively. On the basis of Stefan improved formula,the statistical relationship between the Ea factor (based on temperature freezing index) and factors such as longitude,latitude and altitude were further explored on the standard field,and established an empirical formula. Using the empirical formula to calculate the Ea fac-tor,and verify the accuracy of it. The research shows that the Ea between the empirical formula and calculated by Stefan improved formula (based on temperature freezing index) have good fitting degree at most points,but some points at the boundary of permafrost regions have large fitting differences. In order to solve this problem,the research region was redivided into the general seasonally frozen regions and the transition regions at the boundary between the seasonally frozen regions and the permafrost regions. Correlation analysis was carried out respectively,and the relationship between the Ea and factors such as longitude,latitude,altitude were estab-lished. By comparing the observed values,it can be found that fitting degree of these points have been signifi-cantly improved. The correlation relationship was introduced into Stefan improved formula (based on tempera-ture freezing index) for further expansion,and finally getting the empirical formula based on temperature freez-ing's Stefan improved formula,which was used to calculate the freezing depth of the standard field in seasonally frozen ground regions of China. Since the E factor is relatively complicated to obtain,it is not easy to apply to engineering designs and constructions. For engineering construction sites where it is difficult to obtain the freez-ing depth,it calculated by using the empirical formula is similar to the observed values of meteorological sta-tions. The combination degree is highly,which can be better provide the freezing depth as a reference for engi-neering constructions.
万方数据
维普
