Characteristic functions of regional soils: difference

As one of the core contents of regional soil theory and methods, empirical analysis and evaluation method research on the differences in N–vs characteristic functions of regional soils are conducted. The quantitative evaluation results of the measured differences in N–vs characteristic functions currently available in the world are proposed, and evaluation methods for the differences in N–vs characteristic functions in different regions are established in this paper. The N–vs characteristic functions of sandy soils from 42 different regions in 13 countries and the N–vs characteristic functions of clay soils from 22 different regions are collected and organized, forming 1092 sets of comparative working conditions. Through analysis, the statistical characteristics and general rules of the differences in the measured N–vs characteristic functions in different regions are revealed. The results show that the measured N–vs characteristic functions in different regions of the world mostly have significant or above differences, with extremely significant differences accounting for more than one-third, and no difference in engineering significance does not exceeding 10%. Using 41 sets of N–vs function relationships as samples, formulas for calculating the probability and level of differences in N–vs characteristic functions of sand and clay in different regions are constructed, and all existing data are verified. The results of this study empirically support the concept that the N–vs function relationship can be used as a characteristic function of regional soil, and elevate the understanding of soil properties with regional characteristics from intuitive to rational. At the same time, it also provides technical means for analyzing the differences in soil properties in different regions.