Abstract:

In this study, we analyzed the distribution patterns and ranges of expansive soil indices through an engineering case study in Ankang, Shaanxi Province. By utilizing mathematical statistical models, specifically the Normal, Gamma, Weibull, and Lognormal distributions, we aimed to gain a deeper understanding of these indices. To validate our findings, we conducted the Kolmogorov-Smirnov (K-S) test, which allowed us to confirm the distribution of the indices and further elucidate the physical and mechanical properties of expansive soil. Our results revealed notable trends: the dry density index exhibited minimal deviation with a right skew, closely aligning with the Normal distribution. Conversely, the expansion rate demonstrated the greatest deviation and a left skew, indicating its heightened sensitivity to other indices. We also observed that the Lognormal distribution adeptly captured the patterns of water content and void ratio, while the Normal distribution provided an accurate representation of dry density. The Weibull distribution, on the other hand, excelled in describing the distributions of liquid limit, plastic limit, plasticity index, expansion rate, and expansion force in expansive soil. When compared to the traditional average method, our approach by utilizing the peak parameter values from the optimal distribution functions of various indices offers a more precise evaluation of the physical and mechanical properties of expansive soil. The findings serve as valuable guidance for comprehending regional expansion deformation and enhancing engineering design and construction practices.

Key words: expansive soil, physical-mechanical indexes, distribution law, mathematic statistics, Kolmogorov-Smilov test