An Analysis of the Bearing Capacity Ratio of the Cavitation-Prone Gypsum Soil

Gypsum soils, commonly found in semi-arid and arid regions, are susceptible to water exposure, which can lead to cavities that significantly reduce their ability to sustain loads. This research examines the impact of gypsum concentration, dissolution rates, and geometric parameters on the Bearing Capacity Ratio (BCR). Four soils with varying concentrations of gypsum and dissolution rates were investigated for both concentrated and eccentric load conditions using Finite Element Modeling (FEM). The results showed that increasing the L/B ratio (ratio of the horizontal distance (L) between the cavity center and foundation centerline to the foundation width (B)) improved the load distribution, especially for low-solubility soils, and reduced the effect of cavities on the stress distribution. However, soils with more significant dissolution rates, such as soil III (40% dissolution), did not perform well due to severe cavitation. The statistical analysis revealed that the soil type and dissolution levels were the most significant factors controlling BCR. The regression analysis enabled the creation of a predictive formula that incorporates essential factors, such as geometric ratios and gypsum dissolution. Soil I (0% dissolution) always exhibited greater BCR values, while soil III (40% dissolution) exhibited an extreme decline in BCR due to the extensive cavities formed by dissolution mechanisms. The soil without gypsum dissolution showed the highest bearing capacity ratio. Increased dissolution reduced the bearing capacity due to weakening caused by the formation of cavities. Increasing the depth-to-horizontal distance ratios improved the load distribution and bearing capacity, especially in soils with lower dissolution rates. The eccentric forces resulted in disparate strain rates adjacent to the load, thereby decreasing the bearing capacity in cavities nearby. Especially in settings with high gypsum concentrations, the study emphasizes the need to control the dissolution rates of gypsum and optimise geometric ratios in foundation structures. For designers seeking to forecast and mitigate foundation failure in gypsum-rich soils, the study provides valuable insights.