Risk assessment of settlement suitability due to soil collapse

Collapsible soils are widely found in many parts of the world, particularly in arid and semi-arid regions. These soils pose a potential threat to structures built upon them when they become saturated. Despite their naturally hard structure and high apparent shear strength in dry conditions, they can experience a significant reduction in volume upon contact with water. Exhibiting this characteristic even under very low stress levels, such soils are referred to as "collapsible soils." In this study, a pilot area within the boundaries of Şanlıurfa province, where caliches are predominantly exposed at the surface, was selected. A total of 61 soil samples were collected from the study area and subjected to experimental analyses. The consolidation characteristics of the soils were determined using one-dimensional oedometer tests, while the collapse potential was assessed based on data obtained from plastic limit, liquid limit, specific gravity, and unit weight tests. The evaluations revealed that the samples generally exhibited low to moderate collapse potential, with 80% of the samples classified as collapsible soils.