COMPARATIVE ANALYSIS OF BEARING CAPACITY METHODS FOR BATMAN SOILS: A GIS-BASED APPROACH

Akbulut N., KARABAŞ B., Tanyeri H.

Black Sea Journal of Engineering and Science, cilt.9, sa.3, ss.1386-1400, 2026 (TRDizin)

Özet

In this study, the spatial distribution of Standard Penetration Test (SPT) data and allowable bearing capacity calculations were evaluated for the central district of Batman, covering an area of approximately 54 km². Geotechnical data obtained from 253 boreholes were analyzed within a Geographic Information Systems (GIS) environment, and spatial prediction maps were generated for various depths (1.5, 3.0, 4.5, 7.5, 9.0, and 15.0 m) using the Inverse Distance Weighting (IDW) interpolation method. The allowable bearing capacities of the soils were calculated based on the empirical approaches proposed by Terzaghi and Peck (1967) and Meyerhof (1974), assuming a foundation width of 3 m. The analyses revealed that SPT-N values generally exhibit a linear increase with depth. At shallow depths, the northern and western parts of the study area—particularly near the Batman River (Girbereşik and Yeniköy)—are characterized by 'loose' to 'medium dense' soil formations, indicating low bearing capacity and potential settlement risks. The spatial distribution of bearing capacity showed that approximately 19% of the area has a low bearing capacity (< 163 kN/m²), 32% has a moderate capacity (163–325 kN/m²), and 49% presents a high bearing capacity (326–488 kN/m²). A comparison of the two analytical methods demonstrated a high degree of spatial compatibility; however, as depth and SPT-N values increased, the Meyerhof (1974) method yielded higher (more optimistic) bearing capacity values compared to the Terzaghi and Peck (1967) approach due to the influence of the depth factor. The GIS-based microzonation maps produced in this study provide a crucial spatial database for safe foundation design, urban planning, and earthquake risk mitigation in the region.