Application of Weighted Overlay Techniques for the Identification of Areas Threatened by Expansive Soil Formation

This study proposes a methodology to assess the threat of expansive soil formation in Bucaramanga, Colombia, based on three main criteria: geotechnical properties, infiltrated precipitation (I), and temperature. The geotechnical criterion is determined using the Unified Soil Classification System (USCS) and Atterberg limits to assess plasticity and fines content. Infiltrated precipitation (I) is calculated using average monthly rainfall over the past ten years and an infiltration coefficient (C) that includes vegetation cover (kv), slope (kp), and soil texture (kfc). Temperature is considered for its impact on clay formation and adjusted for altitude. 101 soil samples were collected and analyzed, with climatic data from 2012 to 2022 also considered. Geographic Information Systems (GIS) were used to apply interpolation methods (IDW and kriging) to generate thematic maps and identify risk zones. By integrating these key factors, this methodology improves the accuracy of assessing the threat of expansive soil formation, providing a more reliable tool than traditional models. It is adaptable to other regions with similar conditions, offering valuable insights for predicting expansive soils in urban settings. The study highlights how temperature, soil properties, and precipitation infiltration influence risk, making this approach an effective tool for urban planning and risk mitigation, ultimately supporting better land management practices.