Settlement monitoring of shallow foundations in collapsible tropical soil

The presence of collapsible soils poses a significant risk for foundation pathologies and is prevalent in various parts of the world, including tropical regions. This paper evaluates the behavior of a specific tropical collapsible soil through laboratory tests and field monitoring of foundations over the course of one year. Laboratory results indicate that the soil has a high collapse potential, particularly at stress levels exceeding 200 kPa, where it is considered critically problematic. Field monitoring revealed that external columns experienced settlement increases of up to 2.7 mm following rainfall events. In contrast, internal columns or those protected by concrete surfaces exhibited less seasonal variation in settlement, with changes of around 1 mm. These observations highlight that long-term exposure to moisture can result in undesirable settlement and underscore the need for moisture considerations in foundation design for collapsible soils. Structures that are initially loaded and subsequently exposed to moisture are likely to experience accelerated future settlement, potentially leading to structural pathologies. Therefore, consideration of moisture effects is critical in foundation design to mitigate long-term settlement issues.