MAPPING EXPANSIVE SOILS BASED ON PHYSICAL PARAMETERS FOR FOUNDATION FAILURE RISK IN KUTA

Abstract

Kuta Village, located within the Mandalika Special Economic Zone (SEZ), has undergone rapid development, presenting challenges due to the presence of expansive soils. These soils swell and shrink with moisture changes, potentially causing structural damage and foundation failure if not properly managed. This study aims to map and assess the risks associated with expansive soils using physical soil parameters to support early mitigation efforts. Soil samples from 13 locations at depths of 30–50 cm were analyzed in the laboratory. The data were processed using ArcGIS 10.4, and a spatial distribution map was created using the Inverse Distance Weighted (IDW) interpolation method. Key soil parameters including liquid limit, plasticity index, activity, and expansion potential were evaluated. Soil behavior was classified using three established frameworks: the Seed, Chen, and Ladd & Lambe methods. Results indicate the Seed method provides a more conservative classification, while the Chen and Ladd & Lambe methods are more predictive. Despite differences, the classifications are generally consistent across methods. For practical application, the Chen method is recommended for initial screening, followed by Ladd & Lambe for field verification, and the Seed method for final validation and design. The study confirmed consistency in identifying high-risk zones, validating the reliability of spatial analysis in pinpointing areas susceptible to foundation failure. These insights offer a practical tool for guiding infrastructure planning and design to mitigate risks related to expansive soils and prevent structural damage.