Identifying potential geo-hazards in Hingurakgoda area linked to damaged houses
Authors:   Department of Civil Engineering, University of Moratuwa, Sri Lanka, Thushyanthan S. , Nawagamuwa U.P. 
Published: October 2024

Expansive soils pose significant challenges for construction projects worldwide due to their dynamic response to changes in moisture levels. This study focuses on identifying and categorizing expansive soils in the Hingurakgoda region, using data from the National Building Research Organization (NBRO) alongside advanced analytical techniques. By examining key soil parameters such as Atterberg limits, clay content, moisture content, and swell pressure, the research aims to understand the underlying causes of structural issues affecting buildings in the area. Spatial analysis tools like ArcGIS and Google Earth Pro were utilized to develop effective methods for recognizing expansive soils and understanding their geological relationship with marble layer cavities. The presence of minerals like smectite, montmorillonite , and illite in expansive soils significantly influences their swelling and shrinking behaviors. The study thoroughly investigates the geotechnical aspects of the soil, revealing complex underground conditions such as alluvial deposits and karstic formations, which exacerbate the challenges posed by expansive soils. The research emphasizes the importance of accurately identifying and categorizing these soils to predict soil movement and potential structural damage effectively. By combining insights from extensive data analysis and geotechnical studies, the study offers valuable recommendations for minimizing risks associated with expansive soils, thereby enhancing the security and durability of structures in the Hingurakgoda region. In this study, six different methods were utilized to assess the swelling potential of expansive soils: Seed et al. (1960, 1962a), Ladd et al. (1961), Ranganatham and Satyanarayana (1965), Carter and Bentley (1991), Chen (1988), and Vander Merwe (1964). Among these methods, the Vander Merwe (1964) method demonstrated the highest level of similarity in predicting soil swelling potential The method’s consistent performance across various test results suggests that it is the most appropriate approach for classifying expansive soils in the Hingurakgoda area. The accuracy and reliability of the Vander Merwe (1964) method make it a valuable tool for evaluating soil expansiveness and managing associated risks, providing a strong foundation for construction and mitigation strategies in regions prone to soil swelling. To further build on these findings, future research should prioritize increasing the number of soil sampling locations in Hingurakgoda. Expanding the sampling distribution would lead to more comprehensive data, allowing for more accurate spatial mapping and improved predictions of swelling potential. This approach would enable a more precise identification of high-risk areas, contributing to better-targeted risk mitigation strategies. By adopting an enhanced sampling strategy, future studies can significantly improve the reliability of soil classification and provide more effective guidelines for construction practices in regions affected by expansive soils. In conclusion, the study's findings underscore the critical role of accurate soil classification methods, particularly the Vander Merwe (1964) method, in mitigating the risks associated with expansive soils and ensuring the long-term stability of structures in the Hingurakgoda region