Geospatial Analysis and Interpolation of Geotechnical Attributes for Development of Soil Geospatial Maps (SGMs) for Surat City, Gujarat, India

Accurate mapping of the geotechnical parameters poses a challenge for geotechnical and geological experts due to the limited level of investigation and inherent spatial variations. This study focuses on the development of Soil Geospatial Maps (SGMs) for Surat city, specifically addressing various characteristic geotechnical parameters such as soil type, SPT N value, cohesion, plasticity index, and field bulk density at depths ranging from 3 to 4 m. The emphasis on this depth range aligns with the construction of G + 2 to G + 3 buildings, where foundations typically lie within the 3 to 4 m depth in the study region. Consequently, these SGMs are anticipated to serve as a valuable tool for both practitioners and researchers. Sub-soil data utilized in this study were extracted from 105 geotechnical investigation reports. Statistical analysis of the dataset was conducted using descriptive statistics, incorporating measures of central tendencies and variances. SGMs were generated using the ArcMAP 10.7.1 module. The results reveal that, at depths of 3 to 4 m, the prevailing type of soil is medium to highly compressible clays. Additionally, SPT values range from 7 to 35, cohesion spans from 0 to 2.1 kg/cm2, plasticity index varies from 6 to 40, and field bulk density fluctuates from 1.65 to 2.76 gm/cc. The outcomes of this study are represented through comprehensive maps derived from an extensive database and hold significant utility for making informed decisions during the planning and design phases. This practice might prove to be an economizing factor in future projects.