It means to complete physical testing on the proposed site to understand the ground conditions for Geotechnical Design (foundations, retaining walls & soil improvement).
Soil Investigation is helpful in obtaining the information about the subsurface conditions at the proposed site where you dream of a construction. Investigation for Soil's Subsurface is essential for designing structures and planning construction techniques. Soil Investigation is basically done for big projects where we determine the engineering properties with the use of State-of-the-art Technology.