Geotechnical Engineering is a branch of Civil Engineering. Geotechnical engineering uses the principles of soil mechanics and rock mechanics to investigate the subsurface condition, which helps in the design of the foundation for structures.
Geotechnical Investigation involves the process of drilling boreholes, taking soil samples, testing them in the laboratory, analyze the test report, and recommend a suitable foundation. The depth and number of holes depend on the area of the site and type of structure that will be built. Based on the soil report, a geotechnical engineer may recommend the improvement of the soil before any foundation can be built. The Geotechnical engineer also recommends the type of foundation, whether a deep foundation or shallow foundation is required. The foundation can be strip footing or pile foundation. The depth and type of pile are recommended based on the soil characteristic. Investigation of groundwater and investigation of rock, if encountered, also forms part of the geotechnical investigation report.