Geotechnical engineering is a branch of civil engineering that focuses on the behavior of earth materials. It involves studying soil and rock properties to ensure the stability and safety of structures like buildings, bridges, and dams. Geotechnical engineers assess ground conditions and design foundations that can support these structures effectively. This field also includes the analysis of potential hazards such as landslides and earthquakes. By understanding the interactions between structures and the geological environment, geotechnical engineers help prevent failures and ensure that construction projects are safe and sustainable.