Geotechnical investigations are studies conducted to assess the physical and chemical properties of soil and rock at a construction site. These investigations help engineers understand the ground conditions, which is crucial for designing safe and effective structures. Techniques often include drilling boreholes, taking soil samples, and performing laboratory tests. The information gathered from geotechnical investigations informs decisions about foundation design, slope stability, and potential environmental impacts. By analyzing the data, engineers can identify any challenges that may arise during construction and develop strategies to mitigate risks, ensuring the safety and longevity of the project.