Soil nails are long, slender steel bars that are inserted into the ground to provide stability to slopes and excavations. They are typically used in geotechnical engineering to reinforce soil and prevent landslides or erosion. The nails are often grouted into place, creating a strong bond with the surrounding soil. The process of installing soil nails involves drilling holes into the soil, placing the nails, and then injecting grout to secure them. This technique is commonly used in construction projects, such as retaining walls and tunnel excavations, to enhance safety and support structures in challenging environments.