SOIL NAILING IN GEOLOGY INTRODUCTION Soil nailing is a ground reinforcement technique used to stabilize natural or excavated slopes, retaining walls, or deep excavations. It involves inserting steel bars (called nails) into the soil to increase its strength and prevent failure or collapse. The nails are usually drilled or driven into the slope and then grouted (cemented) to hold firmly within the ground. A facing (such as concrete or shotcrete) is often applied on the surface to protect the soil