Correct form: Soil Retention by Nailing Method
Procedure for Soil Nailing (As per IS 14490:1997) Site Investigation & Design Conduct geotechnical investigation (IS 1892:1979) to determine soil properties. Nail length: 0.7 to 1.0 times excavation height. Nail spacing: Generally 1.0 m to 2.0 m horizontally & vertically. Inclination: 10°–20° below horizontal. Excavation Excavation should be carried out in stages of 1.0–2.0 m depth . Each stage should be stabilized with nails before moving further. Drilling of Nail Holes Diameter of hole: 100–200 mm (IS 14490 recommends 100–150 mm). Holes drilled using rotary percussion rigs with compressed air or water flush. Insertion of Reinforcement (Nails) Nails generally consist of TMT bars (as per IS 1786) or steel tendons. Centralizers to be used to maintain cover of ≥ 25 mm grout thickness . Grouting Grouting material: Cement slurry (IS 456 & IS 3370). Water–cement ratio: 0.4–0.5. Pressure grouting to ensure complete filling. Shotcrete / Fa...