Soil nailing or (passive anchorage) is a flexible shoring system with shotcrete and it is constructed from top to the bottom in steps parallel to excavation.
The main elements of the system are soil nails, reinforced shotcrete surface cover and subhorizontal drains.
In case the system is designed as permanent, anti-corrosion PVC coat or epoxy-coated reinforcement, etc. are applied. Typically excavation surface is covered with wire mesh reinforcement in excavation steps of 1.5 m to 2.0 m in height, and the nails are connected to reinforcement wire mesh by means of a plate and nut. Afterwards final surface is covered with shotcrete and advanced to next excavation step.
Subhorizontal drains with perforated drain pipes are installed on the wall surface at vertical and horizontal spacing and lengths based on the design at excavation levels. The length and spacing of the nails are variable depending on the depth of the excavation, environmental loads and soil conditions, etc.
In this system, depending on the ground conditions after each excavation stage pre-shotconcrete is applied, followed by passive anchor drilling. Appropriate reinforcement is placed into the drill holes according to the design and the drill hole around the reinforcement is grouted with cement grout. Since the system can be constructed parallel to excavation shoring systems with a very flexible geometry can be achieved through construction.
