SOIL NAILING TECHNIQUES

SOIL NAILING TECHNIQUES

Soil nailing is a construction technique used to reinforce soil to make it more stable. Soil nailing is used for slopes, excavations, retaining walls etc. to make it more stable.

In this technique, soil is reinforced with slender elements such as reinforcing bars which are called as nails. These reinforcing bars are installed into pre-drilled holes and then grouted. These nails are installed at an inclination of 10 to 20 degrees with vertical.

Soil nailing is used to stabilize the slopes or excavations where required slopes for excavation cannot be provided due to space constraints and construction of retaining wall is not feasible. It is just an alternate to retaining wall structures.

As the excavation proceeds, the shotcrete, concrete or other grouting materials are applied on the excavation face to grout the reinforcing steel or nails. These provide stability to the steep soil slope.

These points must be noted for installation of soil nails:

1.Soil Nails must penetrate beyond the slip plane into the passive zone typically for 4 to 5m.

2.The spacing of soil nails in horizontal or vertical direction must be related to strength of the soil. Extra soil nails should be installed at the edge of any surface being stabilized.

3.Soil nailing should start immediately after excavation. Any delay may lead to collapse of soil slope.

EARTH WORK EXCAVATION IN LOOSE SOIL

MAKING ADVISABLE SLOPE

DRESSING SLOPE AREA

NAILING 2m 16mm STEEL ROD 500mm C/C SPACING

FIXING OF GI MESH OVER NAILING 16MM STEEL ROD AND WELDED WITH 8MM ROD HORIZONTALLY  

SPRAYING CHIPS MORTAR OVER LAID MESH

SPOUT PIPES FIXING

PROTECTED EXCAVATED EARTH