Soil Nailing – Aremedial construction technique to improve natural soil slopes, retaining walls, and embankments quality.

11 Jul

This geotechnical engineering process comprises the insitu reinforcement of soils and have wide range of applications for stabilizing excavations and slopes. The technique involves the insertion of relatively slender reinforcing elements; often general purpose reinforcing bars (rebar) although proprietary solid or hollow-system bars are also available into the slope(fig. shown below) .

installation of reinforce bars into slopes.

Installation of reinforce bars into slopes.

the slope after the installation of the slender bars.

the slope after the installation of the slender bars.

First, the site condition for the construction of the soil nailing is examined. The examination includes the study of soil type condition, ground water level, and slope type. Also the cost parameter for the construction of soil nailing is determined. The most favorable conditions for soil nailing are as follows: The soil should be able to stand unsupported one to two meters high for a minimum of two days when cut vertical or nearly vertical. Also all soil nails within a cross section should be located above the groundwater table. Based upon these favorable conditions for soil nailing stiff to hard fine-grained soils which include stiff to hard clays, clayey silts, silty clays, sandy clays, and sandy silts are preferred soils. Sand and gravels which are dense to very dense soils with some apparent cohesion also work well for soil nailing.
These parameters determines the feasibility of the soil nailing walls. For soil nailing bars are installed using drilling techniques, are usually fully grouted and installed
at a slight downward inclination with bars installed at regularly spaced points across the slope face as shown in above fig.
After this the slope is grouted as shown in fig below:

Grouting of the slope.

Grouting of the slope.

In this way natural soil slopes are improved. The clear figure of the soil nailing of the natural slope is given below:

Stabilization of soil slope by soil nailing.

Stabilization of soil slope by soil nailing.

In this way we can stabilized the natural slopes. This could be the better technique for the soil stabilization which have wide application in countries like France, America, etc.