# Launched Soil Nail

The Launched Soil Nail support type can be used to model launched soil nail slope reinforcement. Note:

• A Launched Soil Nail is generally a tube with a solid bar around it. However a solid bar can also be modeled by setting the appropriate parameters to zero.

• They are launched into the soil, and often used as a quick fix for slopes that are about to fail.

NOTE: make sure that you have read the Overview of Support Implementation topic, for important information which applies to all support models in Slide.

Out of Plane Spacing

The spacing between soil nails in the out-of-plane direction (i.e. along the slope).

Force Application

See the Force Application topic for a discussion of the significance of Active and Passive support force application in Slide.

Outer Tube

The outside and inside diameter of the outer tube and its yield stress are input here.

Inner Tube

The diameter of the outer tube and its yield stress are input here.

Resistance Type

Shear or Tensile resistance or both can be considered. These are explained below.

Shear Resistance

The vertical stress to the point of intersection of the soil nail with the surface is calculated: σ

Ultimate Moment Capacity is calculated for the tube and bar using the equations below:

Ultimate Lateral Bearing Capacity  is calculated using the equations below:

qu = σ Nq

And finally the Design Lateral Shear Capacity is calculated using the equation below:

Snail = 0.5 (2Mn qu  d)1/2

This value is divided by out-of-plane spacing and used as the calculated shear resistance.

Tensile Resistance

Allowable nail pullout resistance per unit length is calculated as:

T = ((bond strength)*Lo)/out-of-plane spacing