SNAP-2 — The Complete Guide: Free Soil Nail Wall Design from FHWA
SNAP-2 (Soil Nail Analysis Program) from the US Federal Highway Administration (FHWA) brings soil nail wall design into one program — from the single nail to the stability of the whole slope. It is distributed as a free download, with no registration, for any purpose.
SNAP-2 (Soil Nail Analysis Program)
Federal Highway Administration (FHWA)
FHWA's soil nail wall design program – nails, facing, internal and external stability and global slope stability in a single package.
Get it from the vendorWhat you get
- Nail and facing checks — pullout resistance, nail strength and facing elements.
- Internal and external stability — sliding, overturning and bearing capacity of the wall.
- Global stability — limit-equilibrium analysis of the slope.
- Excavation stages — checking each intermediate construction stage.
- Field tests — assessing verification and proof test results, in US or SI units.
What to keep in mind
The calculations follow FHWA guidance, including GEC 7, rather than Eurocode 7 — on projects outside the United States check compliance with the applicable code. The program runs on Windows only, the latest version dates from 2016, and FHWA states explicitly that it provides no user support.
Related tools
For independent slope-stability analysis — SSAP. For earthquake-induced displacement — SLAMMER. For finite-element analysis of soil and wall — OpenSees.
SSAP — Slope Stability Analysis
Lorenzo Borselli, Università di San Luis Potosí
Limit equilibrium slope stability analysis, with automatic search for the critical surface.
Get it from the vendorSLAMMER
U.S. Geological Survey (USGS)
Sliding-block (Newmark) analysis of earthquake-induced slope displacement, with a built-in strong-motion library.
Get it from the vendor
OpenSees
Pacific Earthquake Engineering Research Center, UC Berkeley
Nonlinear and dynamic structural analysis driven by scripts, from the earthquake engineering world.
Get it from the vendor
pyStrata
Albert Kottke
One-dimensional seismic site response of a soil column — equivalent-linear, time series and RVT, in Python.
Get it from the vendorThe bottom line
SNAP-2 is a free, complete tool for soil nail wall design under the US approach — particularly useful for quick checks and comparison with commercial software.