<p><p><h2>Preferred Design Procedure</h2>The U.S. Forest Service (USFS) and Federal Highway Administration (FHWA) have provided guidance on shoot-in soil nail design in <em>Application Guide for Launched Soil Nails, Volume 1</em> (Myles and Stevenson 1994), based on information from a developmental project performed in 1992 (FHWA-FPL-93-004). The document gives a simplified design method specifically intended to select nail spacing to stabilize small road‑shoulder slides on low volume roads. The design procedure is based on a “best estimate” of subsurface conditions and does not require a geotechnical drilling exploration. As stated in the document, the simplified design approach is meant to be an “interim design method” that should be refined in the future. While the document does not serve as a complete and thorough design manual, preliminary design estimates can be obtained from the simplified methods prescribed within.</p><p>The 2015 updated <em>Geotechnical Engineering Circular No. 7 – Soil Nail Walls</em>, the FHWA standard for the design of(drilled and grouted) soil-nailed structures lists launched (i.e., shoot-in) nails as a similar technology, and notes the following. The bars are generally not grouted and, thus, this technology does not meet the definition of a soil nail presented in Chapter 1 of GEC 7. A launched nail acts as a dowel in the soil, and the contribution to stability is primarily by shear and associated, localized bending, and not primarily by tension as with a drilled and grouted nail. Launched nails develop limited axial capacity without grout.</p><p>Table 1 provides a list of typical inputs and outputs for design and analysis procedures for shoot-in soil nailing.</p><p><table class='tablepress' id='tablepress-312'><thead><th><center>Publication Title</th><th><center>Publication
Year
</th><th><center>Publication Number</th><th><center>Available for Download</th></thead><tbody><tr><td >Application Guide for Launched Soil Nails</td><td ><center>1994</td><td ><center>FHWA-FPL-93-003</td><td ><center>Yes<sup>1</td></tr></tbody></table><br><p class="disclaimer">¹ <a href="http://www.fs.fed.us/eng/pubs/pdf/em7170_12a.pdf">http://www.fs.fed.us/… more detailed information on the background, applicability, and design-method selection for shoot-in soil nails, please refer to the SHRP 2 R02 development project report <em>Shoot-In Soil Nailing Technical Evaluation Report</em>.</p></p>