<p><p><h2>Preferred Design Procedure</h2>The FHWA Soil Nail Walls Geotechnical Circular No. 7 (Lazarte et al., 2015) is considered to be the design guidance document for soil nail structures in highway applications. However, this document does not include specific design guidance for screw-in soil nailing and is therefore not appropriate for this technology.</p><p>The Soil Screw Retention Wall System Design Manual (Collin and Cowell, 1998) provides design guidance specific to screw-in soil nailing. Based on a review of existing design methods, this is the most complete document for soil screws. The document is proprietary and intended for use with the A. B. Chance (CHANCE<sup>®</sup>) Company SOIL SCREW<sup>® </sup>Retention Wall System. The design manual is available for download at the website address listed in the references section. Table 1 shows typical inputs and outputs for design and analysis for screw-in soil nailing.</p></p>
<p><p><h2>References</h2>Bruce, D.A. and Jewell, R.A. (1986). "Soil Nailing: Application and Practice." Ground Engineering 19 (8) pp. 10-15, and 20 (1) pp. 21-38.</p><p>Byrne, R.J., Cotton, D. Porterfield, J., Wolschlag, C., and Ueblacker, G. (1998). “Manual for Design and Construction Monitoring of Soil Nail Wall.” FHWA-SA-96-069R.</p><p>Collin, J. G. and Cowell, M. (1998).<em> Soil Screw Retention Wall System Design Manual</em>, Hubbell/Chance, Centralia, MO. <a href="http://www.abchance.com/resources/technical/soilscrew_designman/home.ht…; target="_blank" rel="noopener">http://www.abchance.com/resources/technical/soilscrew_designman/home.ht…, C.A., Robinson, H., Gómez, J.E., Baxter, A., Cadden, A., and Berg, R.R. (2015). “Soil Nail Walls Reference Manual,” FHWA NHI-14-007, GEC No. 7, Federal Highway Administration, Washington, DC, 425p. <a href="https://www.fhwa.dot.gov/engineering/geotech/pubs/nhi14007.pdf" target="_blank" rel="noopener">https://www.fhwa.dot.gov/engineering/geotech/pubs/nhi14007.pdf</a></p><…;