NTL Record

Title Hollow Bar Soil Nails Pullout Test Program
Record ID 68683
Personal Name
Creator
Cadden, Allen; Gomez, Jesus E.; Baxter, Andrew; Bird, Thomas
Personal Name
Contributor
Henwood, Justin; DeMarco, Matthew; Surdahl, R.; Anderson, Scott; Siel , Barry; Barrows, Richard J.
Corporate Creator United States. Department of Transportation. Federal Highway Administration. Central Federal Lands Highway Division
Corporate
Contributor
Schnabel Engineering; ADSC - The International Association of Foundation Drilling
Publisher United States. Federal Highway Administration. Central Federal Lands Highway Division
Publication Date 20100501
Language English
Abstract The use of Hollow Bar Soil Nails (HBSNs) is growing in the excavation support and retaining wall construction. It is anticipated that the use of the HBSN technology could reduce construction schedules, costs, and environmental impacts. The current state of practice for design bond strengths and load testing procedures is based on the current soil nail practice but varies depending on the installation contractor and product recommendations. The objective of this study was two-fold. The first objective was to develop an initial data file from installation and testing at four sites of the available grout-to-ground bond stress of HBSNs, and to determine if correlations exist with traditional solid bar, drill, and grout soil nails (for example, the published nominal values in FHWA-IF-03-017 [GEC No. 7]). The second objective was to establish recommendations for practical, standard ways of performing pullout tests on HBSNs. Comparisons between the pullout test results showed that the HBSNs generally developed larger bond strength values in granular soils than the Solid Bar Soil Nails (SBSNs). Three installation methods for purposes of pullout and proof testing were evaluated. Two were found to be to be satisfactory; however, the third one was noted to have a significant Doughnut Effect and was not recommended for pullout testing.
Public Note COTR: Justin Henwood, FHWA-CFLHD. Advisory Panel Members: Matthew Demarco and Roger Surdahl, FHWA-CFLHD; Scott Anderson and Barry Siel, FHWA-RC; and Rich Barrows, FHWA-WFLHD. This project was funded by the FHWA Federal Lands Highway Geotechnical Program, the FHWA Federal Lands Highway Technology Deployment Program, and the Association of Drilled Shaft Contractors – The International Association of Foundation Drilling.
Rosap ID dot:42934
Rosap URL https://rosap.ntl.bts.gov/view/dot/42934
TRT Terms Soil nailing; Pull out test; Soil stabilization; Field tests
General Subjects Hollow Bar Soil Nails; Load Testing; Soil Nails; Hollow Bar Micropiles
Geographical
Coverage
United States
Contract Number DTFH68-07-P-00092
Report Number FHWA-CFL/TD-10-001
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/68000/68600/68683/FHWA-CFL-TD-10-001.pdf
Format PDF
Database NTL Digital Repository