Hollow-Core Soil Nails State-of-the-Practice

Document Info

Title: Hollow-Core Soil Nails State-of-the-Practice

Authored By: Naresh C. Samtani, PE, PhD, Edward A. Nowatzki, PE, PhD

Sponsoring Agency: Office of Bridge Technology, Federal Highway Administration



A commentary on the use of hollow-core bars for soil nail walls is presented in this report based on the authors’ experience. The basic technology of hollow-core soil nailing is presented and several issues related to that technology are raised. Topics for further study are recommended. Some guidance is provided on how to proceed with the use of the hollow-core nail technology until the issues are studied in detail. It is recommended that along with the evaluation and resolution of the various issues, the FHWA should develop a construction inspector manual that applies to the hollow-core nail technology. Preliminary guidance for construction monitoring and QC/QA is also provided in this report.

Memo from FHWA

The following is a reproduction of the memorandum from Jerry A. DiMaggio, P.E., the Principal Bridge Engineer – Geotechnical in the Office of Bridge Technology at the FHWA. The memo can also be found embedded in the SOP document.

Date: June 8, 2006

Subject: INFORMATION: FHWA Hollow-Core Soil Nails State-of the-Practice Report, April 2006

From: Jerry A. DiMaggio, P.E., Principal Bridge Engineer – Geotechnical, Office of Bridge Technology, FHWA

To: FHWA National Geotechnical Team Members

FHWA is interested in the hollow core soil nail technology and would like to see hollow core nails used on transportation projects where they would add value. We believe that the technology is different enough from the traditional drill-and-grout soil nail that study is needed to develop specific hollow core soil nail guidelines. FHWA is interested in developing such guidelines and in collaborating with others in doing so.

With this interest in mind, FHWA is pleased to provide a recently completed report on the current state of practice for hollow soil nail use on transportation projects. This report does not present FHWA guidelines, rather it summarizes the state of the practice and identifies areas where further study and guideline development would be beneficial… These areas can be broadly classified as follows: 1) determining capacity of test nails; 2) assuring quality of production nails, and 3) long-term performance. We plan to prioritize the study areas listed in the report and to look for ways to get the priority issues addressed and to develop published guidance on hollow core soil nail technology. We welcome your thoughts on priorities and ideas for collaboration.


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