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.