Recent forensic studies that investigated the failure of several Texas Department of
Transportation (TxDOT) soil nailed retaining walls revealed that incomplete grouting of soil
nails was a very common problem. This finding has raised serious questions about the
adequacy of QC/QA procedures currently used by TxDOT for verifying the integrity of
installed soil nails. The research study described in this report attempted to address these
concerns by:(a) developing of a nondestructive test method to check the integrity of soil …

This paper presents the findings from a research study that evaluated nondestructive test
(NDT) methods that may be useful for quality assurance purposes during construction of soil
nail retaining walls. More specifically, the new NDT procedure will be used to evaluate the
integrity of the grout column surrounding the steel tendon and to measure the grouted length
of the installed soil nail. A preliminary evaluation of the existing NDT methodologies was
undertaken to identify candidate NDT methods. The selected NDT methods, sonic echo and …