FHWA’s MSE-LASR Manual Released!

The Federal Highway Administration (FHWA), through its Central Federal Lands Highway Division (CFLHD), retained NCS GeoResources, LLC (NCSG) to help develop a risk-based framework for the use of non-select (also referenced as “marginal”) fills for Mechanically Stabilized Earth (MSE) walls. A new FHWA MSE wall manual based on the study has now been released! This manual introduces a new MSE-LASR technology that provides guidance for design and construction of MSE walls using Local Available Sustainable Resources (LASR) which could be non-select fills.

This study was necessitated by the fact that use of select fill materials for MSE walls, while preferable, is not always practical because often such select fill materials are not available locally and must be imported to the job site. Also, the disposal of local native soils may be required with an associated cost that may significantly increase the total project cost. In such cases consideration is often given to alternative earth retention systems that have a larger carbon footprint, which is environmentally undesirable. These are significant issues that are encountered not only in the United States but worldwide. This groundbreaking work led to the development of “MSE-LASR” technology where LASR refers to Local Available Sustainable Resources. The framework for MSE-LASR technology considers the underlying risks associated with the use of such non-select fills and is indexed to the Load and Resistance Factor Design (LRFD) (i.e., limit states design) approach. The FHWA has just released the MSE-LASR manual. It was co-authored by Naresh C. Samtani and Edward A. Nowatzki. The manual can be found in the Downloads portion of this website.

Other News….

NCSG is also in the final stages of completing the work on the update of FHWA’s Soils and Foundations manual. As noted in an earlier blog, Naresh C. Samtani is the lead author and Jerry DiMaggio of ARA is the co-author. The new manual will be titled “Geotechnical Fundamentals for Transportation Projects.” Look for the new manual in the near future! The same two authors have also developed a new 2-day Instructor Led Training course for the FHWA on the topic of Drilled Shafts: Construction Procedures and Design Methods. The first (pilot) training is schedule to be delivered to the Oregon Department of Transportation in Salem, Oregon, on January 19 and 20, 2022.

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