NCMA’s Design Manual for Segmental Retaining Walls

The importance of raw material certification is discussed in this article. The article also presents a real-life scenario that contains structural steel and outlines to engineers, specifiers and owners what is required in order to ensure the long term durability performance of polyester (PET) geogrids. This article discusses how a fundamental geotechnical-based method for structural stability, the National Concrete Masonry Association’s (NCMA’s) Design Manual for Segmental Retaining Walls, 3rd edition, has been instrumental in the growth of geosynthetic reinforced soil walls in commercial markets. NCMA has noted both Federal Highway Administration (FHWA) guidelines and American Association of State Highway and Transportation Officials (AASHTO) specifications in previous articles. These guidelines support the design of geosynthetic reinforced soil structures in public sector markets that include structures that are designed for state Departments of Transportation (DOT). Specifications and material testing requirements that are important to the long-term performance of geosynthetic reinforcement are provided in all of these documents and specific guidelines relative to the long-term disability of geogrid reinforcement manufactured from PET fiber are also included. With the use of geogrid reinforcement, mechanically stabilized earth (MSE) technology has been used to successfully construct segmental block retaining walls (SRW) that exceed heights of 80 feet and reinforced soil slopes (RSS) to heights of more than 240 feet. The article shows how the long term performance of these structures is directly related to the quality of the geogrid and, more importantly, the quality of the PET used to produce the geogrids. There are many different manufacturers of geogrid reinforcement in today's markets. Quality control and a quality product on the jobsite are achieved through material certifications.

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  • Authors:
    • Carter, Lance
    • Bernardi, Michael
  • Publication Date: 2014-2

Language

  • English

Media Info

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Filing Info

  • Accession Number: 01519189
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 11 2014 3:07PM