AASHTO LRFD Bridge Design Specifications – 2008 Interims Released
Available Resources
FHWA NHI 2009 MSE Wall Manual
[Disclosure] NCS Consultants is the employer (day job) of Randy Post, the owner of this site. [/Disclosure]
Geotechnical engineers who encounter MSE retaining walls or Mechanically Stabilzed Earth Walls are undoubtedly familiar with the FHWA NHI manual on “Mechanically Stabilized Earth Walls and Reinforced Soil Slopes”. This manual, along with the NCMA manual that is used for non-transportation projects, is virtually the bible for MSE wall design. In late summer/early fall of 2009, a revised version of this manual will hit the streets. Read on for more details.
Standards and Codes
Changes in Geotechnical Engineering Practice in Arizona
[Editor] Note: NCS Consultants, LLC is Randy Post’s full time employer…ie. my day job! [/Editor]
There are some significant changes being made to the state of the practice in geotechnical engineering in Arizona. NCS Consultants, LLC has prepared three policy memoranda for the Arizona Department of Transportation or ADOT that have been issued to consultants all over the State. These memos are on the topics of bearing capacity and settlement of spread footings and retaining walls, the design of drilled shaft foundations in gravelly soils, and the preparation of drilled shaft axial capacity charts for use by bridge engineers.
Although primarily applicable to upcoming ADOT projects implementing the AASHTO 2007 LRFD code, the memos will have a ripple effect down through other local agencies within the state who frequently defer to ADOT guidelines for geotechnical engineering. Also, the memos and the ADOT/NCS approach to LRFD implementation in geotechnical engineering were presented by NCS at the 2008 TRB Conference in Washington D.C., and many other state DOTs and the FHWA were very excited about the memos. The approach used if not the exact content may become a model for other agencies. More info and links to download the policy memoranda are provided after the break.
Articles
Side Hill Retaining Walls – Part 1
Side-hill retaining walls refer primarily to fill-walls built partway down the sides of an existing slope or embankment. They are encountered in roadway and rail widening projects as well as site development but usually in steep terrain. This article provides an overview of the problems, failure mechanisms, investigation approaches, analysis tools and wall type alternatives for these structures. Click through to read the article!