ReSSA Major Update and MSEW Update

Here’s a press release from Rensselaer about their students winning the MSE wall competition at the Geo-Frontiers conference. Congratulations guys! [Source: Rensselaer via ASCE SmartBrief. Image: RPI]

[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.

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[Correction] Whoops, I think it’s North America’s tallest MSE Wall, not the world’s. Anyone know what the World’s tallest MSE wall is? [/Correction]

TheNewsTribune.com has an interesting article on the Sea-Tac third runway project and how it is nearing completion and an overview of the hurdles faced. This was a unique project from a geotechnical perspective because in order to construct the runway, North America’s tallest MSE retaining wall at 130-ft high was built. One thing I didn’t know is that the 13 million cu-yd of fill needed to construct the runway needed to pass careful inspection to make sure it was free of contaminants and similar in mineralogical composition to the on-site materials. The implications and reasoning are explained in this quote from the article:

“We had to find gravel that originated in the same place in Canada and that was transported here by the glaciers as the gravel that was here on the site,” said King.

The reasoning behind such a requirement is that water that leached through the fill would pick up minute traces of the minerals in the fill, drain into the creeks and confuse or damage native salmon returning to those creeks.

By way of ASCE SmartBrief. 

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