October 9, 2018

Best Practices for Zero Retaining Wall Failures - Proper Geogrid Orientation



Grid orientation can have a significant effect on strength, so it is crucial that you are sure it is being placed correctly. 
Typical commercial geogrid is uniaxial and strong in the roll direction and should be placed in sheets perpendicular to the wall facing.  If you are using biaxial grid, you don’t have to worry about this and grid can be rolled out in either direction.

If using uniaxial grid, cut geogrid to designed embedment length and place on top of the block units to within 1 in (2.5 cm) of the retaining wall face.  Extend away from wall approximately 3% above horizontal on compacted infill soils.  Placement of adjacent sheets of geogrid should be side-by-side without any overlap.

For dealing with corners and curves or to learn more about grid placement, Utilize Section 2 – Part 3.3 Geogrid Installation in the Allan Block SpecBook.  (ref. BP, Chapter 7.2)

Allan Block is working to achieve our industry initiative of Zero Wall Failures. With our Best Practices Manual and experience in the industry we are trying to expand the knowledge base for the design of segmental retaining walls (SRW's) by communicating and educating the professionals in the industry.  To see the full Best Practices Manual, visit allanblock.com to download today and keep an eye out for more industry Best Practice recommendations here.