As retaining walls increase in height the active earth forces also increase in the lower portion of the wall. Therefore, you may want to consider in taller walls to increase the strength of the lower geogrid layers or decrease the grid spacing to accommodate the higher design forces. (ref. BP, Chapter 8.4)
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.