In cases where there is a slope below a retaining wall or a “toe slope”, it may be necessary to bury more block than usual. Local ordinances commonly reference to bury enough blocks to have a 5 - 7 ft (1.5 - 2.1 m) level bench in front of the wall. Beyond this depth, there is a rule that requires an additional 1 in (2.5 cm) of block per 1.0 ft (30 cm) of wall height be buried.
In general when a slope below the wall is present, there is need for a global stability analysis to confirm the overall stability of the site. (ref. BP, Chapter 9.1)
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.