The best soil to use behind your segmental retaining wall is wall rock or select/structural fill with less than 10% fines, to the limits of the geogrid lengths. Sometimes on-site soils are acceptable to use as infill, be sure to check with the geotechnical engineer. Heavy clays or organic soils, and poorly graded sands or expansive clays should not be used in wall construction. Fine grained cohesive soils can be used, but additional backfilling, compaction and water management efforts are required. For more information on infill soil, consult Section 1 Part 2.3 in the Allan Block Spec Book. (ref. BP, Chapter 2.3)
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.