In water applications such as retaining walls bordering detention ponds, global stability of the SRW system should often be analyzed. This is to assure that the adequate factor of safety exists for deep failures that pass behind the geosynthetic reinforcement and for compound failures that pass partially through the reinforced soil mass and partially behind the reinforced soil mass.
Whenever the groundwater is within two-thirds of the height of the wall below the bottom of the wall, this analysis should be run. If the cause for the global stability problems is weak foundations soils, it may be necessary for the geotechnical engineer on the project to do foundation improvements before the retaining walls are built.(ref. BP, Chapter 9.4)
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.