- Follow provided guidelines for optimum project organization that define roles and responsibilities for the various parties involved in retaining wall design and construction.
- Retaining wall design should be done during the design phase of the project by a design professional working directly for the project owner or owner’s representative and not be procured by the retaining wall contractor during the construction phase.
- Global and Compound Stability must be evaluated.
- The SRW components consisting of the face unit, soil reinforcement, and soil, must meet basic industry standards.
- Taller walls require special considerations including tighter standards for the reinforced soil.
The SRW design should be performed during the design phase of the project with the SRW designer as part of the design team. At the onset of the project, the SRW design engineer and site civil engineer should meet with the property owner to understand how the site will be used, project timeline and aesthetic objectives. Everyone on the team should also have an understanding of any special considerations, including local codes or ordinances, unusual site conditions and project relation to existing structures or utilities.Other issues that will impact design include existing site drainage and topography, surface water, soil characteristics, property lines, and proposed locations of structures, roads and utilities. The owner or site civil engineer should contract with a geotechnical engineer to obtain a report on soil characteristics, groundwater conditions, applicable seismic coefficients and applicable foundation remediation needs. Site access constraints may also exist that will impact construction or staging and should be discussed in the planning phase.
The full evaluation of geosynthetic reinforcement materials is very important, yet very complex. Fortunately, a third-party review system is already in place to verify the strength properties and QC standards of reinforcement materials through the National Transportation Product Evaluation Program (NTPEP). Therefore, a best practice is to only use geosynthetic reinforcements with a current NTPEP report.