The overall stability of slopes in the vicinity of walls is considered part of the design of retaining walls. The overall stability of the retaining wall, retained slope, and foundation soil or rock can be evaluated for all walls using limiting equilibrium methods of analysis. AASHTO gives the following requirements:
A minimum factor of safety of 1.3 shall be used for walls designed for static loads, except the factor of safety shall be 1.5 for walls that support abutments, buildings, critical utilities, or other installations with a low tolerance for failure. A minimum factor of safety of 1.1 shall be used when designing walls for seismic loads. In all cases, the subsurface conditions and soil/rock properties of the wall site shall be adequately characterized through in — situ exploration and testing and/or laboratory testing…
Prestressed anchors and anchor heads must be protected against corrosion that would result from ground and groundwater conditions at the site. The level of corrosion protection depends on both the ground environment and the potential consequences of an anchor failure. Also, anchors for permanent walls require a higher level of corrosion protection than those for temporary walls.
