GTR Review Checklist for Retaining Structures

E. Retaining Structures

 (See "Earth Retaining Structures" FHWA NHI-99-025)

In addition to the basic information listed in Section A, is the following information provided in the project geotechnical report?

1. *Recommended soil strength parameters and groundwater elevations for use in computing wall design lateral earth pressures and factor of safety for overturning, sliding, and external slope stability.
   
       (Yes   /   No   /   Unknown or N/A)

2. Is it proposed to bid alternate wall designs?
   
       (Yes   /   No   /   Unknown or N/A)

3. *Are acceptable reasons given for the choice and/or exclusion of certain wall types?
   
       (Yes   /   No   /   Unknown or N/A)

4. *Is an analysis of the wall stability included with minimum acceptable factors of safety against overturning (F.S. = 2.0), sliding (F.S. = 1.5), and external slope stability (F.S. = 1.5)?
   
       (Yes   /   No   /   Unknown or N/A)

5. If wall will be placed on compressible foundation soils, is estimated total, differential and time rate of settlement given?
   
       (Yes   /   No   /   Unknown or N/A)

6. Will wall types selected for compressible foundation soils allow differential movement without distress?
   
       (Yes   /   No   /   Unknown or N/A)

7. Are wall drainage details, including materials and compaction, provided?
   
       (Yes   /   No   /   Unknown or N/A)

Construction Considerations

8. Are excavation requirements covered including safe slopes for open excavations or need for sheeting or shoring?
   
       (Yes   /   No   /   Unknown or N/A)

9. Fluctuation of groundwater table?
   
       (Yes   /   No   /   Unknown or N/A)

Top-down Construction Type Walls

 (See "Manual for Design & Construction Monitoring of Soil Nail Walls", FHWA SA-96-069R and "Ground Anchors and Anchored Systems", FHWA IF-99-015)

10. *For soil nail and anchor walls are the following included in the geotechnical report?

    1. Design soil parameters (φ, c, γ)
       
           (Yes   /   No   /   Unknown or N/A)

    2. Minimum bore size (soil nails)?
       
           (Yes   /   No   /   Unknown or N/A)

    3. Design pullout resistance (soil nails)?
       
           (Yes   /   No   /   Unknown or N/A)

    4. Ultimate anchor capacity (anchors)?
       
           (Yes   /   No   /   Unknown or N/A)

    5. Corrosion protection requirements?
       
           (Yes   /   No   /   Unknown or N/A)

*A response other than (yes) or (N/A) for any of these checklist questions is cause to contact the appropriate geotechnical engineer for a clarification and/or to discuss the project.