design alternatives (page 7)

Notes to the submission sheet on previous page:

1. Retaining wall to be constructed of Terraforce precast concrete blocks. (Type as indicated)
2. Blocks placed as shown and to be filled with well tamped topsoil.
3. For walls retaining clay or shale, provide a free draining sand layer behind wall. Backfill to be well rammed in 150mm layers.
4. Drainage outlet pipes to be provided at toe of slope to be capped with geotextile.
5. Stormwater cut-off drain is to be provided above the wall where necessary.
6. Ground under all bases to be approved granular material well compacted prior to constructing base.
7. The engineer is to be notified of any variations of levels or dimensions shown.
8. Minimum concrete strength for concrete foundations to be 20MPa at 28 days. (to be designed accordingly)
9. Shear Keys with a minimum design shear stress of 0,3N/mm² are to be installed as indicated.
   i.e. 75 x 75 mm 1:4 cement or crusher-sand mortar or 40mm H.D.P.E Class 6 pipe sections
10. No services or trenches permitted immediately in front of the retaining wall.
11. Maximum superimposed loading as indicated behind Wall. (surcharge)
12. Concrete keys to be class 1 mortar or 15Mpa concrete.
13. Please refer to the Terraforce construction manual and the guide to Terraforce L13 retaining walls for further detalls.
14. The Terraforce block retaining wall design spreadsheet can also be used to assist in the design process.