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Design table - Terraforce L13 Block

Maximum wall heights (in block height, metres, feet) for a single skin, mass gravity, block retaining wall system - without additional interlocking keys, reinforcements or backfill stabilizing.

Retained Soil Backslope above crest
of retaining wall
Wall inclination from horizontal
  
60° 65° 70° 75° 80° 85° 90° inclination
129.9 104.9 81.9 60.3 39.7 19.7 0 mm setback
5.1 4.1 3.2 2.4 1.6 0.8 0 " setback
Firm clay
&
compact silt
0
 18.3 14.4 11.0 8.8 6.3 5.2 3.8 L13 block rows
4.1 3.2 2.5 2.0 1.4 1.2 0.8 meters
13.53 10.62 8.15 6.47 4.62 3.81 2.78 feet
10°
 14.5 11.7 9.2 7.1 5.4 3.3 3.4 L13 block rows
3.3 2.6 2.1 1.6 1.2 1.0 0.8 meters
10.71 8.60 6.80 5.26 3.95 3.17 2.50 feet
22°
 12.2 8.9 6.1 4.4 3.4 2.6 1.9 L13 block rows
2.7 2.0 1.4 1.0 0.8 0.6 0.4 meters
9.02 6.58 4.53 3.23 2.51 1.90 1.39 feet
 
Silty sand
&
sand
0°
 28.3 21.2 16.0 12.1 9.2 7.3 5.6 L13 block rows
6.4 4.8 3.6 2.7 2.1 1.6 1.3 meters
20.86 15.68 11.78 8.90 6.83 5.39 4.17 feet
10°
 25.2 18.5 13.5 9.9 7.8 6.0 4.5 L13 block rows
5.7 4.2 3.0 2.2 1.8 1.4 1.0 meters
18.61 13.66 9.97 7.28 5.75 4.44 3.33 feet
22°
 21.4 14.4 10.4 7.7 5.8 4.3 3.4 L13 block rows
4.8 3.2 2.3 1.7 1.3 1.0 0.8 meters
15.79 10.62 7.70 5.66 4.31 3.17 2.50 feet

  1. Wall height measured from top of foundation / levelling pad.
  2. Top of foundation / levelling pad a minimum of 150mm / 0.5 ft below ground level
  3. No allowance made for surcharge above wall
  4. Angle of internal friction used in calculations: P(firm clay)>26°,P(silty sand)>32°.
  5. Compaction effort at optimum moisture content to ensure maximum density achievable.
  6. Provided that groundwater conditions are controlled, a wide variety of soil types can be used for infill soil.
  7. Subsoil drainage is essential to intercept groundwater. Build-up of hydrostatic pressure and seepage forces minimised.
  8. Surface water run-off should be directed away from the wall