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Design table - Terraforce Terralite Block (L36)

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
87.8 70.9 55.3 40.7 26.8 13.3 0 mm setback
3.5 2.8 2.2 1.6 1.1 0.5 0 " setback
Firm clay
&
compact silt
0
 15.6 12.2 9.4 7.4 5.8 4.4 3.2 L36 block rows
2.4 1.9 1.4 1.1 0.9 0.7 0.5 meters
7.76 6.09 4.68 3.71 2.89 2.18 1.59 feet
10°
 12.3 9.9 7.8 6.0 4.5 3.6 2.9 L36 block rows
1.9 1.5 1.2 0.9 0.7 0.6 0.4 meters
6.15 4.93 3.90 3.02 2.27 1.82 1.43 feet
22°
 10.4 7.6 5.2 3.7 2.9 2.2 1.6 L36 block rows
1.6 1.1 0.8 0.6 0.4 0.3 0.2 meters
5.17 3.77 2.60 1.86 1.44 1.09 0.80 feet
 
Silty sand
&
sand
0°
 24.0 18.0 13.5 10.2 7.9 6.2 4.8 L36 block rows
3.6 2.7 2.1 1.6 1.2 0.9 0.7 meters
11.97 9.00 6.76 5.10 3.92 3.09 2.39 feet
10°
 21.4 15.7 11.5 8.4 6.6 5.1 3.8 L36 block rows
3.3 2.4 1.7 1.3 1.0 0.8 0.6 meters
10.7 7.84 5.72 4.18 3.30 2.55 1.91 feet
22°
 18.2 12.2 8.9 6.5 5.0 3.6 2.9 L36 block rows
2.8 1.9 1.3 1.0 0.8 0.6 0.4 meters
9.06 6.09 4.42 3.25 2.47 1.82 1.43 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