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Sand Backfill Calculator

Calculate structural sand backfill for retaining wall drainage zones, foundation perimeters, and utility excavation trenches.

Backfill Quantities

Real-Time
Cubic Yards (yd³)
0.00 yd³
Includes 15% compaction swell
Metric Tonnes
0.00 T
0 US Tons
Cubic Meters (m³)
0.00 m³
Compacted volume
Dump Truck Loads
0 Trucks
10-12 yd³ tandem truck
Visual Engineering

Retaining Wall Granular Backfill Wedge

Structural drainage envelope with compaction allowance and weep hole sub-drainage.

GRANULAR DRAINAGE WEDGE BACKFILL MATH • Wedge Vol = 0.5 × Base × H × L • Compaction factor: +15% • Weep hole: 4" perf pipe at base • Relieves hydrostatic water head

Retaining Wall Granular Backfill Wedge

Structural drainage envelope with compaction allowance and weep hole sub-drainage.

Mathematical Theory

Engineering Calculations & Formulas

Mathematical formulas and engineering constants powering this calculator.

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Triangular Wedge Volume

Calculates backfill volume behind vertical or battered retaining walls.

Wedge Vol = 0.5 × Top Width × Wall Height × Wall Length
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Compaction Surcharge

Adds 15% material allowance for mechanical plate tamper compaction.

Total Backfill = Geometric Vol × 1.15
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Dump Truck Haul Loads

Determines tri-axle dump truck deliveries needed for the backfill volume.

Truck Loads = ⌈ Backfill yd³ / 12 yd³ ⌉