Lateral Earth PressureConstruction

Retaining Wall Rankine Lateral Active Earth Pressure & Overturning Moment Calculator

Calculate Rankine active earth pressure coefficient (Ka), resultant lateral thrust force (Pa in kN/m), and base overturning moment (Mo in kNm/m) with surcharge loading.

Calculated Result

Total Resultant Lateral Active Thrust (kN per linear meter)

37.71kN/m

Calculator Inputs

Quick select:
kN/m³
Quick select:
kPa
Quick select:

Total Resultant Lateral Active Thrust (kN per linear meter)

37.71kN/m

Total Base Overturning Moment (kNm per linear meter)

42.71 kNm/m

Rankine Active Earth Pressure Coefficient (Ka)

0.33 Ka

Soil Triangular Thrust Only (kN/m)

27.72 kN/m

Surcharge Lateral Thrust Component

9.99 kN/m

Soil Weight vs. Surcharge Thrust Breakdown

Soil Self-Weight Lateral Thrust
27.72 kN/m(74%)
Surcharge Lateral Thrust Component
9.99 kN/m(26%)

Rankine's classical theory assumes a vertical, frictionless wall backface with dry, free-draining granular backfill (c=0).

All engineering calculations, structural estimates, and electrical sizing metrics are provided for preliminary estimation only. Always ensure compliance with relevant statutory building codes and occupational safety standards, verified by a certified professional engineer before practical implementation.

Calculation Methodology

Ka = (1 - sin(φ)) / (1 + sin(φ)). Active Soil Thrust Pa = 0.5 * Ka * γ * H². Surcharge Thrust = Ka * q * H. Overturning Moment Mo = (Soil Thrust * H/3) + (Surcharge Thrust * H/2).

Frequently Asked Questions

A higher friction angle (e.g. 35° gravel vs 28° silty soil) significantly decreases Ka, reducing the lateral pushing force on the retaining wall.

Related Calculators

Recommended tools and calculators tailored to your current calculation

Explore all tools