Lateral Earth Pressure

At-rest / active / passive Rankine resultants with surcharge & water table.

Soil strength values (c, φ, γ, lateral-bearing) must come from a project-specific geotechnical report — the pre-filled defaults are illustrative placeholders, not safe assumptions.

Design diagram — updates live with your inputs

Wall & Backfill

Wall condition

Wall height H (ft)

Soil Properties

Friction angle phi (deg)

Soil unit weight (pcf)

Surcharge (psf) Uniform on backfill

Water table depth (ft) Below top of wall; large = none

IBC 2021

Validation, assumptions & limitations Download validation report (PDF) ↗

This calculator is verified by 4 independent tests comparing its output against closed-form statics, NDS/SDPWS design-standard values and published worked examples. Full case-by-case results are in the PDF report.

Assumptions

Level backfill, vertical wall face, cohesionless soil (c=0).
Soil triangle acts at H/3, surcharge rectangle at H/2 above base.
Below the water table the buoyant unit weight is used for soil.

Limitations

Soil phi and gamma are geotechnical INPUTS — confirm with the soils report.
No cohesion, sloping backfill, wall friction or seismic increment.
Rankine (not Coulomb); passive assumes full mobilisation.

Results are for preliminary design and must be confirmed by a licensed engineer against the current adopted code and project-specific conditions.