Retaining Wall Stability Calculator

Evaluate sliding, overturning, bearing, eccentricity, uplift, surcharge, groundwater, seismic, global, and preliminary structural performance using configurable assumptions.

Overall preliminary status

Fail

Fail

Governing checks use the selected safety factors and assumptions.

Stability dashboard

Governing results

Sliding factor
2.04
Pass Target 1.50
Overturning factor
4.23
Pass Target 2.00
Bearing factor
2.23
Fail Target 3.00
Eccentricity
0.099 m
Pass Kern 0.467 m
Global stability
1.54
Pass Screening only
Maximum base pressure
89.8 kPa
Fail Contact 100.0%
Visual model

Wall section and forces

H = 4.00 mB = 2.80 mEarth + waterWeight
Safety-factor chart

Calculated versus target

Project input

Configure wall and loading

Project and analysis mode

Version 1 stores calculation values in SI units.

Wall geometry

m
m
m
m
m
m
m
m
°
m
m

Soil, foundation, and interface properties

°
kN/m³
kN/m³
kPa
°
°
kPa
ratio
°
kPa
kN/m³

Layered-soil planning table

Use this table for project documentation. Convert layered profiles into representative design properties before calculating.

LayerThicknessUnit weightFriction angleCohesionNotes
Backfill 1
Backfill 2
Foundation

Surcharge and external loads

kPa
kN/m
m
kN
m
kN/m
kN/m
m

Available surcharge categories

Uniform traffic or storage surcharge
Strip and line loads
Point or equipment loads
Building foundation loads
Railway and construction loads
User-defined lateral action

Groundwater, drainage, and uplift

m
m
kN/m³
%
kPa
kPa
Check drained, blocked-drain, flood, perched-water, and drawdown scenarios separately. Drain efficiency directly reduces modeled net hydrostatic pressure.

Seismic loading

The built-in seismic coefficient is a preliminary approximation. Use a code-specific Mononobe–Okabe or displacement analysis for final design.

Safety criteria and bearing mode

kPa
kN/m³

Global stability screening

This module compares user-defined equivalent resisting and driving terms. It does not perform a complete slip-surface search.

kPa
°
kN/m
m
kN/m

Preliminary reinforced-concrete screening

MPa
MPa
m
ratio
ratio
The module screens stem-base flexure and shear only. Heel, toe, key, counterfort, anchorage, crack-control, development-length, and detailing checks remain required.

Scenario comparison and optimization


Detailed output

Forces and moments

ForceHorizontalVerticalApplication heightMoment about toe
Active soil thrust44.25 kN/m0.00 kN/m1.33 m58.99 kN·m/m
Uniform surcharge thrust12.29 kN/m0.00 kN/m2.00 m24.58 kN·m/m
Line load thrust0.00 kN/m0.00 kN/m1.80 m0.00 kN·m/m
Point load thrust0.00 kN/m0.00 kN/m2.00 m0.00 kN·m/m
Hydrostatic thrust0.00 kN/m0.00 kN/m0.00 m0.00 kN·m/m
Custom lateral force0.00 kN/m0.00 kN/m2.00 m0.00 kN·m/m
Wall seismic inertia0.00 kN/m0.00 kN/m2.20 m0.00 kN·m/m
Wall self-weight0.00 kN/m55.68 kN/m0.00 m66.43 kN·m/m
Soil over heel0.00 kN/m115.20 kN/m0.00 m230.40 kN·m/m
Vertical surcharge0.00 kN/m16.00 kN/m0.00 m32.00 kN·m/m
Vertical earth component0.00 kN/m20.58 kN/m0.00 m24.69 kN·m/m
Uplift0.00 kN/m0.00 kN/m0.00 m0.00 kN·m/m
Total driving force
56.5
kN/m
Total sliding resistance
115.6
kN/m
Net vertical force
207.5
kN/m
Resisting moment
353.5
kN·m/m
Overturning moment
83.6
kN·m/m
Passive resistance
5.3
kN/m
Bearing distribution

Foundation contact and capacity

Toe pressure
89.8
kPa
Heel pressure
58.4
kPa
Effective contact width
2.80
m
Resultant from toe
1.30
m
Ultimate capacity
763.3
kPa
Flotation factor
Not checked
Earth-pressure coefficients

Calculated coefficients and load components

Active coefficient, Ka
0.3073
Passive coefficient, Kp
3.2546
At-rest coefficient, K0
0.4701
Seismic active coefficient
0.3073
Soil thrust
44.2
kN/m
Hydrostatic thrust
0.0
kN/m
Structural screening

Stem demand summary

Stem base moment
83.6
kN·m/m
Stem base shear
56.5
kN/m
Required vertical steel
610,522
mm²/m, preliminary
Concrete shear capacity
236.0
kN/m, preliminary
Shear utilization
0.24
ratio
Structural status
Pass
screening only
Warnings and assumptions

Review before use

Formula used

Core calculation relationships

Pa,soil = ½ Ka γ H²
Pa,surcharge = Ka q H
FSsliding = Σ resisting horizontal forces ÷ Σ driving horizontal forces
FSoverturning = Σ resisting moments ÷ Σ overturning moments
e = B/2 − x̄, where x̄ = net moment ÷ net vertical force
qmax,min = V/B × (1 ± 6e/B), when full contact exists
qult = cNc + γDfNq + ½γB′Nγ

Remote surcharge, seismic, global, and structural modules use preliminary screening approximations. Verify those calculations independently.

How to use this calculator

Recommended workflow

  1. Enter the project title, wall type, and design basis.
  2. Define retained height, footing proportions, embedment, and optional shear key.
  3. Enter verified backfill, foundation, and interface properties.
  4. Select the earth-pressure method and define all surcharge loads.
  5. Model groundwater, drainage failure, water in front, and uplift.
  6. Enable seismic loading when the governing criteria require it.
  7. Set project-specific safety factors and bearing assumptions.
  8. Review force tables, contact pressure, warnings, and status labels.
  9. Save alternatives and compare governing load scenarios.
  10. Export the report for qualified independent checking.
Example data

Editable reference cases

CaseHeightBaseSoil φSurchargeWaterPurpose
Small cantilever4.0 m2.8 m32°10 kPa0 mTypical drained check
Blocked drainage4.0 m3.4 m30°10 kPa4.0 mHydrostatic sensitivity
Seismic wall5.0 m3.8 m34°12 kPa0 mPseudo-static screening
Sliding failure5.0 m2.2 m26°25 kPa2.0 mWarning demonstration
High bearing demand6.0 m3.0 m30°30 kPa0 mContact-pressure review
Load-combination planner

Recommended scenarios

CombinationEarthSurchargeWaterSeismicPassivePurpose
Normal drainedActiveServiceDrainedNoReducedRoutine long-term case
Blocked drainActiveServiceFull hydrostaticNoReducedDrainage failure case
FloodActiveServiceBoth sidesNoReducedNet water and uplift
SeismicSeismic activeCode valueSpecifiedYesProject rulePseudo-static check
ConstructionAt-rest or activeEquipmentTemporaryNoOften ignoredTemporary critical stage
Minimum verticalActiveNo favorable weightUpliftAs requiredReducedSliding and flotation
Design guidance

Understanding retaining wall stability

Retaining walls resist lateral soil pressure through wall weight and foundation resistance. Wall geometry controls stabilizing moments and foundation pressure. Soil properties influence every calculated stability check.

Sliding occurs when horizontal driving forces exceed available resistance. Base friction commonly provides the largest resistance component. Passive resistance should remain conservative and physically available.

Overturning compares stabilizing and destabilizing moments about the wall toe. The vertical resultant should remain within the permitted base zone. Excessive eccentricity creates partial contact and higher pressure.

Groundwater can govern an otherwise adequate retaining wall. Hydrostatic pressure increases rapidly with retained water depth. Uplift reduces effective weight, friction, and foundation contact.

Surcharge may come from traffic, stockpiles, buildings, railways, or equipment. Load position affects pressure magnitude and application height. Temporary construction stages can govern final wall proportions.

Seismic loading introduces soil and wall inertia simultaneously. Simplified pseudo-static methods support preliminary comparisons. Final work needs code-specific seismic analysis and displacement review.

External stability does not confirm concrete structural capacity. Stem, heel, toe, key, and counterfort reinforcement need complete design. Deep global failure may also govern the project.

Use verified geotechnical properties for final calculations. Compare drainage, flood, construction, and seismic scenarios independently. Professional review remains essential for safe construction.

Frequently asked questions

Retaining wall calculator questions

Does a passing sliding check prove the wall is safe?

No. Overturning, bearing, eccentricity, drainage, structural capacity, and global stability also require review.

Should passive resistance always be included?

No. Excavation, erosion, frost, utilities, or future grading may remove passive soil.

Why is groundwater important?

Water adds hydrostatic pressure and may create uplift beneath the foundation.

What does middle-third compliance mean?

It indicates the resultant remains within the central base zone for full compression.

Can cohesion reduce active earth pressure?

Sometimes, but permanent designs often neglect cohesion because it may degrade.

What bearing value should be entered?

Use a project-specific allowable pressure from a qualified geotechnical investigation.

Is the global module a complete slope analysis?

No. It is a screening comparison requiring independently determined forces and geometry.

Can this calculator design reinforcement?

It estimates preliminary stem demand only. Complete structural detailing remains necessary.

How should seismic coefficients be selected?

Use the governing standard, site hazard, wall behavior, and geotechnical recommendations.

Professional limitation

This application is an educational and preliminary design aid. It does not certify code compliance, construction suitability, geotechnical adequacy, or structural safety. Final retaining wall designs must be checked and approved by appropriately qualified professionals.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.