> ## Documentation Index
> Fetch the complete documentation index at: https://calcs.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Design a Restrained (Basement) Retaining Wall (IBC 2021)

> Design restrained (basement) retaining walls to IBC 2021, ASCE 7-16 and ACI 318-19. An earlier code edition, kept for existing projects.

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    <div className="calc-details-head"><span className="calc-card-icon"><Icon icon="calculator" size={20} color="#0076d6" /></span><p className="calc-details-name">Restrained (Basement) Retaining Wall (IBC 2021)</p><a className="calc-details-run" href="https://app.calcs.com/new/sheet/retainingWallRestrainedUSA">Run the calc</a></div>
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  Design restrained retaining walls, commonly basement walls, to IBC 2021, ASCE 7-16, and ACI 318-19. Rankine theory estimates lateral earth pressure with retained soil at-rest or active, optionally. Excludes wind and seismic.
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<Note>
  This calculator uses an earlier code edition (IBC 2021, ASCE 7-16, ACI 318-19). It stays available for existing projects. For new designs, check the [Calculator Library](/docs/calculators/us) for the current edition.
</Note>

## Method & scope

| Property         | Detail                                                                                                                                                                                       |
| ---------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Design standards | IBC 2021, ASCE 7-16, ACI 318-19                                                                                                                                                              |
| Regions          | United States                                                                                                                                                                                |
| Who it's for     | US structural engineers designing restrained (basement) retaining walls to ACI 318-14.                                                                                                       |
| What it checks   | Lateral earth pressure (Rankine theory), Stability checks, Stem flexural and shear design (ACI 318-19, Cl. 22.2 and 22.5), Footing flexural and shear design (ACI 318-19, Cl. 22.2 and 22.5) |

#### What it calculates

US structural engineers designing restrained retaining walls, commonly basement walls, to IBC 2021, ASCE 7-16, and ACI 318-19. Covers Rankine lateral earth pressure theory with at-rest or active soil assumptions, flexural reinforcement design, and one-way shear checks.

Design retaining walls restrained at the top, covering basement configurations the cantilever calculator cannot handle.

#### Calculation method

The Restrained (Basement) Retaining Wall calculator designs propped retaining walls, typically basement walls braced at the top by a floor diaphragm, per IBC 2021, ASCE 7-16, and ACI 318-19. It uses Rankine theory for lateral earth pressure and performs limit state design checks on the wall stem and footing.

##### Lateral earth pressure (Rankine theory)

Lateral soil pressure is estimated using Rankine theory for granular backfill. The calculator supports either at-rest pressure (K\_0 = 1, sin phi, appropriate for restrained basement walls that cannot rotate) or active pressure (K\_a). A triangular pressure distribution is used. The design lateral load H\_total represents the total horizontal force from soil, water table (if present), and surcharge, both dead load (q\_D) and live load (q\_L) surcharge are included.

##### Stability checks

Since overturning is fully prevented by the top restraint, no overturning check is performed. Sliding resistance is verified:

**FS\_sliding = F\_resist / F\_slide ≥ 1.5**

Where F\_resist combines base friction (c\_base × L\_heel) and passive soil resistance in front of the toe. Maximum bearing pressure q\_max is checked against the allowable bearing capacity q\_a.

##### Stem flexural and shear design (ACI 318-19, Cl. 22.2 and 22.5)

The wall stem is designed as a one-way vertical slab spanning between the top restraint and the footing. The governing moment demand M\_u,stem and shear demand V\_u,stem are computed from the tabulated lateral soil load distribution. Capacity checks:

**utilization = M\_u,stem / (phi × M\_n,stem) ≤ 1.0**
**utilization = V\_u,stem / (phi × V\_n,stem) ≤ 1.0**

Combined flexural and axial capacity is also checked for the stem per ACI 318-19 Cl. 22.4, accounting for the weight of soil and wall above.

##### Footing flexural and shear design (ACI 318-19, Cl. 22.2 and 22.5)

The footing is checked for moment demand M\_u,ftg and shear demand V\_u,ftg at the critical sections in the toe. Upward soil pressure on the heel is conservatively neglected for strength design.

**utilization = M\_u,ftg / (phi × M\_n,ftg) ≤ 1.0**
**utilization = V\_u,ftg / (phi × V\_n,ftg) ≤ 1.0**

##### Assumptions and scope

No shear key is modeled. The backfill is flat with no slope. Only dead load surcharge, live load surcharge, wall self-weight, and soil loads are considered. Axial wall loads are not included. Rebar is continuous over the full wall height. Concrete detailing must be checked separately. Expansive soils are not considered.

## How to use it

<Steps>
  <Step title="Open the calculator">
    Open it from **Run calc** in the About this calculator panel above.
  </Step>

  <Step title="Enter your inputs">
    Work through the input sections from top to bottom. Click any input label to see its reference explanation, clause, conditions and assumptions. See [Checks, References, Conditions and Assumptions](/docs/running-calculations/checking-results/checks-references-conditions-assumptions).
  </Step>

  <Step title="Review the results and export">
    Check the utilization of each governing check in the summary, then export a PDF report. See [Views and Export](/docs/running-calculations/exporting-reports/views-and-export).
  </Step>
</Steps>

## Common questions

<AccordionGroup>
  <Accordion title="What design standards does this calculator use?">
    The calculator references IBC 2021 for load combinations, ASCE 7-16 for load factors and lateral earth pressure classification, and ACI 318-19 for reinforced concrete section design. Lateral earth pressure is calculated using Rankine theory, with soil properties (unit weight, friction angle) entered by the engineer.
  </Accordion>

  <Accordion title="What are the key inputs?">
    Key inputs are wall height (retained height), concrete compressive strength (f'c), reinforcement bar size and spacing, concrete cover, soil unit weight, internal friction angle (phi), surcharge loads at grade, and the at-rest or active pressure selection. The wall is assumed restrained at the top (slab or floor diaphragm) and fixed or pinned at the base.
  </Accordion>

  <Accordion title="What does the calculator check and output?">
    The calculator checks flexural reinforcement (moment demand at critical sections versus design capacity), one-way shear capacity of the wall section, and minimum reinforcement ratios per ACI 318-19. It outputs required reinforcement areas, utilization ratios for each limit state, and maximum wall pressures with load combinations.
  </Accordion>

  <Accordion title="When should I use at-rest pressure instead of active pressure?">
    Use at-rest earth pressure (K0) for restrained walls that cannot deflect at the top, which is the typical condition for basement walls braced by a floor slab. Active pressure (Ka) applies when the wall top is free to move. Most basement wall designs use K0 = 1, sin(phi) at-rest conditions per ASCE 7 commentary.
  </Accordion>

  <Accordion title="What limitations apply to this calculator?">
    This calculator assumes no shear keys, no soil inclination at grade, and does not include wind or seismic lateral loads, these must be verified separately. It covers restrained (propped) configurations only. For freestanding cantilever retaining walls, use the Cantilever Retaining Wall (IBC 2021) calculator instead.
  </Accordion>
</AccordionGroup>

## Next steps

<CardGroup cols={2}>
  <Card title="Calculator Library" icon="list" href="/docs/calculators/us">
    Complete list of Calcs.com design calculators available for United States projects (AISC, ACI, NDS, ASCE 7, IBC, and related standards).
  </Card>

  <Card title="Design a Cantilever Retaining Wall (IBC 2021)" icon="calculator" href="/docs/calculators/us/foundations-and-retaining-walls/retainingWallCantileverUSAACI318-19">
    Design concrete or CMU cantilever retaining walls to IBC 2021, ASCE 7-16, ACI 318-19 and TMS 402-16. An earlier edition, kept for existing projects.
  </Card>

  <Card title="Design a Wall Footing to ACI 318-19" icon="calculator" href="/docs/calculators/us/foundations-and-retaining-walls/foundationsWallFootingUSAACI318-19">
    Design continuous wall footings to ACI 318-19 per IBC 2021 or IBC 2024. Results cover ultimate load, bearing capacity and serviceability.
  </Card>

  <Card title="Design a Wall Footing to ACI 318-14" icon="calculator" href="/docs/calculators/us/foundations-and-retaining-walls/foundationsWallFootingUSA">
    Design continuous wall footings to ACI 318-14. An earlier code edition, kept for existing projects.
  </Card>

  <Card title="Design a Restrained (Basement) Retaining Wall" icon="calculator" href="/docs/calculators/us/foundations-and-retaining-walls/retainingWallRestrainedUSAIBC2024">
    Design restrained (basement) retaining walls to IBC 2024, ASCE 7-22 and ACI 318-19, with at-rest or active soil pressure and an optional shear key.
  </Card>
</CardGroup>