Strip Footing for Bearing Wall per ACI 318-25

Example

A two-story wood-frame bearing wall carries 2.0 kip/ft dead load and 1.0 kip/ft live load. Soil bearing 2500 psf. Design a strip footing per ACI 318-25. Strip footings are designed per unit length (1 ft) for bearing, one-way shear, and flexure.

How StructSuite solves this

StructSuite's free structural design software applies ACI 318-25 Chapter 13 for strip footings: bearing pressure per unit length, one-way shear (§7.4.3), flexure (§7.3), development length (§25.4). Select Strip footing (wall) in Geometry; enter wall loads in Loads. Load combinations per ASCE 7-22 §2.2. Common for residential and light commercial bearing walls.

Steps

1. Step 1: Geometry & Configuration

   Design consideration: Strip width = load per ft / q_a. 3 kip/ft / 2.5 ksf = 1.2 ft → 14–18 in. typical. Thickness for one-way shear (no punching for strip). 8–12 in. thick for 12–18 in. width. Wider footing = less bearing stress; thicker = more shear capacity.

   In StructSuite: Open Step 1: Geometry & Configuration. Under Footing type, select Isolated footing (column) or Strip footing (wall). In the Dimension Lx (ft) input box enter 1.25; in Dimension Ly (ft) enter 1; in Thickness of footing (in.) enter 12. For support, select Column and Concrete (or Masonry/Steel/Wood) and enter column dimensions.

2. Step 3: Load Definition (ASCE 7-22)

   Design consideration: 3 kip/ft (2 D + 1 L) typical two-story wood bearing wall. Dead: studs, sheathing, floors, roof. Live: floor 40 psf × tributary. Heavier walls (masonry, CLT) 4–6 kip/ft. Bearing uses service; shear/flexure use factored.

   In StructSuite: Open the Load Definition section. Click Add load case. For each load case, use the Type dropdown to select D, L, Lr, S, W, E, etc. In the Axial (kips) input box enter the column or wall axial load. Repeat for all load cases. StructSuite applies ASCE 7-22 §2.2 load combinations for bearing, shear, and flexure.

3. Step 2: Materials & Reinforcement

   Design consideration: f'c=2500 psi common for residential strip footings; 3000 psi required in SDC D/E/F per ACI §19.2.1.1. 2500 vs 3000: ~15% difference in √f'c for shear. q_allow 1500 psf without geotechnical; 2000–4000 with report. #4 or #5 bars typical; cover 3 in. min for soil contact.

   In StructSuite: Open the Materials section. In Allowable bearing pressure (psf) enter the value from the geotechnical report or IBC Table 1806.2. In f'c (psi) enter the concrete strength (e.g., 2500). In fy (ksi) enter steel yield. For reinforcement, select bar size and count for X and Y directions. In cover (in.) enter 3 or per spec. ACI 318-25 §19.2.1.1 sets minimum f'c for SDC D, E, F.

Live design (pre-filled)

The form below is the real StructSuite module with example data loaded. Display only—values cannot be changed.