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R403.1.3 Footing and Stem Wall Reinforcing in Seismic Design Categories D0, D1 and D2

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Concrete footings located in Seismic Design Categories D0, D1 and D2, as established in Table R301.2, shall have minimum reinforcement in accordance with this section and Figure R403.1.3. Reinforcement shall be installed with support and cover in accordance with Section R403.1.3.5.

For SI: 1 inch = 25.4 mm. 
W = Width of footing, T = Thickness of footing and P = Projection per Section R403.1.1.
NOTES:
  1. See Section R404.3 for sill requirements.
  2. See Section R403.1.6 for sill attachment.
  3. See Section R506.2.3 for vapor barrier requirements.
  4. See Section R403.1 for base.
  5. See Section R408 for under-floor ventilation and access requirements.
  6. See Section R403.1.3.5 for reinforcement requirements.
FIGURE R403.1.3
REINFORCED CONCRETE FOOTINGS AND MASONRY AND CONCRETE STEM WALLS IN SDC D0, D1 AND D2a, b, c, d, e, f
R403.1.3.1 Concrete Stem Walls With Concrete Footings
In Seismic Design Categories D0, D1 and D2 where a construction joint is created between a concrete footing and a concrete stem wall, not fewer than one No. 4 vertical bar shall be installed at not more than 4 feet (1219 mm) on center. The vertical bar shall have a standard hook and extend to the bottom of the footing and shall have support and cover as specified in Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the stem wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing.
R403.1.3.2 Masonry Stem Walls With Concrete Footings
In Seismic Design Categories D0, D1 and D2 where a masonry stem wall is supported on a concrete footing, not fewer than one No. 4 vertical bar shall be installed at not more than 4 feet (1219 mm) on center. The vertical bar shall have a standard hook and extend to the bottom of the footing and shall have support and cover as specified in Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing. Masonry stem walls shall be solid grouted.
R403.1.3.3 Slabs-on-Ground With Turned-Down Footings
In Seismic Design Categories D0, D1 and D2, slabs-on-ground cast monolithically with turned-down footings shall have not fewer than one No. 4 bar at the top and the bottom of the footing or one No. 5 bar or two No. 4 bars in the middle third of the footing depth.
Where the slab is not cast monolithically with the footing, No. 3 or larger vertical dowels with standard hooks on each end shall be installed at not more than 4 feet (1219 mm) on center in accordance with Figure R403.1.3, Detail 2. Standard hooks shall comply with Section R608.5.4.5.
R403.1.3.4 Interior Bearing and Braced Wall Panel Footings in Seismic Design Categories D0, D1 and D2
In Seismic Design Categories D0, D1 and D2, interior footings supporting bearing walls or braced wall panels, and cast monolithically with a slab on grade, shall extend to a depth of not less than 12 inches (305 mm) below the top of the slab.
R403.1.3.5 Reinforcement
Footing and stem wall reinforcement shall comply with Sections R403.1.3.5.1 through R403.1.3.5.4.
R403.1.3.5.1 Steel Reinforcement
Steel reinforcement shall comply with the requirements of ASTM A615, A706M or A996M. ASTM A996 bars produced from rail steel shall be Type R. The minimum yield strength of reinforcing steel shall be 40,000 psi (Grade 40) (276 MPa).
R403.1.3.5.2 Location of Reinforcement in Wall
The center of vertical reinforcement in stem walls shall be located at the centerline of the wall. Horizontal and vertical reinforcement shall be located in footings and stem walls to provide the minimum cover required by Section R403.1.3.5.3.
R403.1.3.5.3 Support and Cover
Reinforcement shall be secured in the proper location in the forms with tie wire or other bar support system to prevent displacement during the concrete placement operation. Steel reinforcement in concrete cast against the earth shall have a minimum cover of 3 inches (75 mm). Minimum cover for reinforcement in concrete cast in removable forms that will be exposed to the earth or weather shall be 11/2 inches (38 mm) for No. 5 bars and smaller, and 2 inches (50 mm) for No. 6 bars and larger. For concrete cast in removable forms that will not be exposed to the earth or weather, and for concrete cast in stay-in-place forms, minimum cover shall be 3/4 inch (19 mm).
R403.1.3.5.4 Lap Splices
Vertical and horizontal reinforcement shall be the longest lengths practical. Where splices are necessary in reinforcement, the length of lap splice shall be in accordance with Table R608.5.4(1) and Figure R608.5.4(1). The maximum gap between noncontact parallel bars at a lap splice shall not exceed the smaller of one-fifth the required lap length and 6 inches (152 mm) [see Figure R608.5.4(1)].
R403.1.3.6 Isolated Concrete Footings
In detached one- and two-family dwellings that are three stories or less in height and constructed with stud bearing walls, isolated plain concrete footings supporting columns or pedestals are permitted.