Pier Inspections

Question: Residential & or Commercial Pier(s)
Example: 12 feet deep, 3’ Wide
Obviously, the pier caps are tp remain clean and exposed. How MUCH of the cap is to remain exposed. I have heard 3", where in the IRC or IBC can this be found?

Here Ya Go!:wink:

2009 International Building Code
Chapter 18, Soils & Foundations.

1810.3.11 Pile caps.

Pile caps shall be of reinforced concrete, and shall include all elements to which vertical deep foundation elements are connected, including grade beams and mats. The soil immediately below the pile cap shall not be considered as carrying any vertical load.

  • The tops of vertical deep foundation elements shall be embedded not less than 3 inches (76 mm) into pile caps and the caps shall extend at least 4 inches (102 mm) beyond the edges of the elements.
  • The tops of elements shall be cut or chipped back to sound material before capping.

1810.3.11.1 Seismic Design Categories C through F.
For structures assigned to Seismic Design Category C, D, E or F in accordance with Section 1613, concrete deep foundation elements shall be connected to the pile cap by embedding the element reinforcement or field-placed dowels anchored in the element into the pile cap for a distance equal to their development length in accordance with ACI 318. It shall be permitted to connect precast prestressed piles to the pile cap by developing the element prestressing strands into the pile cap provided the connection is ductile. For deformed bars, the development length is the full development length for compression, or tension in the case of uplift, without reduction for excess reinforcement in accordance with Section 12.2.5 of ACI 318. Alternative measures for laterally confining concrete and maintaining toughness and ductile-like behavior at the top of the element shall be permitted provided the design is such that any hinging occurs in the confined region.

The minimum transverse steel ratio for confinement shall not be less than one-half of that required for columns.

For resistance to uplift forces, anchorage of steel pipes, tubes or H-piles to the pile cap shall be made by means other than concrete bond to the bare steel section. Concrete-filled steel pipes or tubes shall have reinforcement of not less than 0.01 times the cross-sectional area of the concrete fill developed into the cap and extending into the fill a length equal to two times the required cap embedment, but not less than the development length in tension of the reinforcement.

1810.3.11.2 Seismic Design Categories D through F.
For structures assigned to Seismic Design Category D, E or F in accordance with Section 1613, deep foundation element resistance to uplift forces or rotational restraint shall be provided by anchorage into the pile cap, designed considering the combined effect of axial forces due to uplift and bending moments due to fixity to the pile cap. Anchorage shall develop a minimum of 25 percent of the strength of the element in tension. Anchorage into the pile cap shall be capable of developing the following:

1. In the case of uplift, the least of the following: nominal tensile strength of the longitudinal reinforcement in a concrete element; the nominal tensile strength of a steel element; the frictional force developed between the element and the soil multiplied by 1.3; and the axial tension force resulting from the load combinations with overstrength factor in Section of ASCE 7.

2. In the case of rotational restraint, the lesser of the following: the axial force, shear forces and bending moments resulting from the load combinations with overstrength factor in Section of ASCE 7 or development of the full axial, bending and shear nominal strength of the element.

Where the vertical lateral-force-resisting elements are columns, the pile cap flexural strengths shall exceed the column flexural strength. The connection between batter piles and pile caps shall be designed to resist the nominal strength of the pile acting as a short column. Batter piles and their connection shall be capable of resisting forces and moments from the load combinations with overstrength factor in Section of ASCE 7.