Properties – Design Criteria (ACI Code):

 

1. General:

Id                            : Unique id for design criteria.

Name                     : Name of the Design criteria.

Design Code         : Design code selected by user. Program allows user to select ay design code for design.    

 

2. Code Parameters:

Tension strain limit : Minimum strain in the reinforcement is limited to this value by the program. If user defined value is less than the suggested by the design code, programs show an error message. The Value less than the code specified is not allowed to provide. User can provide higher value than the code specified.

 

3. Clear Cover:

Inputs for clear cover to top, bottom and side reinforcement.

 

4. Longitudinal rebar limits (%)

Minimum for Tension:

Minimum tension reinforcement is applicable at location where Bending moment exists. Maximum of reinforcement required Bending moment and Minimum for tension would  be provided. This would be provided at each tension face (top and/or bottom) of footing.

Temperature:

If selected for the design, temperature reinforcement would be provided at all locations. This would be provided at each face (top and bottom) of footing.

 

5. Punching shear:

This check is default selected for isolated footing. Option provided to user to skip this check (not recommended).

 

6. One-way shear

This check is default selected for isolated footing. Option provided to user to skip this check (not recommended).

 

Provide shear reinforcement:

Note: Inputs for these settings are disabled in 2024 release.

 

If the given depth of the foundation is not sufficient to satisfy the one-way shear check, program designs the footing with shear reinforcement if this option is selected by user.

 

Check for shear stress:

For Isolated footing, the one-way shear force is calculated for entire width/length of the footing.

 

7. Side face rebar

Note: Inputs for these settings are disabled in 2024 release.

 

Side face reinforcement (SFR or Skin Reinforcement) is provided along perimeter of the foundation. Refer above cross section of the footing showing SFR. There is no reinforcement or cross section design impact of the SFR. Based on the detailing requirements, user can select/unselect this option. Detailing of the SFR would be based on the available rebar diameter and preferred spacing of the longitudinal reinforcement.

 

Provide SFR:

Based on the detailing requirements, user can select/unselect this requirement.

 

% limit:

% SFR to be provided in foundation is an input from user.

 

Effective width:

The effective width and depth of the footing is considered as a cross-section area to compute the area of SFR.

 

8. Crack-width

Note: Inputs for these settings are disabled in 2024 release.

 

The flexural crack-width check is performed for load combinations selected by user. If for a given design parameter and reinforcement provided crack-width check is failed, program will either show a failure for the provided reinforcement or increase the reinforcement.

 

Perform check:

Based on the design requirements, user can select/unselect this check.

 

Allowable crack-width:

The design flexural crack would be less than the allowable crack width limit. 

 

9. Thermal Cracking

Note: Inputs for these settings are disabled in 2024 release.

The phenomenon of initial thermal cracking is important for large volume elements like slab, footings etc. It is related to heat of hydration generated during concrete process and such is not dependent on the analysis.

The principle of detailing to counter ‘initial thermal cracking’ is simple and is based on surface reinforcement in both directions. The amount of reinforcement in %, diameter of bars and spacing of bars, all things are important.

 

Perform check:

Based on the design requirements, user can select/unselect this check.

 

Allowable thermal cracking:

The design thermal crack would be less than the allowable thermal cracking limit. 

 

Peak hydration temperature and Seasonal temperature variation:

The difference between these two values would be considered to perform the thermal cracks in the concrete cross section.

 

10. Detailing

Note: Inputs for these settings are disabled in 2024 release.

 

These inputs are available for detailing of shear reinforcement. If option of providing Shear reinforcement is selected by user and required for the cross-section design of footing, then program provides the shear reinforcement. There are two inputs available to detail the shear reinforcement. As per these inputs, program would provide rebar diameter of shear reinforcement.

 

Preferred Shear Spacing:

The choice is available to user to detail the shear reinforcement with preferred spacing of shear links. The spacing provided would be closer to this spacing as per design requirements. In case, if the detailing is not satisfied with the preferred spacing, program would reduce the spacing to minimum available to satisfy the detailing requirements.

 

Preferred no of legs:

Program will follow the preferred number of shear legs provided by user.