Finite Element Based Slab Design Overwrites

Form: Finite Element Based Slab Design Overwrites

Use the Finite Element Based Slab Design Overwrites form to apply design overwrites to the selected slab object(s). The various areas on this form include the following:

Note: For finite element based slab design, the reinforcing is assumed to be placed in the slab object local 1 and 2 axs direction. At drop panel location, the reinforcing is assumed the be placed in the drop panel object local 1 and 2 axis directions.

• Rebar Material drop-down list. Select the rebar material to use in the design strip(s) from the drop-down list of previously defined materials. Rebar material may be defined, edited or reviewed by clicking the button to access the Define Materials form.

• Cover. Chose from the following options to specify the concrete cover over the rebar for the selected slab(s):

• • From Preferences option. Select this option if the cover should be as set in the Design menu > Concrete Slab Design > View/Revise Preferences command. ETABS applies the clear cover specified in the Design menu > Concrete Slab Design > View/Revise Preferences command to the outer layer and assumes that the inner layer is located directly inside the outer layer for both top and bottom rebar. This is the default setting.

  • Specified to Center of Steel option. Select this option to explicitly locate the rebar by specifying the distance to the center of steel in the Direction 1 and Direction 2 Top Cover and Bottom Cover edit boxes.

• Reduced Live Load Factor edit box. Specify a factor to reduce the live load forces used in slab design; most codes allow for live loads to be reduced based on tributary area calculations. The resultant forces in the selected slab object will be multiplied by the Reduced Live Load Factor when used for design. The only forces affected will be those that result from load cases associated with load patterns with a type of REDUCIBLE LIVE, or load cases that have been user defined as REDUCIBLE LIVE using the Design button on the Load Case Data form.

Note: The default value for the Reduced Live Load Factor is 1, which means that there is no reduction; a value of 0.75 would mean that the forces are decreased by 25%.

• Design Option. Choose from the following options to control the design.

• • Design This Slab Object check box. Check this option if design should be performed for the selected slab.

  • Ignore PT When Designing This Slab Object check box. To ignore post-tensioning during design, check this option.

See Also

Strip Based Slab Design Overwrites form

Access the Finite Element Based Slab Design Overwrites form as follows:

1. Select one or more slab object(s) to which the overwrite should be assigned.

2. Click the Design menu > Concrete Slab Design > View/Revise Flxural Design Ovverwrites > FEM Based command.